User:Ixat totep/sandbox

Ambulacraria

Echinoderms are the sister group of the Hemichordata, with which they form the crown group Ambulacraria. Two taxa of uncertain placement, Vetulocystida and Yanjiahella, have each been proposed as either stem-group echinoderms or stem-group ambulacrarians. Vetulocystids have also been proposed as stem-group chordates, while Yanjiahella has also been proposed to be a stem-group hemichordate.

The Ambulacrarian context of the echinoderms is shown below, simplified from Li et al. 2023, with the possible ambulacrarian placements of the uncertian taxa shown with dashed lines and question marks:

Xenambulacraria	? Xenacoelomorpha Ambulacraria ? Vetulocystida †     Cambroernida †     ? Yanjiahella †     Ambulacraria Echinodermata ? Vetulocystida †     ? Yanjiahella †     Echinodermata     (crownward) (total group) Hemichordata ? Yanjiahella †     Hemichordata     (crownward) (total group) (crown group) (total group)
Chordata	? Vetulocystida †     Chordata     (crownward)
(total group)

Echinoderms

Material for Later

Asterozoa

Asterozoa Cantabrigiaster Villebrunaster Chinianaster Thoralaster Asterozoa Ophioxenikos Archegonaster Phragmactis Rhopalocoma Maydenia Eriniceaster Pradesura Eophiura Palaeura Protaster Encrinaster Ophiocantabria    Stenaster Urasterella Cnemidactis Platanaster Hudsonaster Petraster (crown group) (total group)

Somasteroidea Stenuroidea Ophiuroidea Asteroidea

Crinozoa: External phylogeny

Echinodermata	Ctenoimbricata † "Homalozoa" ? Ctenocystoidea † "Homalozoa" Cincta † Soluta †     ? Stylophora † Helicoplacoidea † Helicocystis † Edrioasteroidea † Eocrinoidea † Crinoidea Crinozoa Eleutherozoa

Echinodermata	? Arkarua † Helicoplacoidea † Edrioasteroidea † Blastozoa † (including Ctenocystoidea, Cincta, & Soluta) Crinozoa Stylophora † Crinoidea Eleutherozoa

Pelmatozoa and Eleutherozoa

F. A. Bather produced the earliest widely used classification of both fossil and extant echinoderms in 1900. His primary division was between Pelmatozoa and Eleutherozoa, both of which continue to be referenced in cladistic work despite being discarded by later taxonomies.

Pelmatozoa was originally defined by Leuckart for stemmed groups, but by 1900 had come to be used for all immobile forms. Eleutherozoa contained all mobile forms, which Bather believed had each descended from Edrioasteroidean groups at different times. In cladistic terms, this made Bather's Pelmatozoa paraphyletic with respect to a polyphyletic Eleutherozoa.

Ironically, cladistic approaches have consistently recovered Eleutherozoa as a monophyletic clade, a view now considered "uncontroversial." There is no such consensus regarding Pelmatozoa. Recent work restricts Pelmatozoa to its original scope of stemmed groups, but has differed as to whether it is monophyletic,, paraphyletic, ambiguous, or simply useful as an informal term describing body plans.

Homalozoa, Crinozoa, Echinozoa, and Asterozoa

In 1966 the Treatise on Invertebrate Paleontology, edited by Raymond Cecil Moore, rejected Bather's classification, replacing it with a new four-subphylum scheme that had been previously proposed by H. B. Fell. In addition to the obvious changes, the contents of Bather's Cystidea were distributed among the three Homalozoan classes and various Crinozoan classes, particularly Cystoidea and Eocrinoidea.

Artist's reconstruction of Camptostroma

Of these divisions, Camptostromatoidea is the only one not addressed by Sprinkle's subsequent revision (discussed below), although he notes that its sole genus, Camptostroma, is "strange." Subsequent research has placed Camptostroma as a basal Edrioasteroid.

Adding Blastozoa as a fifth subphylum

Difference between crinoid arms, which are extensions of the main body, and blastoid brachioles, which are not, had been observed for some time. In 1973, James Sprinkle concluded that enough fossil evidence of brachiole-bearing echinoderms had been assembled to justify placing them in their own phylum, Blastozoa, restricting Crinozoa to stalked forms with arms.

arms vs brachioles

James Sprinkle which added a fifth subphylum to the Treatise taxonomy in 1973. His later class-level taxonomy of the five subphyla was the most recent approach cited in an early cladistic re-assessment of the phylum.

