User:Abyssal/Timeline of ichnology

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Prescientific

19th century

1800s

1802

Spring: A boy named Pliny Moody uncovered a piece of sandstone with mysterious three-toed tracks about 30 cm (1 foot) long while plowing in his father's fields near South Hadley, Massachusetts. The local clergy thought the tracks had been left by the raven Noah sent out from the ark to look for dry land during the Biblical Flood.^[1]

1820s

1820s

A slab of Permian sandstone preserving 24 small footprints came into the possession of the Scottish Reverend Henry Duncan. Duncan visited the quarry where his slab was originally excavated in Corncockle Muir to see if he could find more of the fascinating impressions and successfully recovered more of them. He notified leading paleontologist William Buckland of Oxford University about his discovery.^[2]

Late 1820s

Fossil footprints were reported from Cheshire, England in Triassic rocks known at the time as the New Red Sandstone. This is the earliest written record of fossil footprints now referred to the ichnogenus Chirotherium.^[3]

1828

A newspaper article was published that discussed fossil footprints, and is now regarded as the earliest written record of the subject.^[4]

1830s

1831

Buckland published the first scientific description of fossil footprints about the tracks discovered at Corncockle Muir. He attributed the footprints to ancient tortoises because after having various modern reptiles walk over stretches of pie crust dough, the tracks left by tortoises most closely resembled those from the Permian sandstone.^[4]

1834

A man named Helmut Barth was building a garden house in Hildburghausen, Germany when he discovered strange, hand-shaped tracks in the sandstone he was using in the construction.^[5] Barth's discovery would be named Chirotherium by Johan Jacob Kaup.^[6]

1835

While the streets of Greenfield, Massachusetts were being paved, locals noticed footprints impressed in the stone. The townspeople thought the tracks were left by turkeys.^[1] They informed James Deane, a local doctor and naturalist about the footprints. Deane found the tracks intriguing and wrote to another local scholar, Edward B. Hitchcock about the find.^[7] Hitchcock spent the rest of the summer investigating the local footprints fossils.^[8]

1836

Edward Hitchcock published the results of his research into the fossil footprints. He thought the trackmakers were large flightless birds.^[9]

1840s

1842

Sir Richard Owen supported Buckland's interpretation of the Corncockle Muir tracks as tortoise tracks and named them Testudo duncani.^[4]

1843

James Deane published the results of his own investigations into the fossil footprints of Massachusetts.^[9]

1845

Hitchcock named the ichnogenus Eubrontes.^[10]

1846

Tagart reported dinosaur tracks in England that would later come to be attributed to Iguanodon.^[11]

1847

A man surnamed Cotta wrote a letter including the first documented mention of the many Permian tracks perserved in the "Rotliegendes" of central Germany's Thuringian forest.^[12] "Rotliegendes" is German for "red layers" referring to a Permian sandstone layer rich in rusted iron minerals known elsewhere as the "New Red Sandstone".^[13] The tracks Cotta reported were later named Saurichnites cottae in his honor.^[12]

1848

Hitchcock name the ichnogenus Anomoepus.^[14]

1850s

1850

Sir William Jardine argued against Owen's referral of the Corncockle Muir "tortoise" footprints to Testudo because the name applied to a specific group of modern turtles rather than to footprints. He coined the name Chelichnus, meaning "turtle track" to replace Owen's use of Testudo, but preserved the specific epithet "duncani".^[4]

1851

More Permian Chelichnus tracks were discovered in the highlands of Scotland, not far from Cummingstone.^[15]
Samuel H. Beckles began publishing research on the dinosaur footprints from the Wealden, although he did not recognize their dinosaurian origins.^[16]

1852

Beckles continued to publish research on the dinosaur footprints from the Wealden.^[16]

1854

Beckles continued to publish research on the dinosaur footprints from the Wealden, referring to them as Ornithoidichnites following the nomenclature devised by Edward Hitchcock for some American tracks. Despite his use of a term implying an avian trackmaker, Beckles admitted that he did not know what kind of animals made the tracks.^[16]

1858

Edward Hitchcock published a summary of his research into the fossil footprints of the Connecticut Valley area. He continued to attribute the tracks to large flightless birds that he named their footprints "ornithichnites", meaning "stone bird footprints". He divided the trackmakers into two groups, the leptodactylous birds with narrow toes and the pachydactylous birds with thick toes. He also described seven new ichnospecies for the tracks he studied.^[9] He also described the ichnogenus Grallator.^[17]

1860s

1860

A British scientists surnamed Williamson interpreted the Chirotherium trackmaker as a crocodile.^[18]

1862

Oppel interpreted some tracks from the Solnhofen lithographic limestone as the tracks of pterosaurs.^[19]

1864

Edward Hitchcock died.^[20]

1865

A posthumous "supplement" to Hitchcock's monograph on the Connecticut Valley tracks was published.^[20]

1860: Some English dinosaur footprints were recognzed as Iguanodon tracks. They were the first dinosaur tracks to be recognized as belonging to and individual genus.^[11]

1870s

1877

Thomas Henry Huxley argued against Buckland and Owen's attribution of Chelichnus duncani to ancient tortoises, instead concluding that it was impossible to identify the trackmaker with the knowledge of time.^[15]

1879

Some Welsh dinosaur tracks that had been previously displayed in front of the Jolly Sailor Pub in Newton Nottage were acquired by the Cardiff Museum.^[21]
T. H. Thomas reported the Welsh dinosaur footprints to the scientific literature and noted their similarity to the "Ornithichnites" of Connecticut.^[21]
W. J. Sollas independently published a report of the Welsh dinosaur footprints.^[21]

1880s

Early: Inmates of Nevada's State Prison uncovered a large Pleistocene fossil tracksite while excavating sandstone. The track sites was a lakeshore 50,000 years ago where familiar Ice Age animals like birds, deer, mammoths, and wolves left behind their footprints. However, ten of the roughly 50 trails seemed to have been left by an even stranger trackmaker; a sandaled giant.~NA277~

1884

Large theropod footprints were reported in Late Jurassic rocks at Cabo Mondego, Portugal. These may have been the first European Late Jurassic dinosaur footprints to be documented in the scientific literature.~152~
W. P. Blake reported the fossil footprints discovered at the prison in Carson City, Nevada to the scientific literature.~NA321~
Mark Twain wrote the satirical "The Carson Fossil Footprints" attributing the purported giant tracks discovered there to primitive members of the territorial legislature.~NA279~

1886

A Mr. C. Pooley discovered a small five toed fossil footprint in Oxfordshire, England, which preserved in a Middle Jurassic stratigraphic unit called the Stonesfield Slate.^[22]
John Eyerman discovered two slabs of rock preserving fossil dinosaur footprints near Milford, New Jersey. The trackmaker was probably a small, quadrupedal ornithischian dinosaur.^[23]

1889

Addison Coffin drew up a map of a large portion of the Pleistocene Carson City tracks.~NA280~
Dinosaur footprints were discovered near Goldsboro, Pennsylvania. These tracks are now classified in the ichnogenus Atreipus.^[24]

1890s

Middle Jurassic dinosaur tracks were discovered on the Yorkshire coast of England.^[25]

1894

Othniel Charles Marsh described the new ichnogenus Limnopus for Carboniferous tracks from the coal beds of Kansas.~NA51~

1895

A geology professor named James A. Mitchell discovered some small Grallator tracks in the Late Triassic Gettysburg Formation of Maryland. These are the first and only known dinosaur tracks in the state.^[26]

20th century

1900s

1900

A major Lower Miocene fossil footprint site was discovered at Ipolytarnoc, Hungary. The site preserves more than 1600 individual footprints from a variety of birds and mammals. Avian ichnogenera at the site include Aviadactyla, Ornithotarnocia, Passeripeda, and Tetraornithopedia. Mammalian ichnogenera include Bestiopeda, Carnivoripeda, Megapecoripeda, Mustelipeda, Pecoripeda, Rhinoceripeda. These mammal tracks were left by creatures like carnivorans, peccaries, and rhinoceros. Mastodon tracks have also been reported, but may represent misidentifications.^[27]

1902

Dinosaur footprints were discovered at Fisher's Quarry, near Graterford, Pennsylvania. These tracks are now classified in the ichogenus Atreipus.^[24]

1903

John Bell Hatcher reported probable crocodilian footprints from the Morrison Formation near Canon City, Colorado.~NA177-178~

1904

Richard Swann Lull began studying the Connecticut Valley footprints.^[28] He described the new ichnogenus Anchisauripus, named such because he attributed it to the early sauropod-precursor Anchisaurus.^[17]

1905

Luis Dollo matched the foot of Iguanodon bernissartensis with a purported Iguanodon footprint in "the first attempt to match these tracks with a particular species of the genus".^[29]

1906

Pleistocene human footprints were discovered in the Niaux cave complex of France.^[30]

1908

Paleocene fossil amphibian footprints were discovered in the Fort Union Formation of Montana.~NA246~

1909

Harold Broderick described the three-toed Middle Jurassic dinosaur footprints that had first been discovered during the 1890s at England's Yorkshire coast.^[25]
Fossil Iguanodon footprints were discovered in the rocks of the Wealden Beds at Crowborough, Sussex. These tracks may have inspired Sir Arthur Conan Doyle to write The Lost World.^[16]

1910s

1910

Traces in the genus Octopodichnus were discovered in the Permian-aged Lyons Sandstone of Colorado.~NA44~

1912

A deluxe editions of Sir Arthur Conan Doyle's The Lost World was issued whose cover featured an illustration of the Iguanodon tracks recently discovered at Crowborough, Sussex.^[16]

c. 1914

90 million year old Cretaceous dinosaur footprints were discovered in New Jersey but were accidentally destroyed during an attempt at excavating them.^[24]

1915

Charles Schuchert discovered Carboniferous-aged fossil footprints in the rocks of the Wescogame Formation near the Grand Canyon.~NA34~

1915-1916

Gomes first described the large Late Jurassic theropod footprints from Cabo Mondego, Portugal.^[31]

1918

Lull described the ichnogenus Laoporus.~NA314~

1920s

Charles Whitney Gilmore began collecting and studying the Carboniferous and Permian-aged footprint fossils of the Grand Canyon area on behalf of the Smithsonian. He also constructed an outdoor exhibit about the tracks at Hermit Trail.~NA34~
William Peterson reported the discovery of large three-toed dinosaur tracks preserved in what is now the ceiling of a Carbon County, Utah coal mine. William Diller Matthew attributed these tracks these tracks to tyrannosaurs.~NA217~

c. 1920

Renovations to Oak Hill, the historical home of US President James Monroe, led to the discovery of fossil dinosaur footprints when workers repaved the properties walkways with Lower Jurassic stone. The preserved tracks included Grallator and Eubrontes prints ranging in length from 13 to 33 cm (5–13 inches).^[24] Other local footprints included the tracks of a crocodilian-like animal, Batrachopus. The tracks originated in the Midland Formation.^[32]

1923

Baron Franz von Nopsca published a "seminal" work on fossil amphibian and reptile tracks.^[33] He hypothesized that Plateosaurus was the Chirotherium trackmaker. Although Plateosaurus has only four hind toes and Chirotherium tracks have five impressions, Nopsca followed Willruth's argument that the "thumb" of Chirotherium was composed only of soft tissue and would have left no skeletal record.^[34] He also named the large Late Jurassic theropod fossils discovered at Cabo Mondego, Portugal Eutynichnium lusitanicum. However, this name lacks validity because Nopsca did not formally describe it or designate a type specimen.~154~

1924

J. Henderson reported the first known Paleozoic footprint fossils from Colorado.~NA313~

1925

Wolfgang Soergel interpreted the Chirotherium trackmaker as a pseudosuchian related to, but much larger than, Euparkeria.^[34] He noted that the bulk of the animal's weight was born by its hindlimbs.^[35]
German geologist Adolf Bachofen-Echt reported the first scientifically recognized dinosaur tracks from Croatia. These three-toed tracks were preserved on the Brioni Islands and Bachofen-Echt thought they were made by Iguanodon.~218~

1926

Charles Whitney Gilmore published his first report on fossil footprints from the Grand Canyon area.~NA313~

1927

Comte Begouen reported the presence of an adult human's tracks in the Grotte de Cabarets cave in France. Interestingly, these tracks are accompanied by impressions left by the human's walking stick.^[36]
Charles Whitney Gilmore published his second report on fossil footprints from the Grand Canyon area.~NA313~

1928

Charles Gilmore described the Paleocene amphibian tracks from the Fort Union Formation of Montana. He named the new ichnospecies Ammobatrachus montanensis for the tracks. He observed that these were the first Paleocene fossil footprints to be documented in the scientific literature.~NA246~
Potential Paleocene mammal footprints were reported from Alberta.~NA247~
Charles Whitney Gilmore published his third report on fossil footprints from the Grand Canyon area.~NA313~

1929

Hernandez-Pacheco described an Oligocene-aged fossil bird track site at Peralta de la Sal, Spain.^[37]
90 million year old Cretaceous carnivorous dinosaur footprints were discovered at the Hampton Cutter Clay Works quarry at Woodbridge, New Jersey.^[24]

