User:NoahMcGoff/Cephalochordates Group Assignment

Week 13

Introduction

A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called Amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide. With the presence of a notochord, adult amphioxus are able to swim and tolerate the tides of coastal environments, but they are most likely to be found within the sediment of these communities.

Cephalochordates are segmented marine animals that possess elongated bodies containing a notochord that extends the length of the body from head to tail. They are only a few centimeters in length and due to their lack of a mineralized skeleton, their presence in the fossil record is minimal. A few fossils have been found such as the Burgess Shale of British Columbia which contained the fossils of Pikaia, and the Yunnanozoon fossil which also dates back to the Cambrian period.

Feeding

Cephalochordate feeding structures

Cephalochordates have developed a filter feeding system, called the oral hood, that serves as the entrance for incoming food particles. The free edge of the oral hood contains Buccal cirri, small filament-like projections, that assist in sifting out larger food particles before they enter the buccal cavity. These projections are chemoreceptors that stimulate the epithelial cilia lining inside the walls of the oral hood to bring food particles into the mouth. The coordinated movement of several ciliated tracts help facilitate food ingestion through a rotating motion that is similar to that of a wheel, causing cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before transferring to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transported to the gut while excess water is pumped out of the pharynx through the pharyngeal slits. The excess water excretes from the body using a single atriopore of the atrium.

Morphology

Cephalochordate lancelet Anatomy

The general cephalochordate body plan is considered to be a dorsoventrally flipped version of earlier deuterostomes. Gene-expression studies on embryonic patterning suggest that body axis formation has inverted somewhere between hemichordates and chordates, where the ventral formation of body structures in earlier hemichordates is observed to be dorsal in cephalochordates.

Studies have shown that there is a correlation between the branchiomeric muscles of vertebrates with the orobranchial muscles within the pharynx of chordates. The branchiomeric muscles of vertebrates consist of the pharyngeal and laryngeal muscles whereas the orobranchial muscles of chordates consist of the gill and mouth muscles/cavity. These orobranchial muscles begin to develop in the early larval stages of the cephalochordates. The muscles eventually form into the adult hood during metamorphosis. Specific gene expression and neuron pathways suggest the homological connections between vertebrates and the nonvertebral cephalochordates. The Brachyury gene expression of the notochord is just one of the few genetic characteristics that give evidence to homological connections of the vertebral and cephalochordate. Although there are evolutionary connections between the two groups, their functions of the notochord are no longer the same over time. The notochord consists of striated muscles that form a tough, cylinder rod along the back of the cephalochordate. The notochord of the cephalochordate is functioned to allow body movement within their water environment whereas vertebrates use the notochord for body formation.

Intro paragraph

A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). All chordates possess 5 synapomorphies, or primary characteristics, at some point during their larval or adulthood stages that distinguish them from all other taxa. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. Chordates get their name from their characteristic “notochord”, which plays a significant role in chordate structure and movement. Chordates are also bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit metameric segmentation.

Week 11: Second Draft

Abby's Second Draft edits

Cephalochordate lancelet Anatomy

*Underlined text are new edits.

Old: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide. With the presence of a notochord, adult amphioxus are able to swim and tolerate the tides of coastal environments, but they are most likely to be found within the sediment of these communities.

New: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called Amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide. With the presence of a notochord, adult amphioxus are able to swim and tolerate the tides of coastal environments, but they are most likely to be found within the sediment of these communities.

Old: Cephalochordates are segmented marine animals that possess elongated bodies containing a notochord that extends the length of the body from head to tail. They are only a few centimeters in length and due to their lack of a mineralized skeleton, their presence in the fossil record is minimal. There is a famous fossil shale from the Middle Cambrian, the Burgess Shale of British Columbia, which has yielded Pikaia fossils. Recently, a different cephalochordate fossil (Yunnanozoon) has been found in south China. It dates to the early Cambrian period, and is the earliest known fossil of the cephalochordate lineage.

New: Cephalochordates are segmented marine animals that possess elongated bodies containing a notochord that extends the length of the body from head to tail. They are only a few centimeters in length and due to their lack of a mineralized skeleton, their presence in the fossil record is minimal. A few fossils have been found such as the Burgess Shale of British Columbia which contained the fossils of Pikaia, and the Yunnanozoon fossil which also dates back to the Cambrian period.

Noah's Second Draft edits

Cephalochordate feeding structures

- Added a figure from Wikimedia Commons that shows the structures associated with Cephalochordate Feeding. I will be adding this figure to my 'Feeding' section draft

- My proposed changes, edits, and editions to the Cephalochordate article will be underlined to distinguish from the original article and my previous draft.

