Vetulicolia

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Vetulicolia
Temporal range: about 535–501  Ma
Vetucolia.JPG
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Superphylum: Deuterostomia
Phylum:† Vetulicolia
Shu et al. 2001
Type species
† Vetulicola cuneata
Hou, 1987
Classes

Vetulicolia [note 1] is a phylum of bilaterian animals encompassing several extinct species belonging to the Cambrian period. [1] [2] The phylum was created by Degan Shu and his research team in 2001, [3] and named after Vetulicola cuneata , the first species of the phylum described in 1987. [4]

Contents

The vetulicolian body plan comprises two parts: a voluminous rostral (anterior) forebody, tipped with an anteriorly positioned mouth and lined with a lateral row of five round to oval-shaped openings on each side, which have been interpreted as gills (or at least orifices in the vicinity of the pharynx); and a caudal (posterior) section that primitively comprises seven body segments and functions as a tail. All vetulicolians lack preserved appendages of any kind, having no legs, feelers or even eye spots. [5] The area where the anterior and posterior parts join is constricted. [6]

Their taxonomic affinity has been uncertain; they have been considered to represent stem- and crown-group arthropods, stem-group vertebrates, [7] and early deuterostomes (a group which as a whole includes the vertebrates, other invertebrate chordates, echinoderms and hemichordates). The general scientific consensus before 2001 considered them early limbless arthropods but now considers them early deuterostomes. [8] Vetulicolian fossils examined in 2014 show the presence of notochord-like structures, and it was concluded that vetulicolians are crown-group chordates and probably related to modern tunicates. [9] Research from 2017 rather indicates vetulicolians are related to Saccorhytus , another basal deuterostome group, [10] although another study shows possibility that Saccorhytus is ecdysozoan instead of deuterostome. [11]

Taxonomy and evolution

Vetulicola cuneata fossil. Vetulicola cuneata uetsurikora kunieta 1.jpg
Vetulicola cuneata fossil.

Vetulicolia as a phylum was created by Chinese palaeontologist Degan Shu and his research team at the Northwest University in Xi'an, China, along with Simon Conway Morris at the University of Cambridge in 2001. [3] The name was derived from Vetulicola cuneata, the first species described by Hou Xian-guang in 1987 from the Lower Cambrian Chiungchussu Formation in Chengjiang, China. [2] [4] The purpose was to include all related Cambrian animals known under the families Didazoonidae ( Didazoon , Pomatrum , and Xidazoon ) and Vetulicolidae ( Vetulicola , and Banffia ) as a separate group of animals. [1] [3] Other animals which may be related include the yunnanozoans. [3]

The taxonomic placement of the vetulicolians remains controversial. The original researcher Shu is of the opinion that the vetulicolians probably represent an early type of deuterostomes, and that this implies that segmentation in cephalochordates and vertebrates may be derived from the common ancestor of protostomes and deuterostomes. [7] However, Derek Briggs of Yale University and his team who described Skeemella from the Middle Cambrian of Utah regard it as having affinity to protostomes with important arthropod features, thus confounding assignment of Vetulicolia to Deuterostomia. [12] Thurston C. Lacalli of the University of Saskatchewan, Saskatoon, Canada, agreed that the group are deuterostomes, but suggested that the animals were more likely related to tunicates. [13]

Dominguez and Jefferies have argued, based on morphological analysis, that Vetulicola (and by implication, other vetulicolians) is a urochordate, and probably a stem-group larvacean. Some question the relation to tunicates and larvaceans, as there is no evidence of segmentation in tunicates, larval or adult, that is comparable to segmentation in vetulicolians, that the anus of urochordates is within the atrium, while that of vetulicolians is positioned at the terminal end of the tail, and, perhaps most importantly, there is no exhalant siphon, or analogous structure, seen in vetulicolians. [14] However, a discovery of a new vetulicolian, Nesonektris aldridgei, from Australia in 2014 supported a position close to urochordates for vetulicolians. [9]

The monophyly of Deuterostomia is not strongly evidenced. [15] [16] If deuterostomes are paraphyletic, pharyngeal slits were probably present in the common ancestor of Bilateria and vetulicolians may be stem-group protostomes that retained the ancestral pharyngeal slits. [16] If this is the case, banffids, which appear to lack pharyngeal slits, may be more closely related to crown-group protostomes than other vetulicolians. [16]

Ecology and lifestyle

Fossil of a Vetulicola rectangulata. Vetulicola rectangulata 01.jpg
Fossil of a Vetulicola rectangulata.