1930s

Bradford Willard discovered a new ichnogenus Devonian-aged trace fossils in Pennsylvania that he named Paramphibius because he thought the trackmaker was a transitional form between fishes and tetrapods. He named a new taxon, the Ichthyopoda to classify this creature.~NA37-38~
Permian-aged fossil footprints were reported from the Abo Formation near Las Cruces, New Mexico.~NA57~
The University of Michigan Museum of Paleontology bought several slabs of Late Triassic fossil footprints collected near Mesa Redonda, New Mexico. Among the preserved tracks were three-toed reptile footprints and the four-toed ichnogenus Pseudotetrasauropus that may have been left by a primitive sauropodomorph.~NA88~
Roland T. Bird discovered a new Early Jurassic dinosaur tracksite in the Moenave Formation of northwestern Arizona. Although the site's location would be lost, Bird's photographs would help Dinosaur National Monument paleontologist Scott Madsen relocate the site decades later.~NA118~
Dinosaur tracks were excavated from the Dakota Group near Lamar, Colorado. These tracks are now exhibited by the Denver Museum of Natural History.~NA201~
Late: An expansion of the Nevada State Prison was built over the Pleistocene fossil footprints that had been discovered there. However, some specimens had been collected before and are now curated by the Nevada State Museum.~NA280~

1930

1930: Amateur paleontologist Charles Strevell privately published a description of various Cretaceous dinosaur footprints he collected from the coal mines of Carbon County, Utah. Strevell named the tracks "Dinosauropodes" at the advice of Earl Douglass after Strevell had failed to interest Richard Swann Lull or Walter Granger in studying the tracks themselves. Strevell named many ichnospecies of "Dinosauropodes" in this publication, but none are considered valid because he published outside of the traditional scientific literature, failed to cite any other ichnological works, and referred too wide variety of dissimilar tracks to "Dinosauropodes".~NA217-219~
More Cretaceous dinosaur footprints were discovered at the Hampton Cutter Clay Works quarry at Woodbridge, New Jersey. The largest tracks discovered in the quarry were 19 inches long.^[24]

1931

Fredrick von Huene reported the presence of Early Jurassic fossil footprints that were probably left by an evolutionary precursor to mammals in the Botucatu Sandstone of Brazil.~NA144~
Maurice Mehl erected the new ichnogenus Ignotornis for some bird tracks preserved in the Dakota Group near Golden, Colorado. These were the first scientifically documented Mesozoic bird footprints.~NA194-195~ The bird in question as interpreted as a "small shorebird or wader".~NA211~ The site would eventually be heavily collected and all of its tracks were presumed removed.~NA194-195~

1932

Edward Branson and Maurice Mehl reported the presence of Carboniferous-aged fossil footprints of a new ichnospecies in the Tensleep Formation of Wyoming.~NA34~ They named the tracks Steganoposaurus belli and attributed them to an amphibian nearly three feet in length.~NA34-35~
Edward Branson and Maurice Mehl named a new kind of Late Triassic dinosaur footprint discovered in the Popo Agie Formation of western Wyoming. The new ichnogenus and species was named Agialopus wyomingensis.~NA93-94~
Dinosauropes~NA320~

1933

Two Anchisauripus tracks were discovered near Yocumtown, Pennsylvania.^[38]
Late Triassic dinosaur footprints were discovered near Gettysburg, Pennsylvania.^[38]
Carlton S. Nash found some more dinosaur footprints near the original location of Pliny Moody's track discovery in Massachusetts.^[39]

1934

Bradford Willard of the Pennsylvania Topographic and Geologic Survey discovered a dinosaur footprint near New Cumberland, Pennsylvania.^[38]~

1936

Toepelman and Rodeck made the first report on fossil arthropod trackways in the Lyons Sandstone and fossil vertebrate footprints preserved in the Fountain Formation.~NA314~

1937

The Dinosaur Ridge dinosaur tracksite was discovered near Denver, Colorado. Tracks include those made by ornithopods and theropods. Some of the ornithopod tracks seem to have been left by individuals traveling together and are thus evidence for social behavior.~NA196-197~ Further, these ornithopods seem to have traveled predominately on all fours, unlike most ornithopod tracks, which were made by bipeds.~NA197~
The New York Times reported that Barnum Brown had discovered the fossil footprints of a huge and unknown kind of dinosaur in a Wyoming coal mine. Brown's claim was simply a "publicity stunt" aimed at attracting funding.~NA219-220~ However, Brown's report attracted the attention of a coal mine operator from the Cedaredge, Colorado area named Charlie States, who reported large dinosaur footprints spaced five meters apart in his mine, the Red Mountain Mine.~NA220~ Brown and his assistant Roland Bird oversaw an "ambitious" excavation of the purported giant's tracks. After three weeks of 24 hour labor on the part of the miners and the development of specialized equipment to extract the specimen, a 17 foot long slab of track-bearing rock was taken from the mine and shipped to the American Museum of Natural History in New York.~NA220-221~
More Late Triassic dinosaur footprints were discovered near Gettysburg. These tracks ranged from chicken-sized to 15 cm (6 inches) in length.^[38]
Elmer R. Haile Jr. collected Late Triassic reptile tracks from the Trostle Quarry near York Springs, Pennsylvania. The preserved ichnogenera included the dinosaur ichnogenus Atreipus and other reptile traces like Brachychirotherium and Rhynchosauroides.^[38]

1938

Kenneth Caster conclusively demonstrated that unusual fossil tracks from the Solnhofen lithographic limestone variously attributed to creatures like Archaeopteryx, little dinosaurs, or pterosaurs were actually made by horsehoe crabs, as specimens had been found literally "dead in their tracks".^[19] Similar fossils in the United States had been attributed to a transitional form between fishes and tetrapods by Bradford Willard earlier in the 1930s.~NA37-38~
Roland T. Bird discovered four sauropod and theropod trackways in the Early Cretaceous Glen Rose Formation of Texas.
Brown published a description of the dinosaur tracks with the purported giant stride length. He tried to keep up his charade of there being an undiscovered mystery dinosaur by downplaying "the obvious hadrosaurian affinity of the tracks".~???NA220-221~

c. 1939

Nash bought the Massachusetts property where he discovered dinosaur footprints. He would begin excavating and selling the dinosaur footprints on his land and the property would come to be known as Nash Dinosaur Land.^[39]

1939

Lionel F. Brady began experimenting with living arthropods to help determine which sorts of arthropods may have produced various ancient trace fossils.~NA43~
Sumner Anderson reported the presence of small carnivorous dinosaur footprints between 15 and 20 cm in length preserved in the Early Cretaceous Lakota Formation at two different sites in South Dakota.~NA184-185~
Earl L. Poole of the Public Museum and Art Gallery discovered a new Late Triassic dinosaur track site at a quarry near Schwenksville, Pennsylvania.^[38] The dozens of tracks preserved there were mostly left by chicken-sized dinosaurs, but about a "half dozen" of them were left by turkey-sized trackmakers.^[40] Poole ascribed these tracks to the ichnogenus Anchisauripus. One footprint was left by a dinosaur with about the same body mass as a horse.^[39] This site is now known as the Squirrel Hill Quarry.^[38]

1940s

Example of a camel from the White River Formation.

Frank Peabody performed "extensive" research on Early Triassic fossil footprints.~NA71-72~

1940

Roland T. Bird oversaw the excavation of sauropod and theropod tracks from the Paluxy River in Texas. This was the first large-scale dinosaur track excavation in history.~NA199~
Frank Peabody studied the early Pliocene fossil amphibian footprints of the Sierra Nevada Mountains of California. He found them to be almost identical to the tracks of their descendants. This was his first major contribution to ichnology.~NA274~

1941

Friedrich von Huene named the ichnogenus Coelurosaurichnus for small three-toed carnivorous dinosaur tracks discovered in northern Italy.^[41]
Bird described his experiences excavating dinosaur tracks for the American Museum of Natural History in Texas.~NA318~
H. H. Nininger reported the presence of fossilized lion footprints in Arizona.~NA321~

1943

Robert Chaffee reported the presence of a tracksite from Wyoming preserving the footprints of a camel-like even-toed ungulate and a rhinoceros-like odd-toed ungulate in the Oligocene-aged White River Beds. He noted that only two other Oligocene fossil tracks were known and neither had been described.~NA257~ Chaffee attributed one of these, a partial print preserved in the Yale Peabody Museum, to a brontothere.~NA257-258~

1944

Bird described the Davenport Ranch dinosaur tracksite.~NA318~

1947

F. E. Peabody argued that the "horseshoe-like" impressions reported from the Moenkopi Formation were actually "current crescents".~NA316~

1948

Casteret reported the presence of Pleistocene hyena tracks in the Aldene cave of France.^[42]
F. E. Peabody published a study of the amphibian and reptile tracks preserved in the Triassic Moenkopi Formation. Lockley and Hunt would later regard this paper as "a classic" in the field.~NA316~

1949

Pleistocene human footprints were discovered in the Niaux cave complex of France.^[30]

1950s

Oligocene to Miocene-aged bird tracks were first reported from the "Molasse" rocks of Switzerland.^[43]
Frank Peabody performed "extensive" research on Early Triassic fossil footprints.~NA71-72~
A rock hound named Al Look "embellished" Barnum Brown's mystery dinosaur hoax, informally naming the creature "Xosaurus". He also reported having encountered another dinosaur trackway with a similarly long stride as Brown's original specimen. This trackway supposedly recorded the huge mystery dinosaur stepping on a crocodile-like reptile.~NA221~

1951

Albert de Lapparent and others restudied the large Late Jurassic theropod tracks of Cabo Mondego.^[31] They thought the tracks were made by Megalosaurus.^[44]
Henry Faul and Wayne Roberts reported the presence of Early Jurassic fossil footprints in Colorado's Navajo Sandstone. These tracks were probably left by an evolutionary precursor to mammals.~NA144~

1952

Wilhelm Bock reinterpreted the footprints discovered in the Squirrel Hill Quarry as Grallator and non-dinosaurian archosaur tracks. He also described the ichnospecies Anchisauripus gwynnedensis for a dinosaur track discovered in the North Pennsylvania Railroad tunnel near Gwynned. These tracks are now thought to belong to Atreipus, however.^[39]

1953

Pennsylvanian-aged footprint fossils were discovered in the Minturn Formation near Dotsero, Colorado.~NA36~
Lull published a "[c]lassic monograph updating the work of Edward Hitchcock."~NA317~

1954

Frank Peabody renamed Ammobatrachus montanensis Ambytomichnus montanensis due to their resemblance to the modern newt family Ambystomidae. He observed that these were the oldest known salamander footprints.~NA246~

1955

A French ichnologist named Lessertisseur erected the ichnogenus Megalosauripus. He attributed the Cabo Mondego tracks to a megalosaurid.^[45] He also named the ichnogenus Tyrannosauripus, but as both ichnogenera lacked type species and type specimens these taxonomic names were invalid.^[46]
M. F. Farmer published the locations of many track sites in northern Arizona.~NA312~

1957

Albert de Lapparent and Zybyszewsky published further research on the large Late Jurassic theropod tracks of Cabo Mondego.^[31]
The new ichnospecies Limnopus cutlerensis was described from the Permian-aged Cutler Group in Colorado.~NA51~
Lee Stokes erected the new ichnogenus Pteraichnus for fossil footprints discovered in the Morrison Formation of Utah that he thought were left by pterosaurs.~NA144~
Curry published research on the fossil footprints of the Eocene Green River Group.~NA321~

1958

Oskar Kuhn named the new Early Cretaceous theropod ichnogenus and species Buckeburgichnus maximus from Germany. It is notable in its preservation of a large hallux impression.^[47]

1959

Brady and Seff reported the presence of fossil mammoth footprints near Montezuma Castle National Park in Arizona.~NA321~

1960s

*Deinotherium*, a proboscidean from Miocene Romania.

Ticinosuchus.