Cephalochordate article

Morphology Section

• New: The general cephalochordate body plan is considered to be a dorsoventrally flipped version of earlier deuterostomes. Gene-expression studies on embryonic patterning suggest that body axis formation has inverted somewhere between hemichordates and chordates, where the ventral formation of body structures in earlier hemichordates is observed to be dorsal in cephalochordates.

Feeding Section

• Old: Cephalochordates employ a filter feeding system to consume microorganisms. The oral hood serves as the entrance for food particles, and possesses buccal cirri, which assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the mouth and pharynx form a specialized "wheel organ" situated at the dorsal and posterior end of the cavity. The motion of the cilia resembles the motion of a turning wheel, hence the organ's name, and transports the captured food particles. Behind this organ is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Following this, the food is transferred to the gut, and excess water is pumped from the pharynx through the pharyngeal slits. This excess water passes through the atriopore and is then excreted from the body.
• New: Cephalochordates employ a filter feeding system to consume microorganisms. The oral hood serves as the entrance for incoming food particles. Buccal cirri, projections that originate from the free edge of the oral hood, assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the inside walls of the oral hood then bring the food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causes cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transferred to the gut and excess water is pumped out of the pharynx through the pharyngeal slits. Excess water passes through the single atriopore as it is excreted from the body.

Intro Paragraph

• Old: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates are chordates with all 5 synapomorphies, the characteristics all chordates have during the larval or adulthood stages. These synapomorphies include: notochord, dorsal hollow nerve cord, endostyle, pharynx and post-anal tail. The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes.
• New: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called Amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide. With the presence of a notochord, adult amphioxus are able to swim and tolerate the tides of coastal environments, but they are most likely to be found within the sediment of these communities.

Chordate article

Intro paragraph

• Old: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail: these four anatomical features define this phylum. Chordates are also bilaterally symmetric, and have a coelom, metameric segmentation, and circulatory system.
• New: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). All chordates possess 5 synapomorphies, or primary characteristics, at some point during their larval or adulthood stages that distinguish them from all other taxa. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. Chordates get their name from their characteristic “notochord”, which plays a significant role in chordate structure and movement. Chordates are also bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit metameric segmentation.

NoahMcGoff (talk) 04:48, 30 April 2021 (UTC)

Katelyn's Second Draft Edits

Morphological Section

• Old additions about muscles: Studies have shown that there is a correlation between the branchiomeric muscles of vertebrates with the orobranchial muscles within the pharynx of chordates. These orobranchial muscles begin to develop in the early larval stages of the cephalochordates. The muscles eventually form into the adult hood during metaphorphsis. (I will add on more later, I just need to fully understand and research more)
• New additions: Studies have shown that there is a correlation between the branchiomeric muscles of vertebrates with the orobranchial muscles within the pharynx of chordates. The branchiomeric muscles of vertebrates consist of the pharyngeal and laryngeal muscles whereas the orobranchial muscles of chordates consist of the gill and mouth muscles/cavity. These orobranchial muscles begin to develop in the early larval stages of the cephalochordates. The muscles eventually form into the adult hood during metamorphosis. Specific gene expression and neuron pathways suggest the homological connections between vertebrates and the nonvertebral cephalochordates. The Brachyury gene expression of the notochord is just one of the few genetic characteristics that give evidence to homological connections of the vertebral and cephalochordate. Although there are evolutionary connections between the two groups, their functions of the notochord are no longer the same over time. The notochord consists of striated muscles that form a tough, cylinder rod along the back of the cephalochordate. The notochord of the cephalochordate is functioned to allow body movement within their water environment whereas vertebrates use the notochord for body formation.

Feeding Section

• Old changes/additions: Cephalochordates have developed a filter feeding system, called the oral hood, that serves as the entrance for incoming food particles. The free edge of the oral hood contains Buccal cirri, small filament-like projections, that assist in sifting out larger food particles before they enter the buccal cavity. These projections are chemoreceptors that stimulate the epithelial cilia lining inside the walls of the oral hood to bring food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causing cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before transferring to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transported to the gut while excess water is pumped out of the pharynx through the pharyngeal slits. The excess water will exit the atrium using the single atriopore as it is excretes from the body.

• New changes/additions (just added citations and simplifying/fixing words): Cephalochordates have developed a filter feeding system, called the oral hood, that serves as the entrance for incoming food particles. The free edge of the oral hood contains Buccal cirri, small filament-like projections, that assist in sifting out larger food particles before they enter the buccal cavity. These projections are chemoreceptors that stimulate the epithelial cilia lining inside the walls of the oral hood to bring food particles into the mouth. The coordinated movement of several ciliated tracts help facilitate food ingestion through a rotating motion that is similar to that of a wheel, causing cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before transferring to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transported to the gut while excess water is pumped out of the pharynx through the pharyngeal slits. The excess water excretes from the body using a single atriopore of the atrium.