Sprinkle split Blastozoa, defined by the presence of brachioles, out of Crinozoa, which he redefined as stalked taxa with arms. He also moved Edrioblastoidea to the Echinozoa, replaced Cystoidea by promoting its two orders, Rhombifera and Diploporita, to class level, and similarly replaced Stellaroidea by promoting two of its sublasses, Asteroidea and Ophiuroidea. Finally, he demoted Lepidocystoidea, moving it under Eocrinoidea, and dropped Camptostromatoidea as a class without explicitly reassigning the "strange" genus Camptostroma.

In addition to the obvious re-allocation of formerly Crinozoan classes to Blastozoa and (in the case of Edrioblastoidea) Echinozoa, Sprinkle made the following changes:

• Demoted Lepidocystoidea and placed it under Eocrinoidea
• Demoted Camptostromatoidea without placing its "strange" sole genus, Camptostroma, into another class
• Adopted Christopher R. C. Paul's 1968 raising of Rhombifera and Diploporita to class level, replacing Cystoidea which had contained only those two taxa as orders
• Adopted the replacement of Stelleroidea with two of its three sub-classes, Asteroidea and Ophiuroidea, promoted to class level

The division of classes between Crinozoa and Blastozoa, and the relationship of the subphyla to each other, remains a substantial point of debate. Some workers have found Blastozoa to be paraphyletic with respect to Crinozoa, or polyphyletic, as illustrated by cladograms in the next section.

Echinozoa and Asterozoa have been accepted as monophyletic sub-taxa of Eleutherozoa, although a few workers continue to support the clade Cryptosyringida, uniting Ophiuroida and Echinozoa as the sister group of the Asteroidea.

Under cladistic approaches, Eleutherozoa and Asterozoa have been proven to be monophyletic as defined above, as have Crinoidea and a reduced Echinozoa limited to Echinoidea, Holothuroidea, and Ophiocistioidea.

While each class within the Homolozoa is still thought to be monophyletic, the subphylum itself is either polyphyletic or paraphyletic. The contents, relationships, and monophyly of Blastozoa, Crinozoa (beyond Crinoidea), Pelmatozoa (often narrowed to include only stemmed classes), their constituent classes, and the classes excluded from the narrowed Echinozoa, remain contentious.

probably not

Bather also provided a diagram that, together with his statement that "even if all Eleutherozoa descended from one class of Pelmatozoa, they did so at widely differing periods" and in a specific order, is roughly equivalent to the following cladogram:

Pelmatozoa	Cystidea† (Homalozoans, Eocrinoids, Paracrinoids, Cystoids) Blastoidea† Crinoidea some Edrioasteroids† Edrioasteroidea Holothuroidea some Edrioasteroids† Echinoidea some Edrioasteroids†   Stelleroidea Eleutherozoa

This shows Pelmatozoa and Edrioasteroidea as paraphyletic with respect to a polyphyletic Eleutherozoa

Internal phylogeny

Echino‑	Crinoidea (feather stars) Echinozoa Holothuroidea sea cucumbers Echinoidea sea urchins, etc Asterozoa Ophiuroidea brittle & basket stars Asteroidea starfish
dermata

Fossil history

David et. al 2000

The following cladogram is based on David & Mooi (1999) and David, Lefebvre, Mooi, and Parsley (2000):

Echinodermata	? Arkarua† Helicoplacoidea† Edrioasteroidea† Blastozoa† Lepidocystiodea† Eocrinoidea† some Eocrinoids† some Eocrinoids† some Eocrinoids† Homostelea† (Cincta) Ctenocystoids† Homoiostelea† (Soluta) Diploporita† Cystoidea† Rhombifera† Blastoidea† Crinozoa Crinoidea Stylophora† Eleutherozoa Asterozoa Ophiuroidea Asteroidea Echinozoa Echinoidea Ophiocistioidea† Holothuroidea

Notes:

• Parablastoidea and Paracrinoidea are stated to be part of Blastozoa, but are not placed on the cladogram
• Edrioblastoidea is not mentioned, and while the sole genus Camptostroma of Camptostromatoidea is mentioned, it is not explicitly associated with a class
• Helicocystis, Ctenoimbricata, and Yanjiahella had not yet been discovered (see next cladogram for their significance)
• Pelmatozoa is shown to be paraphyletic

Zamora & Smith 2024

The following cladogram is based on Rahman & Zamora (2024),, using class names from the cladogram's caption, plus additional subphylum names from the article text. A dashed line and a question mark indicate uncertain placement:

Echinodermata	Ctenoimbricata† Ctenocystoidea†     Cincta† (Homostelea)         Soluta† (Homoiostelea) Stylophora† ?     Helicoplacoidea†     Helicocystis†     Eocrinoidea† Edrioasteroidea† Crinoidea Eleutherozoa Echinozoa Echinoidea Holothuroidea Asterozoa Asteroidea Ophiuroidea

Notes

• Ophiocistioidea is not addressed by this paper, see the previous cladogram above for a typical placement
• Non-eocrinoid blastozoans are mentioned but not placed on the cladogram
• Arkarua is not considered an echinoderm and is intentionally omitted

Bather 1900

Pelmatozoa

Cystidea† some Eocrinoids† some Eocrinoids† + some Cornute Stylophorans† Homostelea† (Cincta) + some Cornute Stylophorans† Mitrate Stylophorans† Homoiostelea† (Soluta) some Diploporitans† Cystoidea† some Diploporitans† Rhombifera† Blastoidea Crinoidea Edrioasteroidea some Edrioasteroids Eleutherozoa Holothuroidea some Edrioasteroids Echinoidea some Edrioasteroids Stelleroidea Asteroidea Ophiuroidea

Smith 1984

Smith revived the name "Cystoidea" in place of Sprinkle's "Blastozoa", including the traditional Eocrinoidea, Rhombifera, Diploporita, Blastoidea, and Paracrinoidea within it.

	"Carpoids" (Homalozoa)
Echinodermata (total)	Helicoplacoidea† Echinodermata (crown) Camptostroma† Pelmatozoa Cystoidea† (Blastozoa) Crinoidea Eleutherozoa Stromatocystites Edrioasteroidea† Asteroidea Cryptosyringida Ophiuroidea Echinozoa Echinoidea Holothuroidea

Existing Text

The oldest candidate echinoderm fossil is Arkarua from the Precambrian of Australia. These fossils are disc-like, with radial ridges on the rim and a five-pointed central depression marked with radial lines. However, the fossils have no stereom or internal structure indicating a water vascular system, so they cannot be conclusively identified.

The first universally accepted echinoderms appear in the Lower Cambrian period; asterozoans appeared in the Ordovician, while the crinoids were a dominant group in the Paleozoic. Echinoderms left behind an extensive fossil record. It is hypothesised that the ancestor of all echinoderms was a simple, motile, bilaterally symmetrical animal with a mouth, gut and anus. This ancestral organism adopted an attached mode of life with suspension feeding, and developed radial symmetry. Even so, the larvae of all echinoderms are bilaterally symmetrical, and all develop radial symmetry at metamorphosis. Like their ancestor, the starfish and crinoids still attach themselves to the seabed while changing to their adult form.

The first echinoderms were non-motile, but evolved into animals able to move freely. These soon developed endoskeletal plates with stereom structure, and external ciliary grooves for feeding. The Paleozoic echinoderms were globular, attached to the substrate and were orientated with their oral surfaces facing upwards. These early echinoderms had ambulacral grooves extending down the side of the body, fringed on either side by brachioles, like the pinnules of a modern crinoid. Eventually, except for the crinoids, all the classes of echinoderms reversed their orientation to become mouth-downward. Before this happened, the podia probably had a feeding function, as they do in the crinoids today. The locomotor function of the podia came later, when the re-orientation of the mouth brought the podia into contact with the substrate for the first time.

Further information: Dibrachicystis

• 
  Early echinoderms Ctenoimbricata, Ctenocystis, Gogia, Protocintus and Rhenocystis
• 
  The Ordovician cystoid Echinosphaerites from northeastern Estonia
• 
  Fossil crinoid crowns
• 
  Calyx of Hyperoblastus, a blastoid from the Devonian of Wisconsin

Alternative echinoderm trees

Rahman & Zamora 2024 genera

Ambulacraria	? Yanjiahella† Hemichordata ? Yanjiahella† Echinodermata ? Yanjiahella† Ctenoimbricata† Ctenocystoids† Ctenocystis† Courtessolea† Cinctans† Protocinctus† Solutes† Coleicarpus† ? Stylophorans† Ceratocystis Helicoplacoids† Helicoplacus† Helicocystis† Eocrinoids† Gogia† Edrioasteroids† Camptostroma† Crinoids Eleutherozoans Echinozoans Echinoidea Holothuroidea Asterozoa Asteroidea Ophiuroidea

Yanjiahella

2019-02-15-a A stem group echinoderm from the basal Cambrian of China and the origins of Ambulacraria.pdf