An important Late Triassic dinosaur tracksite was discovered northeast of Dinosaur National Monument.~NA93-94~

1960

July 30: A team of 36 geologists set out on a field trip to Spitzbergen in preparation for the 21st International Geological Congress.^[48]
August 3rd: Albert de Lapparent and Robert Lafitte stumbled on some fossil footprints left by a large bipedal dinosaur at Isfjorden, Spitzbergen.^[49] The researchers suspected that the tracks were made by a carnosaur. At 78 degrees of latitude north, these were the highest latitude dinosaur tracks known in the world, up from the previous record of 56 degrees.^[50]
A geologist named H. D. Curry working for the Shell Oil Company discovered a slab of rock preserving high quality three-toed mammal footprints in Utah's Strawberry Canyon. The trackmakers were probably Eocene relatives of modern tapirs and horses. Curry donated the so-called "Strawberry Slab" to the Smithsonian Institution.~NA252-253~

1961

Lionel F. Brady began experimentation with living arthropods for the identification of fossil trackmakers concluded.~NA43~

1962

Albert de Lapparent reinterpreted the dinosaur tracks from Spitzbergen. Although mentioning their initial impression that the tracks were carnosaurian, he concluded that the tracks were probably left by Iguanodon instead, due to their lack of claw marks, rounded toe prints, and general similairty to the feet of Iguanodon bernissartensis.^[50]
Panin and Avram published research on Miocene fossil bird and mammal tracks from the vicinity of the Carpathian Mountains of Romania. They attributed the local bird footprints to four different families, the anatids, ardeids, charadriids, and gruids. Contemporary mammalian trackmakers included artiodactyls, cats, dogs, and relatives of modern elephants. The latter of these left behind one thoroughly trampled site with an area of more than 100 sq m. The researchers erected several new ichnotaxa for the tracks they studied and similar tracks would later be discovered elsewhere in Europe.^[51]

1963

Dinosaur tracks were reported from a site on France's western coast.^[52]
Justin Delair named the new ichnogenus and species Purbeckopus pentadactylus for tracks preserved in the Purbeck Limestone of Dorset, England. He was unable to confidently identify the trackmaker, but speculated that they may be crocodilian in origin.^[53]
Natasha Heintz documented the return expedition to Spitzbergen to make plaster casts of the Spitzbergen dinosaur tracks. Although the casts were made, the effort was frought with difficulty because the intense cold and high humidity hindered the plaster's ability to set.^[50]

1964

Jean-Claud Plaziat observed that previous researchers had underestimated the abundance of Tertiary bird footprints fossils in Europe.^[54]

1965

A large pseudosuchian named Tichinosuchus was named for remains found in Swiss Triassic rocks. It had the right size and anatomy to account for the Chirotherium tracks of Europe and is considered the most likely trackmaker.^[55]
Panin published more research on the fossil bird footprints from the Carpathian vicinity.^[56]
de Raaf, Beets, and Kortenbout van der Sluijs reported the presence of a large number of well-preserved web-footed bird tracks from Oligocene rocks in Spain.^[57] The high percentage of the fossil trails being oriented in the same direction suggests that this deposit records evidence for flocking in these ancient birds. This is extraordinary because evidence for social behavior in fossil bird footprints is very uncommon.^[37]

1966

R. M. Alf described Miocene-aged fossil footprints discovered in the Mojave Desert.~NA321~

1967

Albert de Lapparent and Christian Montenat published the results of their research on the dinosaur tracks reported from western France in 1963.^[52] They identified the rocks preserving the tracks as part of a geologic formation called the Infralias and track sites were found in at least seven different positions in the local stratigraphy. The changing paleoenvironments implied by the local geology led the researchers to conclude that this series of dinosaur track beds spanned the Triassic-Jurassic boundary.^[58]
Two dinosaur trackways were discovered in the Roach Stone of Acton, England.
B. R. Erickson published research on the Eocene bird tracks preserved in the Green River Group of Utah.~NA321~

1968

Casamiquela and Fasola named the ichnogenus Iguanodonichnus for some apparent iguanodont tracks in South America.
Raymond Alf demonstrated that tracks similar to arthropod trace fossils from the Coconino Sandstone are produced by large modern tarantulas.~NA43~

1969

Bessonat, Dughi, and Sirugue described an Oligocene bird and mammal track site at Veins, France.^[59]
March: A coal miner working near Hayden, Colorado hit his head on the natural cast of a dinosaur footprint while in pursuit of a run-away coal cart. The impact injured his spinal cord, leading to his death 10 days later.~NA227~

1970s

Location of Culpeper, Virginia.

Mid: Dinosaur tracks of the ichnogenera Atreipus and Grallator were discovered in a quarry that straddles the Virginia-North Carolina border. These may be the oldest dinosaur tracks known in the eastern United States.^[60]

Late: The publication of a formula capable of inferring the life speeds of dinosaurs from their fossil trackways brought further attention to Barnum Brown's claim of having discovered the tracks of a mystery dinosaur with an abnormally long stride length. Scientists instantly recognized the footprints as belonging to a duck-billed hadrosaur rather than some completely unknown dinosaur, but the validity of the trackway's stride length proved controversial. Dale Russell and Pierre Beland accepted Brown's measurement and calculated the trackmaker as moving at 27 kilometers and hour. Tony Thulborn argued that a footprint left by another dinosaur obscured a track left by the original trackmaker roughly halfway between the prints composing the supposedly enormous stride. This implied that the trackmaker's stride was only half the claimed size and it was probably only traveling at about 8.5 kilometers and hour.~NA221~

1970

Leonard Wills and Bill Sarjeant reported potential dinosaur footprints from Triassic rocks in Nottinghamshire and Worcestershire. Ichnotaxa reported included Coelurosaurichnus, Otozoum, and Swinertonichnus. The rocks were of uncertain age at the time of the authors writing and are now known to have been Lower Triassic.^[61] Dinosaur tracks dating to the Early Triassic would be anomalous as their skeletal remains are not known until later in the period.^[62] Not suprisingly, the dinosaurian status of the tracks reported by Wills and Sarjeant have been disputed.^[61]
Sarjeant found the three-toed Middle Jurassic dinosaur footprints comparable to the Cretaceous ichnogenus Saltapliasaurus from Russia.^[63]
Pleistocene human footprints were discovered in the Niaux cave complex of France.^[30]
Hartmut Haubold named the Brazilian proto-mammal tracks Tetrapodichnus.~NA144~

1971

Haubold formally named the German ichnospecies Metatetrapous valdensis from Germany's Wealden Beds. He noted that it was similar to the Canadian ichnospecies Tetrapodosaurus borealis, which dates back to the Aptian or Albian. These ichnotaxa may represent fossil ankylosaur footprints.^[64]
de Clercq and Holst published on the Upper Oligocene bird tracks of Lucerne, Switzerland. The tracks, which the researchers concluded were left by rails, were left in the fine-grained sediments at the top of a 15 roughly stratigraphic interval characterized by gradually decreasing particle size.^[43]
Hartmut Haubold erected several new ichnogenera for fossil footprints discovered in Colorado. The proto-mammal tracks that Faul and Roberts reported he named Bipedopus coloradensis and Semibipedopus meekerensis.~NA144-145~ He also named the new ichnogenus Lacertipus for the small tracks in the formation that were apparently left by a lizard-like animal.~NA145~
Samuel Welles named two new Early Jurassic theropod ichnogenra from the Kayenta Formation of northeastern Arizona; Dilophosauripus and Kayentapus.~NA119~ also Hopiichnus.~NA318~

1972

Vialov classified fossil bird footprints as members of the ichno order Avipedia.^[56]
Pleistocene human footprints were discovered in the Niaux cave complex of France.^[30]
David Webb studied the fossil footprints left by ancient camels and determined that even these ancient forms shared modern camels' "pacing gait", where the animal moves both legs on one side of the body at the same time, unlike most mammals which move hindlimbs and forelimbs from the opposite sides of the body in each step. Webb argued that the energetic efficiency of the pacing gait enabled camels' success in desert and prairie environments where significant distances may separate food and water sources.~NA267~
Paul Olsen and Robert F. Salvia discovered dinosaur Late Triassic footprints in the Stockton Formation of Nyack Beach State Park, New York. The tracks included 12–15 cm (5–6 inch) long Grallator tracks. Possible Atreipus tracks were also found there. The regions's non-dinosaurian tracks included Apatopus, Brachychirotherium, Chirotherium, and Rhynchosauroides.^[65]

1973

Justin Delair and A. B. Lander reported the presence of three parallel dinosaur trackways in the Roach Stone of Herston, England.
A significant Permian-aged fossil tracksite in the Cedar Mesa Sandstone of Utah was inundated following the creation of the Glen Canyon Dam. This tracksite preserved an apparent predator-prey interaction wherein the trail left by a small amphibian or reptile vanished at the point where it intersected with the trail left by a large carnivorous proto-mammal. Fortunately for ichnologists, plaster casts of the trackways and photographs remain available for study.~NA55-56~
W. J. Breed reported fossil goose footprints from the Pliocene Bidahochi Formation of Arizona.~NA321~

1974

Kaever and de Lapparent named the new ichnogenus and species Elephanotpides barkhausensis for the poorly preserved tracks of a large quadrupedal dinosaur discovered near Barkhausen, Germany. The trackmaker was probably a sauropod.^[66]

1975

A fossil footprint was discovered in the Upper Permian Val Gardena Sandstone. The track would later become known as Pachypes dolomiticus and is apparently the first pareiasaur track ever discovered.^[67]
Bill Sarjeant described the five-toed Middle Jurassic footprints discovered by C. Pooley and named it Pooleyichnus burfordensis in his honor.^[22] Sarjeant proposed that this unusual track may have been made by a mammal.^[68]
A large tracksite preserved in the late Eocene Vieja Group of Texas was first studied in a University of Texas research program.
Robert E. Weems was informed of, and began researching, a Late Triassic reptile track site in a quarry near Culpeper, Virginia.^[69]

1976

Miguel Antunes published a cursory description of the Late Jurassic sauropod tracks of Cabo Espichel, Portugal.^[70]
The Continental Shelf Institute staged an expedition to Spitzbergen that uncovered yet more dinosaur tracks.^[71]
Leon Pales described the Pleistocene human footprints of France's Niaux cave complex. This paper has been considered "one of the most comprehensive studies of cave footprints ever published."^[30]
R. McNeil Alexander published a formula for inferring the speeds of dinosaurs from their fossil trackways.~NA312~
Russell and Beland examined Brown's claim to have discovered the tracks of a running dinosaur.~NA320~
Weems continued to excavate and study the Late Triassic reptile track site near Culpeper, Virginia.^[69]

1977

Several hundred Late Triassic dinosaur footprints were reported from the vicinity of Cardiff, Wales.^[72] This report was made by M. E. Tucker and T. P. Burchette.^[73]
Terry Logue reported the presence of fossil pterosaur footprints in the Sundance Formation.~NA160~
By this point, Weems found the Late Triassic reptile track site near Culpeper, Virginia to be roughly an acre in size and preserving 32 different reptile trackways, including those left by dinosaurs.^[69]

1978

Marc Edwards and others reported the dinosaur footprints discovered in Spitzbergen in 1978. Only two footprints were discovered at the site, which was an exposure of the Helvetiafjellet Formation. The researchers interpreted the tracks as carnosaur footprints, but now they are thought to have been left by iguanodontids.^[71]
Stokes observed that tracks left by close evolutionary relatives of mammals were common and widespread in the Navajo Sandstone. He found such tracksites in Colorado, Idaho, and Utah.~NA145~ He reported many new sites in the Navajo formation.~NA318~

1979

A 36 cm wide, 18 meter long Middle Carboniferous trackway that was apparently left by the giant millipede-like Arthropleura was reported from the Island of Arran.^[74]
Carme Lompart reported the presence of Late Cretaceous dinosaur tracks in the Ager Valley of Spain, near the country's border with France.^[75]
Marc Weidmann and Manfred Reichel published a "lengthy" review of the Oligocene to Miocene aged bird tracks found in Switzerland's "Molasse" rock.^[43] They reported the presence of tracks left by one kind of duck, two kinds of herons, one kind of perching bird, and four kinds of waders.^[76] Weidmann and Reichel devoted intense effort to classifying these tracks based on previous schemes devised by scholars like Avram, Panin, and Vialov for other bird track sites.^[56] They also worked diligently to discern the tracks' positions within the stratigraphic column.^[77]
Stokes and Madsen published more on the purported pterosaur footprints from the Jurassic Navajo Sandstone of Utah.~NA318~

1980s

Hypsilophodon.

An aetosaur.

Researchers interpreted large vertical burrows in the sediments of the Lower Triassic Chinle Formation as having been made by lungfish. Now, however, the burrows are attributed to arthropods similar to modern crayfish.~NA77-80~ Hasiotis and Mitchell '89~NA315~
Lockley and Hunt returned to the Late Triassic dinosaur tracksite discovered northeast of Dinosaur National Monument to collect specimens for the University of Colorado and United States Geological Survey.~NA93-94~
Lockley and Hunt studied a coal mine near Gunnison, Colorado. They found many hadrosaur trackways, apparently left by a herd traveling in a southerly direction.~NA221-223~
Mid: A new dinosaur track site in the Dakota Group was discovered just outside of Roxborough State Park. The park was later to acquire the land where the specimens were preserved.~NA200-201~
Mid: Dinosaur footprints were first reported from the Laramie Formation.~NA229~

1980

Donald Baird attributed the ichnogenus Navahopus of Arizona's Navajo Formation to a prosauropod trackmaker.~NA89~ He also describedit.~NA316~
Gerard de Beaumont and Georges Demathieu hypothesized that sauropods walked on the knuckles of their forelimb, and this explains why so many sauropod foreprints lack any impression left by the large claws born on the first toe in many species.~E141~
Luis Aguirrezabla and Luis Viera reported a new kind of theropod footprint from Bretun, Spain. It would later be named Filichnites.^[78]
Paul Ellenberger reported the presence of Eocene artiodactyl and bird tracks near Garrigues, France. There were several kinds of mammals tracks, including Anoplotheripus, Diplartiopus, Hyaenodontipus, Lophiopus, Palaeotheripus, and Ucetipodisus. Ellenberger thought that Anoplotheripus was made by the ruminant Anoplotheripus. Diplartiopus he attributed to a different kind of even-toed ungulate. Hyaenodon was though to have left Hyaenodontipus. Ellenberger thought that the proto-tapir Lophiodon produced the Lophiopus tracks. He attributed Palaeotheripus to the small hore-like animal Palaeotherium. He though a small arboreal primate-like animal left tracks of the ichnogenus Ucetipodisus. He named the bird tracks present at the site Ludicharadripodiscus.^[79]
Don Baird erected the ichnogenus Navahopus for footprints preserved in the Early Jurassic Navajo Formation. He thought these tracks were left behind by a small prosauropod.~NA145~
A nine meter long Pleistocene bear trackway was reported from Lake County, Oregon. The tracks themselves were about 40 cm long, suggesting a trackmaker roughly the size of a large modern bear. These tracks may have been left by an Arctotherium.~NA275-276~
Olsen argued that the ichnogenera Grallator, Anchisauripus, and Eubrontes actually represent a growth series.~NA317~
R. L. Laury described fossil "tracks associated with mammoth skeletons" in Hot Springs, South Dakota.~NA321~
Walter P. Coombs, Jr. interpreted some unusual Eubrontes tracks from Dinosaur State Park of Rocky Hill, Connecticut as traces left by a swimming theropod because the tracks only preserved impressions from the tips of the animal's toes as if the rest of its body weight was supported by water.^[80]