Week 9: Checklist For Second Draft

Chordate article

Intro paragraph

• Old: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail: these four anatomical features define this phylum. Chordates are also bilaterally symmetric, and have a coelom, metameric segmentation, and circulatory system.
• New: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). All chordates possess 5 synapomorphies, or primary characteristics, at some point during their larval or adulthood stages that distinguish them from all other taxa. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. Chordates get their name from their characteristic “notochord”, which plays a significant role in chordate structure and movement. Chordates are also bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit metameric segmentation.

NoahMcGoff (talk) 04:48, 30 April 2021 (UTC)

Week 9: Response to Peer Reviews

Noah

Comments from Dr. Schutz

• In morphology section, I will only cite Kardong at the end of first sentence since the rest of the information in this paragraph is from the same source and is in sequence.
• I will crosslink the Lancelet Wikipedia page when able.
• I will try to find another image to contribute in either the feeding or morphology section. We already have found one image that for some reason was included at the bottom of our ‘References’ section on our group page, however, I do not believe this image was seen because it is located in the wrong place.

Comments from Peers

• Since several classmates commented that it was difficult to compare the changes that I made to the original version, I will either bold or highlight my changes to make the review process easier for the reviewer.
• In my proposed edits to the ‘Chordate’ page, one peer felt that the sentence “Chordates get their name from their characteristic “notochord”, which plays a significant role in chordate structure and movement" was jammed into the paragraph. I understand what they are saying, but I do not think that this sentence ruins the flow of the paragraph.
• Several peers also mentioned that I should include a section that details the 5 synapomorphies more in depth, however, Dr. Schutz stated early on that we should link to different articles so that we limit duplicating information that already exists. This is why instead of going in-depth on the 5 synapomorphies cephalochordates share, I instead include a link to the ‘Chordate’ page that describes each of them further and I mention this in the text.
• I was also recommended to expand the ‘Morphology’ section I created, and that is one of my future plans for the drafts to come.
• Someone also mentioned that I started the feeding section with a quote, however, I put quotations around my whole edits section but then forgot to remove the quotation marks before posting it. In other words, there are no actual quotes in this section.

Abby

- I need to capitalize and italicize "Amphioxus"

- Fix my lancelet article citation

- Add a section to the draft that discusses the image we plan on contributing.

- I might reincorporate the sentence that discusses fossils being found in old rocks predating vertebrates if I can find a citation to back it up.

- I plan on leaving the information about how the notochord is helpful for swimming in the introduction but I could also add more information about the notochord to the morphology section.

- I need to italicize Asymmetron Lucayanum since it is a scientific name.

- I might bold the content that I add to certain sections so it is easier for the reader to track my edits.

Katelyn

Analyzing and reading the peer reviews I received from my first draft, I have a better understanding on what I need to work on for this next assignment. My Checklist is:

Dr. Schutz's Feedback:

• Need to keep tabs on crosslinking with "Lancelets"
• Need to simplify certain terms “branchiomeric muscles of vertebrates with the orobranchial" for those who do not fully understand these terms.

Peer Reviews:

• adding citation and references to my paragraphs. I realized that I need to figure out how to properly reference articles so I do not intentionally plagiarize.
• Need to show my edits in the feeding section. I can see where peer reviewers were having a hard timing trying to find what I changed to the feeding section as well as Noah's edits.
• I need to decide whether to fuse my additions about the muscular system with the morphological section Noah is working on or making it its own section.
• I need to definitely add more detail to the muscular section.
• Make sure all of our edits on the feeding section are considered and added to make sure the feeding section is properly corrected.
• I need to find more citations that will benefit my section about the muscles.

Week 6: Drafting Edits

Abby's Edits to Cephalochordate

Old (Noah's Edit): A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide.

New addition to Noah's edit: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide. With the presence of a notochord, adult amphioxus are able to swim and tolerate the tides of coastal environments, but they are most likely to be found within the sediment of these communities.

Old (2): Characteristics of Cephalochordata include that they are segmented marine animals that possess elongated bodies with a notochord that extends the length of the body, extending from head to tail, persisting throughout the animal's life. The members of this subphylum are very small and have no hard parts, making their fossils difficult to find. Fossilized species have been found in very old rocks predating vertebrates. There is a famous fossil shale from the Middle Cambrian, the Burgess Shale of British Columbia, which has yielded Pikaia fossils. Recently, a different cephalochordate fossil (Yunnanozoon) has been found in south China. It dates to the early Cambrian period, and is the earliest known fossil of the cephalochordate lineage. Members of this lineage have numerous gill slits, and have separate sexes.