Echinodermata	Yanjiahella† Ctenocystoids† Cinctans† Solutes† Helicoplacus† Camptostroma† Eleutherozoans Stromatocystites† Kinzercystis† Blastozoans† Gogia† Akadocrinus† Pleurocystites† Ubaghsicystis† Macrocystella† Aethocrinus†

• Up to Helicoplacus is the stem group
• Aethocrinus represents Crinozoans
• Pelmatozoans was labled spanning Blastozoans and Crinozoans

Ridiculous chart

Notable Linnaean taxonomies of phylum Echinodermata

Bather, 1900	Moore, 1966	Sprinkle, 1980
Phylum Echinoderma [sic] Grade Pelmatozoa     Class Cystidea† Class Cystidea† Class Cystidea†     Class Crinoidea Class Cystidea† Class Cystidea† Class Cystidea† Class Cystidea†   Class Blastoidea†         Class Edrioasteroidea†         Grade Eleutherozoa Class Echinoidea Class Holothuroidea   Class Stelleroidea Class Stelleroidea†	Phylum Echinodermata   Subphylum Homalozoa†   Class Stylophora† Class Homostelea† Class Homoiostelea† Subphylum Crinozoa Class Paracrinoidea† Class Crinoidea Class Eocrinoidea† Class Lepidocystoidea† Class Cystoidea† Class Cystoidea† Class Parablastoidea† Class Blastoidea†     Class Edrioblastoidea† Subphylum Echinozoa Class Edrioasteroidea† Class Camptostromatoidea† Class Helicoplacoidea† Class Cyclocystoidea† Class Ophiocistioidea†   Class Echinoidea Class Holothuroidea Subphylum Asterozoa Class Stelleroidea Class Stelleroidea†	Phylum Echinodermata   Subphylum Homalozoat Class Ctenocystoidea† Class Stylophora† Class Homostelea† Class Homoiostelea† Subphylum Crinozoa Class Paracrinoideat Class Crinoidea Subphylum Blastozoa† Class Eocrinoidea† Class Eocrinoidea† Class Rhombifera† Class Diploporita† Class Parablastoideat Class Blastoidea† Subphylum Echinozoa Class Edrioblastoidea†   Class Edrioasteroidea† Class Edrioblasteroidea† Class Helicoplacoideat Class Cyclocystoidea† Class Ophiocistioidea†   Class Echinoidea Class Holothuroidea Subphylum Asterozoa Class Asteroidea Class Ophiuroidea

Linnean Taxonomy Wide

Bather, 1900	various authors, 1966-67	Ubaghs, 1978	Sprinkle, 1980
Phylum Echinoderma [sic] Grade Pelmatozoa Class Cystidea† Class Blastoidea† Class Crinoidea Class Edrioasteroidea† Grade Eleutherozoa Class Holothuroidea Class Stelleroidea Class Echinoidea	Phylum Echinodermata Subphylum Homalozoa† Class Stylophora† Class Homostelea† Class Homoiostelea† Subphylum Crinozoa Class Lepidocystoidea† Class Eocrinoidea† Class Cystoidea† Class Edrioblastoidea† Class Parablastoidea† Class Blastoidea† Class Paracrinoidea† Class Crinoidea Subphylum Asterozoa Class Stelleroidea Subphylum Echinozoa Class Helicoplacoidea† Class Camptostromatoidea† Class Edrioasteroidea† Class Cyclocystoidea† Class Ophiocystioidea† Class Echinoidea Class Holothuroidea	Phylum Echinodermata Subphylum Homalozoa† Class Ctenocystoidea† Class Stylophora† Class Homostelea† Class Homoiostelea† Subphylum Crinozoa Class Eocrinoidea† Class Rhombifera† Class Diploporita† Class Parablastoidea† Class Blastoidea† Class Paracrinoidea† Class Crinoidea Subphylum Asterozoa Class Stelleroidea Subphylum Echinozoa Class Helicoplacoideat Class Camptostromatoidea† Class Edrioasteroidea† Class Edrioblastoidea† Class Cyclocystoidea† Class Ophiocystioidea† Class Echinoidea Class Holothuroidea	Phylum Echinodermata Subphylum Homalozoat Class Ctenocystoidea† Class Stylophora† Class Homostelea† Class Homoiostelea† Subphylum Blastozoa† Class Eocrinoidea† Class Rhombifera† Class Diploporita† Class Parablastoideat Class Blastoidea† Subphylum Crinozoa Class Paracrinoideat Class Crinoidea Subphylum Asterozoa Class Asteroidea Class Ophiuroidea Subphylum Echinozoa Class Helicoplacoideat Class Edrioasteroidea† Class Edrioblastoidea† Class Cyclocystoidea† Class Ophiocystioidea† Class Echinoidea Class Holothuroidea