1981

Alfred Hendricks named the ichnospecies Rotundichnus munchehagensis for some "wide-gauge" sauropod tracks preserved in the rocks of the Berriasian-aged Buckeburg Formation. Seven trails were present in all and their arrangement showed evidence for herding behavior among the trackmakers.^[81]
Giuseppe Leonardi erected the new ichnogenus and species Brasilichnium elusivum to classify the Early Jurassic proto-mammal tracks from the Botucatu Sandstone of Brazil. This work has since been praised as "very thorough" by Martin Lockley and Adrian Hunt.~NA145~
Thulborn criticized the the idea that the hadrosaur tracks reported by Brown in 1938 were left by a running animal.~NA320~

1982

Demathieu and Haubold described the new Early Triassic ichnogenus and species Isochirotherium archaem from Germany. As only the hind prints are preserved in this trackway it may represent the oldest evidence in the world for the existence of animals with bipedal gaits. However, while intriguing, their remains the possibility that the track maker was a quadruped and its foreprints eroded away before the trail was discovered.^[82]
Demathieu and Marc Weidmann described a new Triassic fossil tracksite from Swtizerland called the Vieux Emosson tracksite.^[83] The authors named nine ichnospecies and several new ichnogenera, although none of these new ichnotaxa would be subequently observed at other sites. The poor preservation, anomalously high ichnodiversity, and lack of corroboration at other sites cast doubts on he legitimacy of the researchers' ichnotaxa, however.^[84]
Bernier and others erected the ichnogenus Chelonichnium and interpreted it as the tracks of a large turtle.^[85]
Edwin McKee reported the presence of apparent horseshoe-shaped trace fossils in the Carboniferous Esplanade Sandstone that he attributed to a tetrapod. However, these tracks are more likely to have been invertebrate traces or artifacts of erosion.~NA36~

1983

Geology student Jeff Pittman recognized that the "potholes" hindering excavation equipment traffic through a gypsum mine in southeastern Arkansas were actually sauropod dinosaur footprint.~NA191-192~

1984

Hartmut Haubold published the Saurierfahrten.~E50~ Haubold was a German ichnologist,and the Saurierfahrten a specialist's handbook for identifying Carboniferous and Permian fossil footprints. It was the only publication of its type in the world at the time and only available in German.~E33-34~
Paul Olsen and Peter Galton argued that Ellenberger had oversplit the Late Triassic and Early Jurassic ichnotaxa he studied and that many of the kinds of tracks he regarded as distinct were actually the same as tracks previously described in eastern North America.^[86]
J. E. Andrews and J. D. Hudson reported the first dinosaur tracks to be scientifically documented in Scotland. The tracks are three-toed and preserved in the Middle Jurassic Leate Shale.~144~
Hans Mensink and Dorothee Mertmann described the new ichnogenus and species Gigantosauropus asturiensis from Jurassic near Asturias, Spain. The researchers attributed the tracks to a theropod. At 1.35 m in length, these tracks were actually twice as long as those of a more typical length for a large theropod.^[66]
Bernier and others named the new ichnogenus and species Saltosauropus latus for strange widely spaced tracks discovered in France. They interpreted the traces as those left by a hopping dinosaur.~173–174~
Lompart erected two new ichnogenera and species for the three-toed Late Cretaceous dinosaur footprints she reported from Spain. The new ichnotaxa were Ornithopodichnites magna and Orcauichnites garumeniensis. Lompart thought both were made by ornithopods, but they are now thought attributable to theropods. Also, because these footprints were poorly preserved and the ichnotaxa not properly named, the names are regarded as being of dubious scientific utility.^[87] Sauropod tracks were also reported from the site.^[88]
George Demathieu and others described an Oligocene bird and mammal track site from southeastern France. Three different mammalian ichnotaxa were present. One was an artiodactyl track they named Bifidipes velox. The second was the largest of the three, Ronzotherichnus, was apparently left by the rhinoceros Ronzotherium. A creodont or early carnivoran left behind the third kind of tracks, which the researchers named Sarcotherichnus enigmaticus. They named the bird tracks at the site Pulchravipes magnificus.^[59]
Kevin Padian and Paul Olsen reinterpreted the supposed pterosaur tracks named Pteraichnus from the Morrison Formation of Utah as crocodilian tracks.~NA145~
L. D. Agenbroad published an interpretation of the preservation of mammoth remains and footprints at Hot Springs, South Dakota.~NA320~

1985

Luis Aguirrezabala reported the presence of nine parallel trails left by Hypsilophodon or one of its close relatives in Lower Cretaceous rocks of La Rioja, Spain. This tracksite is now known as the Valdevajes site.^[89]

1986

An international symposium for paleontologists performing research on "Dinosaur Tracks and Traces" was held in New Mexico.^[90] The gathering was a success and "led to the rejuvenation and maturing of the discipline of dinosaur ichnology".^[91]
Haubold observed that during the Late Triassic, small Grallator tracks become common.^[73] Haubold published a discussion of archosaur tracks from near the Triassic-Jurassic boundary and their distribution through the stratigraphic column.~NA315~
Pennsylvanian-aged footprint fossils were discovered in the Minturn Formation of Hermit Peak in Colorado.~NA36~
Paul Olsen and Kevin Padian reported the presence of the crocodilian ichnogenus Batrachopus in the Early Jurassic Moenave.~NA145~
Paul Olsen and Kevin Padian discovered Batrachopus tracks in the Navajo Formation, but did not publish their findings.~NA145~
Lockley and Martin showed that some of the purported baby dinosaur footprints collected by William Wilson from Utah were "enhanced" by carving.~NA226~
Kirk Johnson discovered a new Paleocene fossil tracksite in the Fort Union Formation. This site preserved additional amphibian tracks as well as the tracks of two different wading birds and traces of insect activity. The tracks were preserved in what was once the banks of an ancient stream~NA246~
Scrivener and Bottjer published a census of tracks from the Miocene Copper Canyon Formation of Death Valley National Monument, California. Most of these footprints were camel tracks, but bird and horse prints were also common. Less common traces included those of bear-dogs, cats, deer, and proboscideans.~NA269-270~
Joseph Thomasson, Michael Nelson, and Richard Zokrzewski determined that some Miocene grasses from the Oglalla Formation of Kansas used C4 photsynthesis based on pieces of grass that had been trampled down into the sediments by the area's ancient wildlife.~NA271~
Jordan Marche argued that the Pleistocene tracks discovered by prisoners near Carson City, Nevada deserved more scientific attention than they had received.~NA276~
Houck and Lockley published the first illustrations of the foosil footprints preserved in the Belden Formation.~NA313~
Olsen and Baird published "[a] detailed study of the ichnogenus Atreipus."~NA316~
Lockley, Houck, and Prince first described the Purgatoire Valley dinosaur tracksite.~NA317~

1987

Paul Ensom reported dinosaur tracks from the Purbeck Limestone of Dorset, England as the latest Jurassic dinosaur footprints known from Europe.^[92] Ensom interpreted these trace fossils as sauropod footprints.^[93] The tracks were preserved only 2m below the horizon representing the consensus Jurassic-Cretaceous boundary. Since then the tracks have come to be regarded as Early Cretaceous.^[92]
David Norman suggested that smaller species of Iguanodon may have walked on their hind legs while larger and heavier species may have preferred to walk on all fours.^[89]
Giuseppe Leonardi also referred the Navajo Formation tracks examined by Olsen and Padian to Batrachopus.~NA145~
Lockley disputed Robert T. Bakker's hypothesis that an Early Cretaceous sauropod trackway from the Davenport Ranch, Texas area preserves evidence that sauropods traveled in herds with the young surrounded by the adults to protect them from predators. Instead, Lockley interpreted this trackway as a herd of sauropods traveling through a narrow area, with the young following the adults.~NA186~
Lockley and Hunt began studying the dinosaur tracks of the Dakota Group at the Alameda Parkway site, which is now called Dinosaur Ridge.~NA209~
Conrad, Lockley, and Prince published a thorough description of the fossil footprints preserved in the Triassic Sloan Canyon Formation and Sheep Pen formations.~NA314~
Lockley and Jennings published the first illustration of the fossil footprints preserved in the Late Triassic rock of Colorado's Dolores Valley.~NA315~
Lockley described the ichnogenus Caririchnium. This publication was also the first detailed treatment of the Dakota Group's trace fossil record in the scientific literature.~NA319~
Robert E. Weems described the new ichnospecies Gregaripus bairdi from a rock quarry in Virginia. The ichnospecies epithet was chosen to honor Donald Baird. Gregaripus dated back to the Late Triassic and were left by a trackmaker that walked on hind feet less than four inches long, with three toes and blunt nails.^[94] This suggests that the Gregaripus trackmaker was a small ornithischian dinosaur about 1.5 meters (five feet) long.^[95] Robert E. Weems published the results of his research into the Late Triassic reptile tracksite near Culpeper, Virginia. Among the fossil footprints he found there were the dinosaur ichnogenera Agrestipus, Grallator, Gregaripus, and Kayentapus.^[69]

Weems also describe the new ichnogenus and species Agrestipus hottoni. The species epithet was chosen in honor of Nicholas Hotton III. Weems attributed these three to four-toed tracks as sauropod footprints, but now they are thought to have been left by the sauropods' slightly more primitive relatives, the prosauropods.^[96]

1988

Ensom published further research on the Purbeck Limestone dinosaur tracks from Dorset.^[92]
Harald von Walter and Ralf Werneberg reported the discovery of body impressions left behind by diplocaulid amphibians in the Rotliegende of the Thuringian Forest area. The assemblage includes the body impression of several individuals, all no more than a few centimeters in length.~46~ The authors named these traces Hermundurichnus fornicatus.^[97]
Bahn and Vertut reported the presence of Pleistocene fox tracks in the Fontanet cave of France.^[42]
Lockley and Hunt rediscovered fossil bird footprints in the Dakota Group near Golden Colorado.~NA194-196~ Among the specimens recovered was the first in the world to preserve dinosaur and bird footprints together.~NA196~
Lockley and Prince expanded on their previous descriptive work on the Purgatoire Valley dinosaur tracksite.~NA317~
Lockley reported the first observation in the Dakota Group of dinosaur footprints with preserved skin impressions.~NA319~
W. A. S Sargeant and J. A. Wilson reported the presence of Eocene mammal footprints in Texas.~NA322~

1989

Demathieu reported potential dinosaur footprints from the Middle Triassic of France.^[98]
Dana Batory and William Sarjeant proposed that the 1909 discovery of Iguanodon footprints at Crowborough, Sussex was Sir Arthur Conan Doyle's inspiration for writing The Lost World.^[16]
R. Santamaria, G. Lopez, and M. L. Casanovas-Cladellas reported an Oligocene mammal track site discovered near Agramunt, Spain. This tracksite preserved four new ichnospecies, three of which were in new ichnogenera. First was a new species of Bothriodontipus, which was made by the pig-like animal Bothriodon or a close relative. The researchers new ichnogenera were Creodontipus and Plagiolophustipus.^[59] They classified two of their new ichnospecies in Creodontipus, an ichnogenus they fittingly attributed to creodonts. They attributed Plagiolophustipus to tapir-like animals distantly related to horses.^[99]
Jeff Pittman proved that the sauropod tracks he recognized in an Arkansas gypsum mine were actually at the same level of the geologic column as the Glen Rose Formation sauropod tracks of Texas.~NA192~
A research group headed by Lockley and Hunt, along with a collaborator from Japan, excavated the co-ocurring dinosaur and bird footprints from Colorado. The three ton specimen was shipped to Japan to star in a traveling museum exhibit about dinosaur footprints.~NA196~
Lee Parker and John Balsley reported the presence of potential Hesperornis footprints in a coal mine near Price, Utah.~NA223~ They might actually be pterosaur tracks.~NA224~ Lockley, Matsukawa and Hunt described the specimen.~NA320~
L. S. Bowlds published an early report on the Permian fossil footprints of the Abo Formation in the Robledo Mountains.~NA312~
Lockley reported the presence of fossil footprints in the Minturn Formation.~NA313~
Prince and Lockley further expanded on their earlier descriptions of the Purgatoire Valley dinosaur track site.~NA317~
Farlow, Pittman, and Hawthorne described the ichnogenus Brontopodus.~NA318~
April: A quarry worker named Robert Clore blasting stone near Culpeper, Virginia uncovered a new Late Triassic reptile tracksite. This site was apparently about 300,000 years older than the first Late Triassic tracksite discovered near Culpeper and had an even greater area of about 6 acres.^[100] Weems began studying the site that same year, and reported the presence of 4,000 individual tracks. The local tracks included the dinosaur ichnogenera Grallator and Kayentapus. Other tracks may have been left by aetosaurs.^[101]
Michael J. Szajna and Brian W. Hartline discovered Late Triassic reptile footprints in an excavation for a housing development near Reading, Pennsylvania.^[102]

1990s

Location of Croatia in the European Union.