New (2): Cephalochordates are segmented marine animals that possess elongated bodies containing a notochord that extends the length of the body from head to tail. They are only a few centimeters in length and due to their lack of a mineralized skeleton, their presence in the fossil record is minimal." There is a famous fossil shale from the Middle Cambrian, the Burgess Shale of British Columbia, which has yielded Pikaia fossils. Recently, a different cephalochordate fossil (Yunnanozoon) has been found in south China. It dates to the early Cambrian period, and is the earliest known fossil of the cephalochordate lineage.

Noah's edits to Cephalochordate

Morphology Section

• New/beginning: The general cephalochordate body plan is considered to be a dorsoventrally flipped version of earlier deuterostomes. Gene-expression studies on embryonic patterning suggest that body axis formation has inverted somewhere between hemichordates and chordates, where the ventral formation of body structures in earlier hemichordates is observed to be dorsal in cephalochordates.

Feeding Section

• Old: Cephalochordates employ a filter feeding system to consume microorganisms. The oral hood serves as the entrance for food particles, and possesses buccal cirri, which assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the mouth and pharynx form a specialized "wheel organ" situated at the dorsal and posterior end of the cavity. The motion of the cilia resembles the motion of a turning wheel, hence the organ's name, and transports the captured food particles. Behind this organ is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Following this, the food is transferred to the gut, and excess water is pumped from the pharynx through the pharyngeal slits. This excess water passes through the atriopore and is then excreted from the body.
• New: "The oral hood serves as the entrance for incoming food particles. Buccal cirri, projections that originate from the free edge of the oral hood, assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the inside walls of the oral hood then bring the food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causes cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transferred to the gut and excess water is pumped out of the pharynx through the pharyngeal slits. Excess water passes through the single atriopore as it is excreted from the body."

Intro Paragraph

• Old: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates are chordates with all 5 synapomorphies, the characteristics all chordates have during the larval or adulthood stages. These synapomorphies include: notochord, dorsal hollow nerve cord, endostyle, pharynx and post-anal tail. The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes.
• New: A cephalochordate (from Greek: κεφαλή kephalé, "head" and χορδή khordé, "chord") is an animal in the chordate subphylum, Cephalochordata. They are commonly called amphioxus or lancelets. Cephalochordates possess 5 synapomorphies, or primary characteristics, that all chordates have at some point during their larval or adulthood stages. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle, pharyngeal slits, and a post-anal tail (see chordate for descriptions of each). The fine structure of the cephalochordate notochord is best known for the Bahamas lancelet, Asymmetron lucayanum. Cephalochordates are represented in modern oceans by the Amphioxiformes and are commonly found in warm temperate and tropical seas worldwide.NoahMcGoff (talk) 02:10, 24 March 2021 (UTC)

Noah's edits to Chordate

Intro paragraph

• Old: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail: these four anatomical features define this phylum. Chordates are also bilaterally symmetric, and have a coelom, metameric segmentation, and circulatory system.
• New: A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). All chordates possess 5 synapomorphies, or primary characteristics, at some point during their larval or adulthood stages that distinguish them from all other taxa. These 5 synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. Chordates get their name from their characteristic “notochord”, which plays a significant role in chordate structure and movement. Chordates are also bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit metameric segmentation.NoahMcGoff (talk) 02:10, 24 March 2021 (UTC)