Bather's Cystidea included taxa later assigned to Homalozoa, Eocrinoidea, and Cystoidea. The 1966-67 Cystoidea consisted of two orders, Rhombifera and Diplorita, that were promoted to classes in Sprinkle's phylogeny. Sprinkle split Blastozoa (taxa with brachioles) from Crinozoa (taxa with true arms), as well as demoting Lepidocystoidea and Camptostromatoidea, placing them under Eocrinoidea and Edrioasteroidea, respectively. MOAR NEEDED

Works cited

• Ausich, William I.; Kammer, Thomas W.; Rhenberg, Elizabeth C.; Wright, David F. (October 2015). "Early phylogeny of crinoids within the pelmatozoan clade". Paleontolgy. 58 (6): 937–952. doi:10.1111/pala.12204.
• Bather, F. A. (1900). "Chapter VIII: General Description of the Echinoderma". In Lankester, E. Ray (ed.). A Treatise on Zoology, Part III: The Echinoderma. London: Adam & Charles Black. pp. 1–37. doi:10.1080/00222930008678384.
• Blake, Daniel B.; Hotchkiss, Frederick H.C. (2022). "Origin of the subphylum Asterozoa and redescription of a Moroccan Ordovician somasteroid". Geobios. 72–73: 22–36. doi:10.1016/j.geobios.2022.07.002.
• Brusca, Richard C.; Moore, Wendy; Shuster, Stephen M. (2016). Invertebrates (3rd ed.). Sunderland, Massachusetts. ISBN 978-1-60535-375-3. OCLC 928750550.{{cite book}}: CS1 maint: location missing publisher (link)
• Conway Morris, Simon; Halgedahl, Susan L.; Selden, Paul; Jarrard, Richard D. (2015). "Rare primitive deuterostomes from the Cambrian (Series 3) of Utah" (PDF). Journal of Paleontology. 89 (4): 631–636. doi:10.1017/jpa.2015.40.
• David, Bruno; Lefebvre, Bertrand; Mooi, Rich; Parsley, Ronald (December 2000). "Are homalozoans echinoderms? An answer from the extraxial-axial theory". Paleobiology. 26 (4): 520–555. doi:10.1666/0094-8373(2000)026<0529:AHEAAF>2.0.CO;2.
• David, Bruno; Mooi, Rich (1998). "Major events in the evolution of echinoderms viewed by the light of embryology". Proceedings of the Ninth International Echinoderm Conference: San Francisco, California, USA, 5-9 August, 1996. Rotterdam: A.A. Balkema. pp. 21–28.
• David, Bruno; Mooi, Rich (January 1999). "Contributions of the extraxial-axial theory to understanding the echinoderms". Bulletin de la Societe Geologique de France. 170 (1): 91–101. Retrieved 28 October 2024.
• Deline, Bradley; Thompson, Jeffrey R.; Smith, Nicholas S.; Zamora, Samuel; Rahman, Imran A.; Sheffield, Sarah L.; Ausich, William I.; Kammer, Thomas W.; Sumrall, Colin D. (2020). "Evolution and development at the origin of a phylum". Current Biology. 30: 1672–1679. doi:10.1016/j.cub.2020.02.054.
• Dorit, R. L.; Walker, W. F.; Barnes, R. D. (1991). Zoology, International edition. Saunders College Publishing. ISBN 978-0-03-030504-7.
• Durham, J. W. (1 September 1966). "Camptostroma, an Early Cambrian Supposed Scyphozoan, Referable to Echinodermata". Journal of Paleontology. 40 (5): 1009–1255. ISSN 0022-3360. JSTOR 1301996.
• Durham, J. Wyatt; Caster, Kenneth E. (1966). "Helicoplacoids". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. University of Kansas Press. pp. U131–U136. Retrieved 28 October 2024.
• Durham, J. Wyatt (1967). "Addendum: Camptostromatoids". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part S: Echinodermata 1. Vol. 1. University of Kansas Press. pp. S627–S631. Retrieved 29 October 2024.
• Escriva, Hector; Reich, Adrian; Dunn, Casey; Akasaka, Koji; Wessel, Gary (2015). "Phylogenomic Analyses of Echinodermata Support the Sister Groups of Asterozoa and Echinozoa". PLOS ONE. 10 (3): e0119627. Bibcode:2015PLoSO..1019627R. doi:10.1371/journal.pone.0119627. PMC 4368666. PMID 25794146.
• Guensburg, Thomas E.; Blake, Daniel B.; Sprinkle, James; Mooi, Rich (2016). "Crinoid ancestry without blastozoans". Acta Paleontologica Polemica. 61 (2): 253–266. doi:10.4202/app.00211.2015.
• Guensburg, Thomas E.; Sprinkle, James (1994). Revised phylogeny and functional interpretation of the Edrioasteroidea based on new taxa from the Early and Middle Ordovician of western Utah. Fieldiana. Geology. Vol. New Series, No. 29. Chicago: Field Museum of Natural History. doi:10.5962/bhl.title.3313.