1990

Thulborn disputed the referral of a trace fossil found in a core sample taken from the Early Triassic Bunter Sandstone to the dinosaur ichnogenus Coelurosaurichnus. He hypothesized that its trackmaker was actually a horeshoe crab.^[61] Thulborn also disputed the supposed theropodan origin of the ichnogenus Gigantosauropus of Asturias, Spain. Instead, he concluded, the Gigantosauropus trackmaker was actually a sauropod.^[66] Thulborn also disputed the interpretation of Saltosauropus latus put forward by the team of French researchers who first described the ichnogenus as the tracks of a hopping dinosaur. Thulborn found this interpretation inconsistent with the expected morphology and spacing a hopping dinosaur would produced. His own interpretation of Saltosauropus was that it represents marks left by a sea turtle swimming just above the seafloor.^[103]
Ryszard Fuglewicz and others reported fossil trackways from the Holy Cross Mountains of Poland that may be the oldest Triassic trackways in Europe. They reported tracksites at six different positions within a stratigraphic series in several distinct paleoenvironments including river channels and floodplains. The ichnogenera they identified in these tracksites included Brachychirotherium, Capitosauroides, Isochirotherium, Rhynchosauroides, and Synaptichnium.^[104]
Demathieu reported the presence of dinosaur tracks at Saint-Leons and Saint-Laurent de Tives in the Causses region of France.

^[105]

Hunt, Lucas, and Huber published the first in-depth description of the fossil footprints preserved in the Sangre de Cristo Formation.~NA313~
Lockley published the "[f]irst map of an Otozoum trackway from the western states." He also noted the presence of tracks resembling Brasilichnium and attributed them to a tritilodont.~NA317~
Currie, Nadon, and Lockley described Cretaceous ornithopod tracks that preserved impressions of the trackmakers' skin.~NA318~
Lockley disputed claims that some sauropod tracks were left underwater by swimming trackmakers.~NA319~

1991

Geologists Anders Ahlberg and Mikael Siverson reported the discovery of a dinosaur track in a railroad tunnel in southern Sweden. The rocks preserving the print are part of a stratigraphic unit called the Hoganas Formation which straddles the Triassic-Jurassic boundary.^[106]
Gierlinski reported the presence of Hettangian theropod tracks in the Holy Cross Mountains of Poland.^[107]
Lanzinger and Leonardi reported ornithopod tracks among the dinosaur footprints at Lavini de Marco, Italy.^[108]
Lockley disputed Paul Ensom's interpretation of some dinosaur tracks from the Purbeck Limestone of Dorset, England as sauropod footprints and instead suggested that they were probably made by ankylosaurs.^[92]
A track site containing more than 250 fossil bird footprints was discovered ear Villar del Rio, Spain.^[109]
Casanovas-Cladellas and others reinterpreted the purported hypsilophodontid tracks of the Valdavajes site in Spain as theropod footprints in a heavily criticized paper.^[89]
Robison reported shorebird footprints in the Cretaceous Mesa Verde Group of Utah. He also reported the presence of the oldest known frog tracks.~NA225-226~
Brand and Tang published the controversial argument that the fossil footprints of the Permian Coconino Sandstone were made underwater by swimming animals.~NA312~
Lockley described the Moab megatracksite.~NA317~

1992

dos Santos and others observed that at the Portugese Carenque dinosaur tracksite fossil shells and small vertebrate fossils were more common inside dinosaur footprints than untrodden portions of the same rock. Apparently the compression of the sediment under the dinosaur's foot somehow led to more favorable conditions for fossilization than were present elsewhere in the ancient trackmaking environment.~E232~ They also found that the purported South American iguanodont ichnogenus Iguanodonichnus was actually probably made by a sauropod.^[11]
C. Lancis and A. Estevez reported the presence of early Pliocene tracks preseved near Alicante, Spain. Among the mammals who left their mark here were members of the horse family and bears. The bear that left its track there were probably either a species in the genus Agriotherium or Ursus ruscinensis.^[110]
Farlow observed that sauropod trackways could be categorized as either being "narrow-gauge" or "wide-gauge".~NA175~
Mid November: Lockley and Hunt's research group at the University of Colorado undertook one of the few major dinosaur footprint excavations in history in order to expand the exposed track-bearing surface at Dinosaur Ridge for an outdoor interpretive center. To do so they collaborated with the Friends of Dinosaur Ridge and the Jefferson County Scientific and Cultural District to remove a one meter thick layer of sandstone via "precision blasting".~NA199-200~
May 3rd: The Seattle Times reported the discovery of a potential Diatryma track in the Eocene Puget Group of Flaming Geyser State Park, Washington.~NA262~
July 17th: Another Seattle reported that Allison Andors and other researchers had determined that the large bird track discovered in Flaming Geyser State Park was a hoax carved into the rock. Other researchers would subsequently conclude that the track was genuine after all.~NA262~
Lockley argued against Brand and Tang's hypothesis that the fossil footprints of the Coconino Sandstone were made underwater.~NA313~
Lockley and Madsen published ichnological evidence for the predation of large reptiles on smaller animals during the Permian period.~NA313-314~
Loope argued against Brand and Tang's hypothesis that the fossil footprints of the Coconino Sandstone were made underwater.~NA314~
Lockley and others published the "[f]irst report of Atreipus sensu stricto in the western states."~NA315~
Lockley, Conrad, and Paquette published a summary of Dinosaur National Monument's recently discovered Late Triassic fossil footprints.~NA315~
Lockley and others described a new fossil track site at Cub Creek that preserved the first known instance of the ichnogenus Pseudotetrasauropus in the western US.~NA315-316~
Lockley and others described the new bird-like ichnospecies Trisauropodiscus moabensis.~NA317~
Olsen and others argued that a supposed Otozoum foreprint was actually the hind prints of two small theropods impressed on top of eachother into a single impression.~NA317~
Lockley and others summarized the state of science's knowledge about the fossil footprints preserved in the Dakota Group megatracksite.~NA319-320~
Greben and Lockley published an "[o]verview of the Eocene Green River tracks."

1993

Demathieu reported the presence of dinosaur tracks the Causses region of France.^[105]
Whyte and Romano argued that the ichnogenus Deltapodus, which they named, was left behind by a sauropod.~135~
Lockley and dos Santos described the Kimmeridgian-aged Avelino quarry tracksite near Lisbon, Portugal, the first scientifically documented sauropod dinosaur tracksite in Europe to contain well-preserved tracks of the animals' front feet. The quarry contained only one track-bearing layer with five intersecting sauropod trails. Although the animals varied in size all had hindprints smaller of 30 cm or less in length, suggesting that they were juveniles.^[111] They also argued against the idea that sauropod trackways consisting mainly of foreprints were left by swimming animals.~NA320~
Lockley, Meyer, and dos Santos performed fieldwork mapping the dinosaur tracks at Cabo Espichel, Portugal.^[70]
Meyer reported the first scientifically documented Late Jurassic dinosaur footprints from Switzerland. These tracks were discovered near the town of Lommiswil.^[112]
Parkes reported theropod tracks in the Ashdown beds of the Wealden near Hastings, Sussex.^[113]
Moratalla first used the name of the theropod ichnospecies Therangospodus oncalensis in the scientific literature, although it had not yet been described. He also informally coined the ichnogenus Filichnites.^[114]
Viera and Torres argued that contrary to the reinterpretation published the previous year by Casanovas-Cladellas and others, the dinosaur footprints of the Spanish Valdavajes site were hypsilophodontid tracks after all.^[89]
Martin-Escorza also published a paper arguing for the hypsilophodontid status of the Valdavejes dinosaur tracks.^[89]
Scientists began studying the recently discovered fossil footprints at Las Hoyas, Spain.^[115]
Dalla Vecchia, Tarlao, and Tunis reinterpreted the supposed Iguanodon tracks reported by Bachofen-Echt from Croatia as theropod tracks.
Claude Guerin and George Demathieu described the new ichnospecies Dicerotichnus laetoliensis. This ichnospecies was left behind by a late Pliocene rhinoceros of fairly modern build, possibly from the genus Diceros. Its tracks are preserved at the same site known for its ancient hominid tracks.~E246~
A non-technical article in the Spanish magazine Blanco y Negro discussed the wide variety of Miocene tracks preserved at Salinas de Anana, Spain.^[116]
J. Quintana reported the presence of Quaternary-aged footprints on the Balearic island of Menorca. The most conspicuous tracks were those of the extinct goat Myotragus, but tiny footprints left by the mouse genus Hypnomys were also preserved in places where blocks of fallen sandstone sheltered them from the elements.~264~
Lockley, Hunt, and Meyer synonymized Navahopus with Brasilichnium, and noted that these tracks were common among the Early Jurassic sand dunes of the Western Hemisphere.~NA146~
Lockley and Hunt introduced the idea of ichnofacies to the scientific literature. They described and named the Brontopodus ichnofacies based on sauropod tracksites in Texas.~NA210~^{[citation needed]}
A new tracksite was discovered in Toadstool Park area of Nebraska's Oglalla National Grassland.~NA260~ The tracks were left across a kilometer-long stretch of what was once an ancient river valley, but is now part of the White River Group.~NA260-261~ Eleven different trackmakers have been documented here, including camels, carnivorans, ducks, rhinoceroses, and shorebirds.~NA261~ Some of the mammals seem to have been moving in herds.~NA261-263~ Dixon-LaGarry-Guyon~NA321-322~
Hunt and others described the fossil footprints of the Robledo Mountains.~NA313~
Hunt, Santucci, and Lockley reported the first therapsid tracks to have been discovered in the Moenkopi Formation.~NA315~
Lockley and Hunt described a new fossil tracksite and accompanying ichnotaxa preserved in the Triassic Sloan Canyon Formation of New Mexico.~NA315~
Szajna and Shaymaria M. Sylvestri described the Late Triassic reptile tracks discovered near Reading, Pennsylvania. They found most of the tracks to belong to ichnogenera like Apatopus, Brachychirotherium, Chirotherium, Gwynnedichnium, and Rhynchosauroides, although dinosaur tracks like Atreipus and Grallator were also present.^[102]
Late: An expansive Late Triassic dinosaur tracksite was discovered at the Pennsylvania State Correctional Institution in Graterford.

^[117] At least three different ichnospecies were preserved in the local Lockatong Formation rocks, including the dinosaur tracks Atreipus and Grallator ranging from 9 to 15 cm (3.5–6 inches) long.^[118]

Other tracks included possible Gwynnedichnium or Rhynchosauroides tracks up to 2 cm (0.8 inches) long.^[69]

1994

Jenkins and others reported the presence of Late Triassic dinosaur tracks from the Fleming Fjord Formation of eastern Greenland. Most of the reported footprints were Grallator, but there were some prints apparently left by prosauropods. These tracks may be referable to the ichnogenus Tetrasauropus.

Gierlinski and Ahlberg reported additional Triassic-Jurassic dinosaur footprints from southern Sweden.^[106]
Whyte and Romano continued to regard the ichnogenus Deltapodus as being sauropod tracks.~135
Lockley and others argued that Deltapodus was probably not left by a sauropod because the hind prints had only three toes and the tracks themselves were preserved in an environment where sauropod tracks are not generally found.~135~ Instead they concluded it was more likely to be the tracks of a thyreophoran, possibly a stegosaur.^[119]
A cave enthusiast near Fatima, Portugal looked down on a quarry from a high ridge and noticed that its floor was covered in sauropod footprints.^[120] The site included the longest known dinosaur trails at the time. The individual tracks are the largest sauropod prints known from the Middle Jurassic and include the largest foreprints of any known sauropod track type.^[121]
Lockley and others reported that nearly two thirds of sauropod tracksites known to science were located in Europe. One was in Germany, sixteen were in Portugal, two in Spain, and eleven were in Switzerland for a grand total of thirty across the continent overall.^[122]
Lockley, Meyer, and dos Santos published the result of their project mapping the tracks of Cabo Espichel, Portugal.^[70] They found eight separate track-bearing layers at the site, the second of which preserved evidence of sauropod social behavior. This layer contains seven trails left by an apparent herd of immature sauropods.^[123]

Lockley, Hunt, and Meyer defined the Brontopodus ichnofacies.