Katelyn's edits to Cephalochordate

• Morphological Section
  • Noah's New/beginning Morphological Section: The general cephalochordate body plan is considered to be a dorsoventrally flipped version of earlier deuterostomes. Gene-expression studies on embryonic patterning suggest that body axis formation has inverted somewhere between hemichordates and chordates, where the ventral formation of body structures in earlier hemichordates is observed to be dorsal in cephalochordates.
  • My additions including muscles: Studies have shown that there is a correlation between the branchiomeric muscles of vertebrates with the orobranchial muscles within the pharynx of chordates. These orobranchial muscles begin to develop in the early larval stages of the cephalochordates. The muscles eventually form into the adult hood during metaphorphsis. (I will add on more later, I just need to fully understand and research more.)
• Feeding Section
  • Noah's new edits: "The oral hood serves as the entrance for incoming food particles. Buccal cirri, projections that originate from the free edge of the oral hood, assist in sifting out larger food particles before they enter the buccal cavity. Epithelial cilia lining the inside walls of the oral hood then bring the food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causes cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before being brought to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transferred to the gut and excess water is pumped out of the pharynx through the pharyngeal slits. Excess water passes through the single atriopore as it is excreted from the body."
  • My changes/additions: Cephalochordates have developed a filter feeding system, called the oral hood, that serves as the entrance for incoming food particles. The free edge of the oral hood contains Buccal cirri, small filament-like projections, that assist in sifting out larger food particles before they enter the buccal cavity. These projections are chemoreceptors that stimulate the epithelial cilia lining inside the walls of the oral hood to bring food particles into the mouth. The coordinated movement of several ciliated tracts helps facilitate food ingestion through a rotating motion that is similar to that of a wheel, causing cilia to be referred to as “wheel organ”. One of these ciliated tracts located on the oral hood forms a ciliated cavity, called Hatschek's pit, which aids in food collection by secreting mucous into the buccal cavity to capture food particles. Located behind the buccal cirri is the velum, which acts as an internal filter before food enters the pharynx. The food particles adhere to secreted mucus on the pharyngeal bars before transferring to the epibranchial groove on the dorsal side of the pharynx. Food particles are then transported to the gut while excess water is pumped out of the pharynx through the pharyngeal slits. The excess water will exit the atrium using the single atriopore as it is excretes from the body."

Week 5: Find Your Sources

Articles

• Course textbook (not an article): Kardong, Kenneth. Vertebrates: Comparative Anatomy, Function, and Evolution.
  • (Noah) can be used to create the 'Morphology' section and to revise/expand the 'Feeding' section.
• Genetics/Ancestral origin section
  • (Noah) Genetic ancestry to vertebrates: "The amphioxus genome illuminates vertebrate origins and cephalochordate biology" https://genome.cshlp.org/content/18/7/1100.short
  • (Noah)The role of RA in cephalochordate amphioxus CNS development: https://www.sciencedirect.com/science/article/pii/S0012160606007494
• Morphology section
  • (Noah) The sensory PNS in the tail of cephalochordates (provides detail about the tail): https://onlinelibrary.wiley.com/doi/full/10.1002/cne.24913?casa_token=x33iAiQXuBIAAAAA%3AvHDlclTNwg0YXMJYKSY72QqDeXmUo3BJ8L4aRU16N5Pp8BQO2NMCUq882kNlTGYC97C4iiF9f2PZdtSY
  • (Noah) Tail regeneration (regeneration of body parts) In cephalochordates: https://onlinelibrary.wiley.com/doi/full/10.1002/jmor.21297?casa_token=5ARs9cNybsAAAAAA%3AwTi3gHzkuUtERdozwJKzGhsfKc27_X5NiVHaw333NmmN8j1t9XSQGoKbvlpVAJSXN5MWweTXIpF--MWF
  • (Abby) Describes the morphological features of cephalochordates."A phylogeny of the hemichordates based on morphological features"
  • (Abby) Use this source to rewrite a sentence that is plagiarized within the article about why cephalochordates are hard to find fossils of.
  • (Katelyn) A Review Development, Metamorphosis, Morphology, and Diversity: The Evolution of Chordate Muscles and the Origin of Vertebrates
    • Sections discuss about early evolution and jaw structure of cephalochordates
    • https://anatomypubs.onlinelibrary.wiley.com/doi/epdf/10.1002/dvdy.24245.

Images or other media

• (Noah/Abby) Replace the oral hood figure in the 'Feeding section' with a more detailed figure such as the one of a lancelet below. We can then describe, in greater depth than what is already presented, why the oral hood and other structures aid in cephalochordate feeding.

Feedback: Discussion and Adding to an Article

I can see that proposed edits got submitted to the cephalochordate page...which is grand. However, no one has responded. They may still but this indicates that the page is not being monitored much and that work on it would be very good to initiate. I am so glad to see you actually citing in your pages and making live links. A few of you are doing this in your sections, but a few are not and the practice is critical. In particular, those in-text citations are super important to practice. The Kardong Text citation should not be in all caps

I’d like to see a breakdown of who is doing what written down in the group page either as labels or dividers. I think working on all of it together is fine, but breaking down tasks and responsibilities is also critical to group work and I want to see that in the Group sandbox. 

The above will be really critical this week as you begin to draft actual sections complete with citations and links. So take your topics and start fleshing them out and deciding who is going to work on what sections. Also, begin to consider links to other relevant wiki pages and start incorporating them into your draft text for next week. You have a really good framework for potential edits and contributions, so I think you have set yourselves up really well for a solid first draftOsquaesitor (talk) 20:23, 23 March 2021 (UTC)