• Guensburg, Thomas E.; Sprinkle, James; Mooi, Rich; Lefebvre, Bertrand; David, Bruno; Roux, Michael; Derstler, Kraig (2020). "Athenacrinus n. gen. and other early echinoderm taxa inform crinoid origin and arm evolution". Journal of Paleontology. 94 (2): 311–333. doi:10.1017/jpa.2019.87.
• Hunter, Aaron W.; Ortega-Hernández, Javier (2020). "A new somasteroid from the Fezouata Lagerstätte in Morocco and the Early Ordovician origin of Asterozoa". Biology Letters. 17. doi:10.1098/rsbl.2020.0809.
• Kesling, Robert V. (1966). "Cyclocystoids". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. University of Kansas Press. pp. U188–U210. Retrieved 28 October 2024.
• Li, Yujing; Dunn, Frances S.; Murdock, Duncan J.E.; Guo, Jin; Rahman, Imran A.; Cong, Peiyun (May 10, 2023). "Cambrian stem-group ambulacrarians and the nature of the ancestral deuterostome". Current Biology. doi:10.1016/j.cub.2023.04.048. PMID 37167976. S2CID 258592223. Retrieved 11 May 2023.
• Limbeck, Maggie R.; Bauer, Jennifer E.; Deline, Bradley; Sumrall, Colin D. "Initial quantitative assessment of the enigmatic clade Paracrinoidea (Echinodermata)". Paleontology. 67 (3). doi:10.1111/pala.12695.
• McCormick, Lavon; Moore, R. C. (1966). "Echinoids: Outline of Classification". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. University of Kansas Press. pp. U295–U297. Retrieved 28 October 2024.
• Mooi, Rich; David, Bruno (June 2000). "What a new model of skeletal homologies tells us about asteroid evolution". American Zoologist. 40 (3): 326–339. doi:10.1668/0003-1569(2000)040[0326:WANMOS]2.0.CO;2.
• Moore, Raymond C. (1966). "Introduction". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. Vol. 1. University of Kansas Press. pp. U1–U3. Retrieved 28 October 2024.
• Mussini, G.; Smith, M. P.; Vinther, J.; Rahman, I. A.; Murdock, D. J. E.; Harper, D. A. T.; Dunn, F. S. (2024). "A new interpretation of Pikaia reveals the origins of the chordate body plan". Current Biology. 34 (13): 2980-2989.e2. doi:10.1016/j.cub.2024.05.026.
• Nanglu, Karma; Cole, Selina R.; Wright, David F.; Souto, Camilla (2023). "Worms and gills, plates and spines: the evolutionary origins and incredible disparity of deuterostomes revealed by fossils, genes, and development". Biological Reviews. 98: 316–351. doi:10.1111/brv.12908.
• Paul, Christopher R. C.; Lefebvre, Bertrand; Nohejlová, Martina; Zamora, Samuel (2024). "Rhombifera Barrande, 1867, and the origin of the Blastoidea (Echinodermata, Blastozoa)". Spanish Journal of Palaeontology. 39. doi:10.7203/sjp.28729.
• Paul, C. R. C.; Smith, A. B. (November 1984). "The early radiation and phylogeny of echinoderms". Biological Reviews. 59 (4): 443–481. doi:10.1111/j.1469-185X.1984.tb00411.x.
• Rahman, Imran A.; Zamora, Samuel (July 2024). "Origin and early evolution of echinoderms". Annual Review of Earth and Planetary Sciences. 52: 295–320. doi:10.1146/annurev-earth-031621-113343.
• Regnéll, Gerhard (1966). "Edrioasteroids". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. University of Kansas Press. pp. U136–U173. Retrieved 28 October 2024.
• Reich, Mike; Sprinkle, James; Lefebvre, Bertrand; Rössner, Gertrud E.; Zamora, Samuel (2017). "The first Ordovician cyclocystoid (Echinodermata) from Gondwana and its morphology, paleoecology, taphonomy, and paleogeography". Journal of Paleontology. 91 (4): 734–754. doi:10.1017/jpa.2017.7.
• Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology (7th ed.). Cengage Learning. ISBN 81-315-0104-3.{{cite book}}: CS1 maint: multiple names: authors list (link)
• Sheffield, Sarah L.; Sumrall, Colin D. (2019a). "The phylogeny of the Diploporita: a polyphyletic assemblage of blastozoan echinoderms". Journal of Paleontology. 93 (4): 740–752. doi:10.1017/jpa.2019.2.
• Sheffield, Sarah L.; Sumrall, Colin D. (2019b). "A re-interpretation of the ambulacral system of eumorphocystis (blastozoa, echinodermata) and its bearing on the evolution of early crinoids". Paleontology. 62 (1): 163–173. doi:10.1111/pala.12396.