Moratalla and others observed that at this point in time only 4 Early Cretaceous sauropod track sites were known from the La Rioja Province of Spain.^[81]
Dalla Vecchia published futher research on the Croatian dinosaur footprints he reinterpreted as theropod tracks.
Galopim published The Battle of Carenque, a book describing the successful efforts of Portugese conservationists to save the home of the world's longest dinosaur trackway from being destroyed by freeway construction.~E229-230~
A major collaborative research venture between the US Bureau of Land Management, the New Mexico Museum of Natural History, the Smithsonian, and the University of Colorado began aimed at studying the Permian-aged tracks of the Abo Formation in New Mexico.~NA57-61~
Terry Logue maintained that there were pterosaur footprints preserved in the Sundance Formation despite the popular opinion that such tracks were left by crocodilians.~NA160~
Bill Sarjeant and Wann Langston published a monograph on the late Eocene track site from the Vieja Group of Texas. The tracks preserved there indicate a fauna including six kinds of bird, two kinds of invertebrate, nineteen mammal species, and two kinds of turtle.~NA256~
Hunt, Lockley, and Lucas reported the existence of a fossil trackway preserving an apparent act of predation of a pelycosaur upon a small reptile.~NA313~
Lockley, Hunt, and Meyer proposed the idea of vertebrate ichnofacies.~NA314~
Lockley and Hunt published a review paper summarizing the state of science's knowledge about the Mesozoic fossil tracksites preserved in the western United States.~NA319~
Lockley and Hunt "[d]efine[d] the Brontopodus and Caririchnium ichnofacies."~NA319~

1995

Iwan Stossel reported the oldest known fossil vertebrate footprints in Europe to the scientific literature.~E29~ The tracks were preserved in the Mid-Late Devonian Valentia Slate of Valentia Island, which lies off the southwestern coast of Ireland. Roughly 150 tracks were present in an 8 meter long trail left behind by an early tetrapod.~E29-30~
David Scarboro and Maurice Tucker reported the discovery of a fossil trail probably left by a temnospondyl amphibian about 1.5 meters long walking through a delta during the Middle Carboniferous. The find is one of the largest Carboniferous fossil trackways in all of Europe. The estimated size of the trackmaker indicates an the presence of an amphibian larger than any known from England's body fossils dating back to the same time period.~E34~
Geoffrey Tresise proposed that Chirotherium tracks exhibit sexual dimorphism. The ichnospecies C. stortonense is slender and Tresise hypothesized was made by a female trackmaker while the ichnospecies C. barthi was thicker and may have been made by the male. This publication was the first to propose sexual dimorphism based on trace fossil morphology rather than just size.^[124]
Gerard Gierlinksi reinterpreted the ichnogenus Otozoum, generally regarded as prosauropod tracks, as the footprints of the primitive armored dinosaur Scelidosaurus. However, he would later retract this interpretation and return to the traditional prosauropod interpretation.^[125]
Moratalla and others published research on the fossil tracks from Las Hoyas Spain. They attributed some unusual three-toed tracks at the site to turtles.^[115]
Lockley and others reinterpreted the supposed turtle tracks from Las Hoyas, Spain as pterosaur footprints based on a recent increase in pterosaur trace fossils being discovered all around the world.^[115]
Leonardi and Lockley argued that use Friedrich von Huene's ichnogenus name Coelurosaurichnus should be abandoned because it refers to the same kind of footprint as Grallator.
Demathieu and Sciau described the dinosaur tracks at Sauclieres in the Causses region of France.^[105] They reported the presence of the dinosaur ichnospecies Dilophosauripus williamsi, Grallator minisculus, Grallator saucilierensis, and Grallator variabilis. They also reported the presence of the non-dinosaurian ichnospecies Batrachopus deweyi.^[105]
Avanzini reported the theropod ichnogenus Eubrontes among the fossil dinosaur footprints at the Lavini de Marco track site in Italy. They also reported tracks of the ichnogenus Parabrontopodus which were likely made by a small-to-medium-sized sauropod.^[108]
Cyril Ivens and Geoffrey Watson published Records of Dinosaur Footprints on the North Coast of Yorkshire, documenting the many local dinosaur track discoveries.^[63]
Jean-Michel Mazin and others described the first scientifically documented pterosaur fossils from Europe. These tracks were preserved in a Late Jurassic limestone in Crayssac, France.^[126] The pterosaurs that left these footprints seem to have been in the sparrow to sea gull size range. These tracks have played a "pivotal" role in confirming that various unusual and controversial trace fossils reported around the world really were made by pterosaurs after all.^[127]
April: Fabio Dalla Vecchia and one of his students were arrested while mapping dinosaur footprints in Croatia and inadvertently following the tracks into a military zone. They were tried and subsequently fined their trial expenses and released.~E217-218~
Koenigswald, Walders, and Sander described a 30,000 to 20,000 year old Pleistocene fossil mammal track site from Bottrop, Germany. This ste was discovered on the grounds of a sewage treatment plant. Local trackmakers included bison, horses, cave lions, reindeer, and wolves. The cave lion tracks are notably the first to be discovered outside of an actual cave.~E257~
Price argued that scholars generally underestimated how long ago humanity first domesticated horses based on a Bronze Age tracksite in Sweden.~E265~
Phylis Jackson argued that the pedal anatomy of Anglo-Saxon and Celtic peoples are so distinct that these populations can be distinguished based on feet alone going all the way back to the Neolithic.~E268~ Celtic people have narrower feet while Anglo-Saxon feet are broader.~E269~

1996

King and Benton^{[disambiguation needed]} disputed Thulborn's attribution of the Early Triassic Bunter Sandstone Coelurosaurichnus to a horsehoe crab because they didn't think the supposed tracks were tracefossils at all instead they interpreted the apparent tracks as sedimentary structures of geological rather than biological origin. They referred Sarjeant's supposed Otozoum and Swinertonichnus to Chirotherium.^[61]
Bill Sarjeant reclassified the supposed Early Triassic dinosaur fossils he reported from England in 1970. He originally reported the presence of two Coelurosaurichnus species. However he had since concluded that one of these Coelurosaurichnus species was actually referable to the ichnogenus Batrachopus and the other to Plectoperna.^[61] He reclassified his supposed Otozoum specimens as Paratetrasauropus and attributed Swinertonichnus to crocodilians.^[98]

Lockley and others reported the presence of the ichnogenera Pseudotetrasauropus and Tetrasauropus among the dinosaur footprints reported from the Cardiff, Wales area by Tucker and Burchette in 1977. These tracks may have been left by a prosauropod.^[73]

Brigitte Lange-Badre reported the first Late Jurassic sauropod footprints to have been discovered in France.^[128]

Fuentes Vidarte reported the oldest known bird tracks in the world from the Berriasian Wealden Beds of the Villar del Rio, Spain. There were more than 250 individual prints at the track site and Fuentes Vidarte named the new ichnogenus and species Archaeornithopus meijidei for them.^[109]

Fabio Dalla Vecchia returned to Croatia and finished mapping the dinosaur footprints with Croatian geologist Igor Vlahovic.~E218~

Fabio Dalla Vecchia and Marco Rustioni reported a Miocene mammal tracksite in the Conglomerato di Osoppo in Udine Province, Italy. Across its 100 square meter area the track site preserved the footprints of three different kinds of large mammal.^[51] Dalla Vecchia and Rustioni attributed these tracks to a large bovid, Hipparion, and what may be a small rhinoceros.^[129] The sediments preserving these tracks are coarser than those of most fossil track sites.^[51]

1997

The first international workshop on Paleozoic footprint fossils, presided over by Hartmut Haubold was held in Germany. The assembled scholars visited many significant German Paleozoic track sites and museum collections.^[90] The symposium was such a success that it is regarded as a turning point in the history of Paleozoic vertebrate ichnology.^[91]
Gierlinski reported the presence of possible small sauropod footprints in Early Jurassic rocks fromt the Holy Cross Mountains of Poland.~E122~

Avanzini, van den Dreissche and Keppens found that there were no ornithopod prints among the tracks preserved at Lavini de Marco in Italy and the only dinosaur groups to leave behind footprints there were the sauropods and theropods.^[108] They concluded that the tracks were cemented through chemical processes trigger by the rapid evaporation of water from the carbonate track-bearing substrate and speculated that similar circumstances may have preserved tracks in carbonates at other sites and different positions in the stratigraphic column.^[130]
Meyer reported that the Late Jurassic dinosaur tracks discovered near Lommiswil, Switzerland were actually part of a gigantic megatracksite. This was the first report of a dinosaur megatracksite in Europe.~E171~
Jean-Michel Mazin and others published further research on the pterosaur tracks of Crayssac, France.^[126]
Wright and others re-examined the Purbeckopus pentadactylus tracks from Dorset, England and concluded that not only were they pterosaur tracks, but they were among the largest known pterosaur tracks in the fossil record.^[53]
Joaquin Moratalla and Jose Sanz found theropod tracks to compose 80% of the fossil footprints in Spain's Cameros Basin, with the remaining 20% consisting mostly of ornithopods (16%) and sauropods (4%).^[131]
Casanovas and others reported that by this point in time 10 Early Cretaceous sauropod track sites had been discovered in La Rioja Province, Spain.^[81]
Felix Perez-Lorente reported evidence for quadrupedal locomotion among Berriasian iguanodont footprints preserved in the Villar del Arzobispo Formation not far from Galve, Spain.^[132]
Tuner and Anton attributed Miocene cat footprints found at Salinas de Anana, Spain to the genus Pseudaelurus. These tracks may in fact be the oldest known cat footprints in the world.^[116]
Yuong-Nam Lee erected the new ichnogenus Magnoavipes preserved in the Cenomanian Woodbine Formation of Texas. The trackmaker was aparently a waterbird of great size, with slender-toed feet 19–21 cm long.~NA212~
Phylis Jackson published further research on the use of pedal anatomy and footprints to distinguish different groups of people.~E268~

1998

Sarjeant, Delair, and Lockley named the ichnogenus Iguanodontipus for some English dinosaur tracks probably made by Iguanodon.
Lockley, dos Santos, and Hunt found the purported hypsilophodont tracks of the Spanish Valdavajes tracksite similar to the Late Jurassic ichnogenus Dinehichnus that has been attributed to dryosaurids.^[89]
Lopez-Martinez and others noted the presence of sauropod and ornithopod tracks near the K-T Boundary in the Tremp Formation of northeastern Spain. The presence of tracks so close to the Cretaceous-Tertiary suggests that the dinosaur died out rapidly rather than gradually.~E239~