• Shu, D.-G.; Conway Morris, S.; Han, J.; Zhang, Z.-F.; Liu, J.-N. (2004). "Ancestral echinoderms from the Chengjiang deposits of China". Nature. 430 (6998): 422–428. Bibcode:2004Natur.430..422S. doi:10.1038/nature02648. PMID 15269760. S2CID 4421182.
• Smith, Andrew B. (1984). "Classification of the Echinodermata" (PDF). Paleontology. 27 (3): 431–459. Retrieved 28 October 2024.
• Spencer, W. K.; Wright, C. W. (1966). "Asterozoans". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. University of Kansas Press. pp. U4–U107. Retrieved 28 October 2024.
• Sprinkle, James (1973). "Morphology and evolution of blastozoan echinoderms". Special Publication of the Museum of Comparative Zoology, Harvard University. Retrieved 29 October 2024.
• Sprinkle, James (1980a). "Origin of blastoids: new look at an old problem (Abst.)". Geological Society of America Abstracts with Programs. 12 (7): 528.
• Sprinkle, J. (1980b). "An Overview of the Fossil Record". Notes for a Short Course: Studies in Geology. 3: 15–26. doi:10.1017/S0271164800000063.
• Sumrall, Colin D.; Sprinkle, James (1998). "Phylogenetic analysis of living Echinodermata based on primitive fossil taxa". Proceedings of the Ninth International Echinoderm Conference: San Francisco, California, USA, 5-9 August, 1996. Rotterdam: A.A. Balkema. pp. 81–87.
• Telford, M. J.; Lowe, C. J.; Cameron, C. B.; Ortega-Martinez, O.; Aronowicz, J.; Oliveri, P.; Copley, R. R. (2014). "Phylogenomic analysis of echinoderm class relationships supports Asterozoa". Proceedings of the Royal Society B: Biological Sciences. 281 (1786): 20140479. doi:10.1098/rspb.2014.0479. PMC 4046411. PMID 24850925.
• Topper, Timothy P.; Guo, Junfeng; Clausen, Sébastien; Skovsted, Christian B.; Zhang, Zhifei (2019-03-25). "A stem group echinoderm from the basal Cambrian of China and the origins of Ambulacraria". Nature Communications. 10 (1): 1366. Bibcode:2019NatCo..10.1366T. doi:10.1038/s41467-019-09059-3. ISSN 2041-1723. PMC 6433856. PMID 30911013.
• Topper, Timothy P.; Guo, Junfeng; Clausen, Sébastien; Skovsted, Christian B.; Zhang, Zhifei. "Reply to 'Re-evaluating the phylogenetic position of the enigmatic early Cambrian deuterostome Yanjiahella". Nature Communications. 11 (1): 1287. doi:10.1038/s41467-020-14922-9.
• Ubaghs, Georges (1966). "Ophiocistioids". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part U: Echinodermata 3. University of Kansas Press. pp. U174–U188. Retrieved 28 October 2024.
• Ubaghs, Georges (1967). "General Characters of Echinodermata". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part S: Echinodermata 1. Vol. 1. University of Kansas Press. pp. S3–S60. Retrieved 29 October 2024.
• Ubaghs, Georges (1978). "Classification of the Echinoderms". In Moore, Raymond C. (ed.). Treatise on Invertebrate Paleontology, Part T: Echinodermata 2. Vol. 1. University of Kansas Press. pp. T359–T367. Retrieved 29 October 2024.
• Zamora, Samuel; Rahman, Imran A.; Sumrall, Colin D.; Gibson, Adam P.; Thompson, Jeffrey R. (2022). "Cambrian edrioasteroid reveals new mechanism for secondary reduction of the skeleton in echinoderms". Proceedings of the Royal Society B. 289. doi:10.1098/rspb.2021.2733.
• Zamora, Samuel; Wright, David F.; Mooi, Rich; Lefebvre, Bertrand; Guensburg, Thomas E.; Gorzelak, Przemysław; David, Bruno; Sumrall, Colin D.; Cole, Selina R.; Hunter, Aaron W.; Sprinkle, James (2020-03-09). "Re-evaluating the phylogenetic position of the enigmatic early Cambrian deuterostome Yanjiahella". Nature Communications. 11 (1): 1286. Bibcode:2020NatCo..11.1286Z. doi:10.1038/s41467-020-14920-x. ISSN 2041-1723. PMC 7063041. PMID 32152310.
• Zamora, Samuel; Deline, Bradley; Álvaro, J. Javier; Rahman, Imran A. (2017). "The Cambrian Substrate Revolution and the early evolution of attachment in suspension-feeding echinoderms". Earth-Science Reviews. 171: 478–491. doi:10.1016/j.earscirev.2017.06.018.