Footnotes

^ ^a ^b Weishampel and Young (1996); "Footprints in Stone," page 58.
^ Lockley and Meyer (2000); "Earliest Discoveries," page 25.
^ Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 53.
^ ^a ^b ^c ^d Lockley and Meyer (2000); "Earliest Discoveries," page 27.
^ Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," pages 53–54.
^ Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 54.
^ Weishampel and Young (1996); "Footprints in Stone," page 59.
^ Weishampel and Young (1996); "Footprints in Stone," pages 59–60.
^ ^a ^b ^c Weishampel and Young (1996); "Footprints in Stone," page 60.
^ Weishampel and Young (1996); "Theropoda: Skeletons. Fires, and Footprints," page 113.
^ ^a ^b ^c Lockley and Meyer (2000); "1. What Are the Correct Ichnogenus and Species Names to Use for These Tracks?" page 195.
^ ^a ^b Lockley and Meyer (2000); "Rotliegendes: Permian Trackway Heaven," page 39.
^ Lockley and Meyer (2000); "Rotliegendes: Permian Trackway Heaven," page 38.
^ Lockley and Meyer (2000); "Tracking in the Holy Cross Mountains, Poland," page 118.
^ ^a ^b Lockley and Meyer (2000); "Earliest Discoveries," page 28.
^ ^a ^b ^c ^d ^e ^f Lockley and Meyer (2000); "Iguanodon and Conan Doyle's Lost World," page 201.
^ ^a ^b Weishampel and Young (1996); "Theropoda: Tracking and Attacking in the Triassic," page 98.
^ Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 56.
^ ^a ^b Lockley and Meyer (2000); "Turtles and Hopping Dinosaurs," page 178.
^ ^a ^b Weishampel and Young (1996); "Footprints in Stone," page 61.
^ ^a ^b ^c Lockley and Meyer (2000); "Welsh Dinosaurs at the Jolly Sailor Pub," page 79.
^ ^a ^b Lockley and Meyer (2000); "Mr. Pooley's Enigmatic Track Discovery," page 143.
^ Weishampel and Young (1996); "More Early Footprints," page 62.
^ ^a ^b ^c ^d ^e ^f Weishampel and Young (1996); "More Early Footprints," page 63.
^ ^a ^b Lockley and Meyer (2000); "Dinosaurs in the Great Deltas of Yorkshire," page 133.
^ Weishampel and Young (1996); "More Early Footprints," pages 62–63.
^ Lockley and Meyer (2000); "A Miocene Menagerie," page 255.
^ Weishampel and Young (1996); "More Early Footprints," page 61.
^ Lockley and Meyer (2000); "2. Were the Tracks Made by Representatives of the Genus Iguanodon Only, and If So, Which Species?" page 195.
^ ^a ^b ^c ^d ^e Lockley and Meyer (2000); "Subterranean Tracking: Hominid Ichnology," page 261.
^ ^a ^b ^c Lockley and Meyer (2000); "Megalosaur Tracks," page 152.
^ Weishampel and Young (1996); "Virginia (Midland Formation)," page 105.
^ Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," pages 56–57.
^ ^a ^b Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 57.
^ Lockley and Meyer (2000); "Tracks as Keys to Evolution and Locomotion," page 60.
^ Lockley and Meyer (2000); "Subterranean Tracking: Hominid Ichnology," page 262.
^ ^a ^b Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 252.
^ ^a ^b ^c ^d ^e ^f ^g Weishampel and Young (1996); "More Early Footprints," page 64.
^ ^a ^b ^c ^d Weishampel and Young (1996); "More Early Footprints," page 66.
^ Weishampel and Young (1996); "More Early Footprints," pages 64–66.
^ Lockley and Meyer (2000); "Von Huene's Little Dinosaur Track: Coelurosaurichnus," page 95.
^ ^a ^b Lockley and Meyer (2000); "Subterranean Tracking: Hominid Ichnology," page 260.
^ ^a ^b ^c Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 248.
^ Lockley and Meyer (2000); "Megalosaur Tracks," page 154.
^ Lockley and Meyer (2000); "Megalosaur Tracks," pages 152–153.
^ Lockley and Meyer (2000); "Megalosaur Tracks," page 153.
^ Lockley and Meyer (2000); "Theropod Tracks," pages 207–208.
^ Lockley and Meyer (2000); "Arctic Dinosaurs," page 220.
^ Lockley and Meyer (2000); "Arctic Dinosaurs," pages 220–222.
^ ^a ^b ^c Lockley and Meyer (2000); "Arctic Dinosaurs," page 222.
^ ^a ^b ^c Lockley and Meyer (2000); "A Miocene Menagerie," page 252.
^ ^a ^b Lockley and Meyer (2000); "France: The The Leveillon Sites," pages 106–107.
^ ^a ^b Lockley and Meyer (2000); "Archosaurs in the Air (Pterosaurian Giants)," page 189.
^ Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 251.
^ Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 58.
^ ^a ^b ^c Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 249.
^ Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," pages 251–252.
^ Lockley and Meyer (2000); "France: The The Leveillon Sites," page 107.
^ ^a ^b ^c Lockley and Meyer (2000); "Oligocene Act I: Tracking Ronzotherium, An Early Rhino," page 246.
^ Weishampel and Young (1996); "Leaksville Junction," pages 188–189.
^ ^a ^b ^c ^d ^e Lockley and Meyer (2000); "The World's Oldest Dinosaur Tracks: Fact, Fiction, and Controversy," page 68.
^ Lockley and Meyer (2000); "The World's Oldest Dinosaur Tracks: Fact, Fiction, and Controversy," page 67.
^ ^a ^b Lockley and Meyer (2000); "Dinosaurs in the Great Deltas of Yorkshire," page 134.
^ Lockley and Meyer (2000); "Further Along the Trail of the Elusive Ankylosaur," page 216.
^ Weishampel and Young (1996); "New York," page 172.
^ ^a ^b ^c Lockley and Meyer (2000); "Sauropods on the Rise: Germany, Iberia, and Switzerland," page 159.
^ Lockley and Meyer (2000); "The First Pareiasaur Trackway," page 47.
^ Lockley and Meyer (2000); "Mr. Pooley's Enigmatic Track Discovery," pages 143–144.
^ ^a ^b ^c ^d ^e Weishampel and Young (1996); "Culpeper," page 186.
^ ^a ^b ^c Lockley and Meyer (2000); "Social Sauropods," page 166.
^ ^a ^b Lockley and Meyer (2000); "Arctic Dinosaurs," page 224.
^ Lockley and Meyer (2000); "Welsh Dinosaurs at the Jolly Sailor Pub," page 80.
^ ^a ^b ^c Lockley and Meyer (2000); "Welsh Dinosaurs at the Jolly Sailor Pub," page 81.
^ Lockley and Meyer (2000); "Part II: Cruising the Carboniferous," page 32.
^ Lockley and Meyer (2000); "The Last of the Brontosaurs: Tracking Titanosaurs in the High Pyrenees," page 234.
^ Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 250.
^ Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," pages 249–251.
^ Lockley and Meyer (2000); "Theropod Tracks," page 207.
^ Lockley and Meyer (2000); "The Quiet Dawn: Paleocene-Eocene," page 244.
^ Weishampel and Young (1996); "Theropoda: Skeletons. Fires, and Footprints," page 114.
^ ^a ^b ^c Lockley and Meyer (2000); "Sauropod Tracks," page 209.
^ Lockley and Meyer (2000); "Tracks as Keys to Evolution and Locomotion," page 61.
^ Lockley and Meyer (2000); "Lizard Ancestors and Proto-Mammals with Hairy Feet," pages 65–67.
^ Lockley and Meyer (2000); "Lizard Ancestors and Proto-Mammals with Hairy Feet," page 67.
^ Lockley and Meyer (2000); "Turtles and Hopping Dinosaurs," page 177.
^ Lockley and Meyer (2000); "The March of the Prosauropods," pages 84–85.
^ Lockley and Meyer (2000); "The Last of the Brontosaurs: Tracking Titanosaurs in the High Pyrenees," pages 234–235.
^ Lockley and Meyer (2000); "The Last of the Brontosaurs: Tracking Titanosaurs in the High Pyrenees," page 235.
^ ^a ^b ^c ^d ^e ^f Lockley and Meyer (2000); "Ornithopod Tracks," page 211.
^ ^a ^b Lockley and Meyer (2000); "The German Summit Conference," page 44.
^ ^a ^b Lockley and Meyer (2000); "The German Summit Conference," page 45.
^ ^a ^b ^c ^d Lockley and Meyer (2000); "The First Ankylosaur Tracks," page 182.
^ Lockley and Meyer (2000); "The First Ankylosaur Tracks," pages 182–183.
^ Weishampel and Young (1996); "Ornithischia: Bones, Tracks, and Behavior," pages 93–94.
^ Weishampel and Young (1996); "Ornithischia: Bones, Tracks, and Behavior," page 95.
^ Weishampel and Young (1996); "Prosauropods: The Beginning of Big," page 100.
^ Lockley and Meyer (2000); "Stuck in the Mud: The Complete Trace of a Hammerhead Amphibian," page 47.
^ ^a ^b Lockley and Meyer (2000); "The World's Oldest Dinosaur Tracks: Fact, Fiction, and Controversy," page 69.
^ Lockley and Meyer (2000); "Oligocene Act I: Tracking Ronzotherium, An Early Rhino," pages 246–247.
^ Weishampel and Young (1996); "Culpeper," pages 186–188.
^ Weishampel and Young (1996); "Culpeper," page 188.
^ ^a ^b Weishampel and Young (1996); "Reading Area," page 184.
^ Lockley and Meyer (2000); "Turtles and Hopping Dinosaurs," pages 175–177.
^ Lockley and Meyer (2000); "Future Directions," page 71.
^ ^a ^b ^c ^d Lockley and Meyer (2000); "France: The Causses Region," page 111.
^ ^a ^b Lockley and Meyer (2000); "Tracks From Swedish Coal Mines and Railway Tunnels," page 115.
^ Lockley and Meyer (2000); "Tracking in the Holy Cross Mountains, Poland," page 117.
^ ^a ^b ^c Lockley and Meyer (2000); "The First Sauropods? Evidence From Italy," page 127.
^ ^a ^b Lockley and Meyer (2000); "Archosaurs in the Air (Pterosaurian Giants)," page 191.
^ Lockley and Meyer (2000); "Pliocene Interlude," page 256.
^ Lockley and Meyer (2000); "Baby Brontosaurs," page 162.
^ Lockley and Meyer (2000); "The Swiss Megatracksite," pages 169–171.
^ Lockley and Meyer (2000); "Iguanodon and Conan Doyle's Lost World," page 202.
^ Lockley and Meyer (2000); "Theropod Tracks," page 206.
^ ^a ^b ^c Lockley and Meyer (2000); "More Spoor of the Pterosaur," page 213.
^ ^a ^b Lockley and Meyer (2000); "Tracking Ancestors of the Cat: Miocene of Spain," page 255.
^ Weishampel and Young (1996); "Graterford," page 185.
^ Weishampel and Young (1996); "Graterford," pages 185–186.
^ Lockley and Meyer (2000); "Dinosaurs in the Great Deltas of Yorkshire," pages 135–136.
^ Lockley and Meyer (2000); "The First Iberian Sauropods," page 138.
^ Lockley and Meyer (2000); "The First Iberian Sauropods," page 139.
^ Lockley and Meyer (2000); "Sauropods on the Rise: Germany, Iberia, and Switzerland," pages 158–159.
^ Lockley and Meyer (2000); "Social Sauropods," pages 166–169.
^ Lockley and Meyer (2000); "Sex in the Footprint Bed," page 59.
^ Lockley and Meyer (2000); "The March of the Prosauropods," page 84.
^ ^a ^b Lockley and Meyer (2000); "Spoor of the Pterosaur," page 178.
^ Lockley and Meyer (2000); "Spoor of the Pterosaur," page 180.
^ Lockley and Meyer (2000); "Spoor of the Pterosaur," page 181.
^ Lockley and Meyer (2000); "A Miocene Menagerie," pages 252–253.
^ Lockley and Meyer (2000); "The First Sauropods? Evidence From Italy," page 129.
^ Lockley and Meyer (2000); "La Rioja," page 204.
^ Lockley and Meyer (2000); "Ornithopod Tracks," pages 209–211.

References

Lockley, Martin and Hunt, Adrian. Dinosaur Tracks of Western North America. Columbia University Press. 1999.
Lockley, M. G. and Meyer, C. A. 1999. Dinosaur Tracks and other fossil footprints of Europe. Columbia University Press. 323p
Weishampel, D.B. & L. Young. 1996. Dinosaurs of the East Coast. The Johns Hopkins University Press.

[weishampel-young-footprints-58-1] Weishampel and Young (1996); "Footprints in Stone," page 58.

[lockley-meyer-earliest-25-2] Lockley and Meyer (2000); "Earliest Discoveries," page 25.

[lockley-meyer-chirotherium-53-3] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 53.

[lockley-meyer-earliest-27-4] Lockley and Meyer (2000); "Earliest Discoveries," page 27.

[lockley-meyer-chirotherium-53-54-5] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," pages 53–54.

[lockley-meyer-chirotherium-54-6] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 54.

[weishampel-young-footprints-59-7] Weishampel and Young (1996); "Footprints in Stone," page 59.

[weishampel-young-footprints-59-60-8] Weishampel and Young (1996); "Footprints in Stone," pages 59–60.

[weishampel-young-footprints-60-9] Weishampel and Young (1996); "Footprints in Stone," page 60.

[weishampel-young-theropoda-113-10] Weishampel and Young (1996); "Theropoda: Skeletons. Fires, and Footprints," page 113.

[lockley-meyer-correct-195-11] Lockley and Meyer (2000); "1. What Are the Correct Ichnogenus and Species Names to Use for These Tracks?" page 195.

[lockley-meyer-rotliegendes-39-12] Lockley and Meyer (2000); "Rotliegendes: Permian Trackway Heaven," page 39.

[lockley-meyer-rotliegendes-38-13] Lockley and Meyer (2000); "Rotliegendes: Permian Trackway Heaven," page 38.

[lockley-meyer-holycross-118-14] Lockley and Meyer (2000); "Tracking in the Holy Cross Mountains, Poland," page 118.

[lockley-meyer-earliest-28-15] Lockley and Meyer (2000); "Earliest Discoveries," page 28.

[lockley-meyer-conandoyle-201-16] ^ ^a ^b ^c ^d ^e ^f Lockley and Meyer (2000); "Iguanodon and Conan Doyle's Lost World," page 201.

[weishampel-young-theropoda-98-17] Weishampel and Young (1996); "Theropoda: Tracking and Attacking in the Triassic," page 98.

[lockley-meyer-chirotherium-56-18] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 56.

[lockley-meyer-turtleshop-178-19] Lockley and Meyer (2000); "Turtles and Hopping Dinosaurs," page 178.

[weishampel-young-footprints-61-20] Weishampel and Young (1996); "Footprints in Stone," page 61.

[lockley-meyer-welshdino-79-21] Lockley and Meyer (2000); "Welsh Dinosaurs at the Jolly Sailor Pub," page 79.

[lockley-meyer-pooley-143-22] Lockley and Meyer (2000); "Mr. Pooley's Enigmatic Track Discovery," page 143.

[weishampel-young-more-62-23] Weishampel and Young (1996); "More Early Footprints," page 62.

[weishampel-young-more-63-24] ^ ^a ^b ^c ^d ^e ^f Weishampel and Young (1996); "More Early Footprints," page 63.

[lockley-meyer-yorkshire-133-25] Lockley and Meyer (2000); "Dinosaurs in the Great Deltas of Yorkshire," page 133.

[weishampel-young-more-62-63-26] Weishampel and Young (1996); "More Early Footprints," pages 62–63.

[lockley-meyer-miocene-255-27] Lockley and Meyer (2000); "A Miocene Menagerie," page 255.

[weishampel-young-more-61-28] Weishampel and Young (1996); "More Early Footprints," page 61.

[lockley-meyer-genusiguanodon-195-29] Lockley and Meyer (2000); "2. Were the Tracks Made by Representatives of the Genus Iguanodon Only, and If So, Which Species?" page 195.