Potential specific citations

• Volume S phylogeny
• Volume S naming
• Tribrachidium heraldicum considered and dismisssed
• Arkarua adami rejected as true 5-fold symmetry is not seen in the Echinoderm fossil record until the emergence of Eleutherozoa in the Ordovician (or _possibly_ late Cambrian), and no other Echinoderm features are present
• Blastozoa to be paraphyletic with respect to Crinoidea
• Blastozoa (under the name Cystoidea) and Crinoidea to form a monophyletic slimmed-down Pelmatozoa
• Edrioasteroidea to be paraphyletic with respect to a clade consisting of Blastozoa and Crinoidea
• Rhombifera:Dichoporita:Glyptocystitoidea paraphyletic to Blastoidea, in polytomy with Rhombifera (Rhombiferdae), which is sister to Dichoporita:Hemicosmitoidea, which is sister to the rest of Glyptocystitoidea, with basal Glyptocystitida/Dichoporita:Sanducystis in polytome with it and several Eocrinoids
• Diploporita polyphyletic with Glyptosphaeritida paraphyletic w.r.t. Sphaeronitida, Rhombifera, Crinoidea, Paracrinoidea, Parablastoidea, and Diploporita:Asteroblastidae; Rhombifera paraphyletic to Coronoidea; Sphaeronitida monophyletic if includes former Glyptosphaeritidan Eucystis angelini; Holocystitidae monophyletic within Sphaeronitida

Relationships

Note that Smith (1984) uses "Cystoidea" in place of "Blastozoa", but makes the equivalence explicit.

Pelmatozoa

Crinozoa

Blastozoa

Rhombifera

Diploporita

Coronoidea

Lepidocystiodea

Eocrinoidea

Paracrinoidea

Crinoidea

Blastoidea

Parablastoidea

Edrioblastoidea

Edrioasteroidea

Stromatocystitoidea

Camptostromatoidea

Cyclocystoidea

Ophiocistioidea

Holothuroidea

Echinoidea

Echinozoa

Ophiuroidea

Stenuroidea

Asteroidea

Somasteroidea

Asterozoa

Eleutherozoa

Helicocystiodea

Helicoplacoidea

Ctenoimbricatiodea

Ctenocystoidea

Cincta

Soluta

Stylophora

Homalozoa

Pelmatozoa

monophyletic: 1984

parent: 1984

parent: 1984

polytomy: 1984

polytomy: 1984

Crinozoa

Blastozoa

child: 1984

Rhombifera

sister: 2019

Diploporita

polyphyletic: 2019

paraphyletic: 2019

Coronoidea

sister: 2019

Lepidocystoidea

Eocrinoidea

Paracrinoidea

Crinoidea

child: 1984

excluded: 2019

Blastoidea

Parablastoidea

Edrioblastoidea

Edrioasteroidea

monophyletic: 1984

child: 1984

paraphyletic: 1984

Stromatocystitoidea

paraphyletic: 1984

Camptostromatoidea

polytomy: 1984

X

polytomy: 1984

Cyclocystoidea

descendant: 1984

monophyletic: 1984

Ophiocistioidea

paraphyletic: 1984

Holothuroidea

stem: 1984

Echinoidea

Echinozoa

Ophiuroidea

Stenuroidea

Asteroidea

Somasteroidea

Asterozoa

Eleutherozoa

polytomy: 1984

scion: 1984

polytomy: 1984

monophyletic: 1984

Helicocystoidea

Helicoplacoidea

Ctenoimbricatoidea

Ctenocystoidea

Cincta

Soluta

Stylophora

Homalozoa

plesion: 1984