[lockley-meyer-hominid-261-30] Lockley and Meyer (2000); "Subterranean Tracking: Hominid Ichnology," page 261.

[lockley-meyer-megalosaurtracks-152-31] Lockley and Meyer (2000); "Megalosaur Tracks," page 152.

[weishampel-young-virginia-105-32] Weishampel and Young (1996); "Virginia (Midland Formation)," page 105.

[lockley-meyer-chirotherium-56-57-33] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," pages 56–57.

[lockley-meyer-chirotherium-57-34] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 57.

[lockley-meyer-trackskey-60-35] Lockley and Meyer (2000); "Tracks as Keys to Evolution and Locomotion," page 60.

[lockley-meyer-hominid-262-36] Lockley and Meyer (2000); "Subterranean Tracking: Hominid Ichnology," page 262.

[lockley-meyer-actii-252-37] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 252.

[weishampel-young-more-64-38] ^ ^a ^b ^c ^d ^e ^f ^g Weishampel and Young (1996); "More Early Footprints," page 64.

[weishampel-young-more-66-39] Weishampel and Young (1996); "More Early Footprints," page 66.

[weishampel-young-more-64-66-40] Weishampel and Young (1996); "More Early Footprints," pages 64–66.

[lockley-meyer-coelurosaurichnus-95-41] Lockley and Meyer (2000); "Von Huene's Little Dinosaur Track: Coelurosaurichnus," page 95.

[lockley-meyer-hominid-260-42] Lockley and Meyer (2000); "Subterranean Tracking: Hominid Ichnology," page 260.

[lockley-meyer-actii-248-43] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 248.

[lockley-meyer-megalosaurtracks-154-44] Lockley and Meyer (2000); "Megalosaur Tracks," page 154.

[lockley-meyer-megalosaurtracks-152-153-45] Lockley and Meyer (2000); "Megalosaur Tracks," pages 152–153.

[lockley-meyer-megalosaurtracks-153-46] Lockley and Meyer (2000); "Megalosaur Tracks," page 153.

[lockley-meyer-theropod-207-208-47] Lockley and Meyer (2000); "Theropod Tracks," pages 207–208.

[lockley-meyer-arctic-220-48] Lockley and Meyer (2000); "Arctic Dinosaurs," page 220.

[lockley-meyer-arctic-220-222-49] Lockley and Meyer (2000); "Arctic Dinosaurs," pages 220–222.

[lockley-meyer-arctic-222-50] Lockley and Meyer (2000); "Arctic Dinosaurs," page 222.

[lockley-meyer-miocene-252-51] Lockley and Meyer (2000); "A Miocene Menagerie," page 252.

[lockley-meyer-france-106-107-52] Lockley and Meyer (2000); "France: The The Leveillon Sites," pages 106–107.

[lockley-meyer-air-189-53] Lockley and Meyer (2000); "Archosaurs in the Air (Pterosaurian Giants)," page 189.

[lockley-meyer-actii-251-54] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 251.

[lockley-meyer-chirotherium-58-55] Lockley and Meyer (2000); "The Story of Chirotherium: The Dawn of the Archosaurs," page 58.

[lockley-meyer-actii-249-56] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 249.

[lockley-meyer-actii-251-252-57] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," pages 251–252.

[lockley-meyer-france-107-58] Lockley and Meyer (2000); "France: The The Leveillon Sites," page 107.

[lockley-meyer-oligocene-246-59] Lockley and Meyer (2000); "Oligocene Act I: Tracking Ronzotherium, An Early Rhino," page 246.

[weishampel-young-leaksville-188-190-60] Weishampel and Young (1996); "Leaksville Junction," pages 188–189.

[lockley-meyer-worldsoldest-68-61] Lockley and Meyer (2000); "The World's Oldest Dinosaur Tracks: Fact, Fiction, and Controversy," page 68.

[lockley-meyer-worldsoldest-67-62] Lockley and Meyer (2000); "The World's Oldest Dinosaur Tracks: Fact, Fiction, and Controversy," page 67.

[lockley-meyer-yorkshire-134-63] Lockley and Meyer (2000); "Dinosaurs in the Great Deltas of Yorkshire," page 134.

[lockley-meyer-trail-216-64] Lockley and Meyer (2000); "Further Along the Trail of the Elusive Ankylosaur," page 216.

[weishampel-young-newyork-172-65] Weishampel and Young (1996); "New York," page 172.

[lockley-meyer-rise-159-66] Lockley and Meyer (2000); "Sauropods on the Rise: Germany, Iberia, and Switzerland," page 159.

[lockley-meyer-pareiasaur-47-67] Lockley and Meyer (2000); "The First Pareiasaur Trackway," page 47.

[lockley-meyer-pooley-143-144-68] Lockley and Meyer (2000); "Mr. Pooley's Enigmatic Track Discovery," pages 143–144.

[weishampel-young-culpeper-186-69] Weishampel and Young (1996); "Culpeper," page 186.

[lockley-meyer-social-166-70] Lockley and Meyer (2000); "Social Sauropods," page 166.

[lockley-meyer-arctic-224-71] Lockley and Meyer (2000); "Arctic Dinosaurs," page 224.

[lockley-meyer-welshdino-80-72] Lockley and Meyer (2000); "Welsh Dinosaurs at the Jolly Sailor Pub," page 80.

[lockley-meyer-welshdino-81-73] Lockley and Meyer (2000); "Welsh Dinosaurs at the Jolly Sailor Pub," page 81.

[lockley-meyer-cruising-32-74] Lockley and Meyer (2000); "Part II: Cruising the Carboniferous," page 32.

[lockley-meyer-last-234-75] Lockley and Meyer (2000); "The Last of the Brontosaurs: Tracking Titanosaurs in the High Pyrenees," page 234.

[lockley-meyer-actii-250-76] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," page 250.

[lockley-meyer-actii-249-251-77] Lockley and Meyer (2000); "Oligocene Act II: An Abundance of Waterfowl," pages 249–251.

[lockley-meyer-theropod-207-78] Lockley and Meyer (2000); "Theropod Tracks," page 207.

[lockley-meyer-quiet-244-79] Lockley and Meyer (2000); "The Quiet Dawn: Paleocene-Eocene," page 244.

[weishampel-young-theropoda-114-80] Weishampel and Young (1996); "Theropoda: Skeletons. Fires, and Footprints," page 114.

[lockley-meyer-sauropod-209-81] Lockley and Meyer (2000); "Sauropod Tracks," page 209.

[lockley-meyer-trackskey-61-82] Lockley and Meyer (2000); "Tracks as Keys to Evolution and Locomotion," page 61.

[lockley-meyer-lizard-proto-65-67-83] Lockley and Meyer (2000); "Lizard Ancestors and Proto-Mammals with Hairy Feet," pages 65–67.

[lockley-meyer-lizard-proto-67-84] Lockley and Meyer (2000); "Lizard Ancestors and Proto-Mammals with Hairy Feet," page 67.

[lockley-meyer-turtleshop-177-85] Lockley and Meyer (2000); "Turtles and Hopping Dinosaurs," page 177.

[lockley-meyer-marchprosauropods-84-85-86] Lockley and Meyer (2000); "The March of the Prosauropods," pages 84–85.

[lockley-meyer-last-234-235-87] Lockley and Meyer (2000); "The Last of the Brontosaurs: Tracking Titanosaurs in the High Pyrenees," pages 234–235.

[lockley-meyer-last-235-88] Lockley and Meyer (2000); "The Last of the Brontosaurs: Tracking Titanosaurs in the High Pyrenees," page 235.

[lockley-meyer-ornithopod-211-89] ^ ^a ^b ^c ^d ^e ^f Lockley and Meyer (2000); "Ornithopod Tracks," page 211.

[lockley-meyer-summit-44-90] Lockley and Meyer (2000); "The German Summit Conference," page 44.

[lockley-meyer-summit-45-91] Lockley and Meyer (2000); "The German Summit Conference," page 45.

[lockley-meyer-ankylo-182-92] Lockley and Meyer (2000); "The First Ankylosaur Tracks," page 182.

[lockley-meyer-ankylo-182-183-93] Lockley and Meyer (2000); "The First Ankylosaur Tracks," pages 182–183.

[weishampel-young-ornithischia-93-94-94] Weishampel and Young (1996); "Ornithischia: Bones, Tracks, and Behavior," pages 93–94.

[weishampel-young-ornithischia-95-95] Weishampel and Young (1996); "Ornithischia: Bones, Tracks, and Behavior," page 95.

[weishampel-young-prosauropods-100-96] Weishampel and Young (1996); "Prosauropods: The Beginning of Big," page 100.

[lockley-meyer-hammerhead-47-97] Lockley and Meyer (2000); "Stuck in the Mud: The Complete Trace of a Hammerhead Amphibian," page 47.

[lockley-meyer-worldsoldest-69-98] Lockley and Meyer (2000); "The World's Oldest Dinosaur Tracks: Fact, Fiction, and Controversy," page 69.

[lockley-meyer-oligocene-246-247-99] Lockley and Meyer (2000); "Oligocene Act I: Tracking Ronzotherium, An Early Rhino," pages 246–247.

[weishampel-young-culpeper-186-188-100] Weishampel and Young (1996); "Culpeper," pages 186–188.

[weishampel-young-culpeper-188-101] Weishampel and Young (1996); "Culpeper," page 188.

[weishampel-young-reading-184-102] Weishampel and Young (1996); "Reading Area," page 184.

[lockley-meyer-turtleshop-175-177-103] Lockley and Meyer (2000); "Turtles and Hopping Dinosaurs," pages 175–177.

[lockley-meyer-future-71-104] Lockley and Meyer (2000); "Future Directions," page 71.

[lockley-meyer-causses-111-105] Lockley and Meyer (2000); "France: The Causses Region," page 111.

[lockley-meyer-swedish-115-106] Lockley and Meyer (2000); "Tracks From Swedish Coal Mines and Railway Tunnels," page 115.

[lockley-meyer-holycross-117-107] Lockley and Meyer (2000); "Tracking in the Holy Cross Mountains, Poland," page 117.

[lockley-meyer-italy-127-108] Lockley and Meyer (2000); "The First Sauropods? Evidence From Italy," page 127.

[lockley-meyer-air-191-109] Lockley and Meyer (2000); "Archosaurs in the Air (Pterosaurian Giants)," page 191.

[lockley-meyer-pliocene-256-110] Lockley and Meyer (2000); "Pliocene Interlude," page 256.

[lockley-meyer-baby-162-111] Lockley and Meyer (2000); "Baby Brontosaurs," page 162.

[lockley-meyer-swiss-169-171-112] Lockley and Meyer (2000); "The Swiss Megatracksite," pages 169–171.

[lockley-meyer-conandoyle-202-113] Lockley and Meyer (2000); "Iguanodon and Conan Doyle's Lost World," page 202.

[lockley-meyer-theropod-206-114] Lockley and Meyer (2000); "Theropod Tracks," page 206.

[lockley-meyer-more-213-115] Lockley and Meyer (2000); "More Spoor of the Pterosaur," page 213.

[lockley-meyer-cat-255-116] Lockley and Meyer (2000); "Tracking Ancestors of the Cat: Miocene of Spain," page 255.

[weishampel-young-graterford-185-117] Weishampel and Young (1996); "Graterford," page 185.

[weishampel-young-graterford-185-186-118] Weishampel and Young (1996); "Graterford," pages 185–186.

[lockley-meyer-yorkshire-135-136-119] Lockley and Meyer (2000); "Dinosaurs in the Great Deltas of Yorkshire," pages 135–136.

[lockley-meyer-iberian-138-120] Lockley and Meyer (2000); "The First Iberian Sauropods," page 138.

[lockley-meyer-iberian-139-121] Lockley and Meyer (2000); "The First Iberian Sauropods," page 139.

[lockley-meyer-rise-158-159-122] Lockley and Meyer (2000); "Sauropods on the Rise: Germany, Iberia, and Switzerland," pages 158–159.

[lockley-meyer-social-166-169-123] Lockley and Meyer (2000); "Social Sauropods," pages 166–169.

[lockley-meyer-sex-59-124] Lockley and Meyer (2000); "Sex in the Footprint Bed," page 59.

[lockley-meyer-marchprosauropods-84-125] Lockley and Meyer (2000); "The March of the Prosauropods," page 84.

[lockley-meyer-ptero-178-126] Lockley and Meyer (2000); "Spoor of the Pterosaur," page 178.

[lockley-meyer-ptero-180-127] Lockley and Meyer (2000); "Spoor of the Pterosaur," page 180.

[lockley-meyer-ptero-181-128] Lockley and Meyer (2000); "Spoor of the Pterosaur," page 181.

[lockley-meyer-miocene-252-253-129] Lockley and Meyer (2000); "A Miocene Menagerie," pages 252–253.

[lockley-meyer-italy-129-130] Lockley and Meyer (2000); "The First Sauropods? Evidence From Italy," page 129.

[lockley-meyer-conandoyle-204-131] Lockley and Meyer (2000); "La Rioja," page 204.

[lockley-meyer-ornithopod-209-211-132] Lockley and Meyer (2000); "Ornithopod Tracks," pages 209–211.

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