From their superficially tadpole-like forms, leaf or paddle-shaped tails, and various degrees of streamlining, it is assumed that all vetulicolians discovered to date were swimming animals that spent much, if not all, of their time living in water. [14] Some groups, like the genus Vetulicola, were more streamlined (complete with ventral keels) than other groups, such as the tadpole-like Didazoonidae. [14]

Because all vetulicolians had mouths which had no features for chewing or grasping, it is assumed that they were not predators. [14] Since vetulicolians possessed gill slits, many researchers regard these organisms as planktivores. The sediment infills in the guts of their fossils have caused some to suggest that they were deposit feeders. This idea has been contested, as deposit feeders tend to have straight guts, whereas the hindguts of vetulicolians were spiral-shaped. Some researchers propose that the vetulicolians were "selective deposit-feeders" which actively swam from one region of the seafloor to another, while supplementing their nutrition with filter-feeding. [14]

Classification

Notes

  1. ↑ The taxon name, Vetulocolia, is derived from the type genus, Vetulicola , which is a compound Latin word composed of vetuli "old" and cola "inhabitant".

Related Research Articles

<span class="mw-page-title-main">Chordate</span> Phylum of animals having a dorsal nerve cord

A chordate is a deuterostomic animal belonging to the phylum Chordata. All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics (synapomorphies) that distinguish them from other taxa. These five synapomorphies are a notochord, a hollow dorsal nerve cord, an endostyle or thyroid, pharyngeal slits, and a post-anal tail. The name "chordate" comes from the first of these synapomorphies, the notochord, which plays a significant role in chordate body plan structuring and movements. Chordates are also bilaterally symmetric, have a coelom, possess a closed circulatory system, and exhibit metameric segmentation.

<span class="mw-page-title-main">Maotianshan Shales</span> Series of Early Cambrian deposits in the Chiungchussu Formation

The Maotianshan Shales (帽天山页岩) are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation, famous for their Konservat Lagerstätten, deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales form one of some forty Cambrian fossil locations worldwide exhibiting exquisite preservation of rarely preserved, non-mineralized soft tissue, comparable to the fossils of the Burgess Shale of British Columbia, Canada. They take their name from Maotianshan Hill in Chengjiang County, Yunnan Province, China.

<i>Yunnanozoon</i> Cambrian fossil chordate

Yunnanozoon lividum is an extinct species of bilaterian animal from the Lower Cambrian Chengjiang biota of Yunnan province, China. Its affinities have been long the subject of controversy.

<i>Vetulicola</i> Fossil genus of marine animal

Vetulicola is an extinct genus of marine animal discovered from the Cambrian of China. It is the eponymous member of the enigmatic phylum Vetulicolia, which is of uncertain affinities but may belong to the deuterostomes. The name was derived from Vetulicola cuneata, the first species described by Hou Xian-guang in 1987 from the Lower Cambrian Chiungchussu Formation in Chengjiang, China.

<i>Pomatrum</i> Cambrian age animal

Pomatrum is an extinct vetulicolian, the senior synonym of Xidazoon; the latter taxon was described by Shu, et al. (1999) based on fossils found in the Qiongzhusi (Chiungchussu) Formation, Yu'anshan Member, Lower Cambrian, Haikou, (Kunming), about 50 km west of Chengjiang, China. It has been likened to the chordate Pipiscius.

<i>Banffia</i> Extinct genus of Cambrian organisms

Banffia is a genus of animals described from Middle Cambrian fossils. The genus commemorates Banff, Alberta, near where the first fossil specimens were discovered. Its placement in higher taxa is controversial. It is considered to be a member of the enigmatic phylum Vetulicolia.

<span class="mw-page-title-main">Vetulicolidae</span> Extinct family of soft-bodied animals

Vetulicolidae is an extinct family of Early Cambrian deuterostomes comprising two genera: Vetulicola and Ooedigera.

<span class="mw-page-title-main">Deuterostome</span> Superphylum of bilateral animals

Deuterostomes are bilaterian animals of the superphylum Deuterostomia, typically characterized by their anus forming before the mouth during embryonic development. Deuterostomia is further divided into 4 phyla: Chordata, Echinodermata, Hemichordata, and the extinct Vetulicolia known from Cambrian fossils. The extinct clade Cambroernida is also thought to be a member of Deuterostomia.

<i>Vetulicola cuneata</i> Extinct species of animal

Vetulicola cuneata is a species of extinct animal from the Early Cambrian Chengjiang biota of China. It was described by Hou Xian-guang in 1987 from the Lower Cambrian Chiungchussu Formation, and became the first animal under an eponymous phylum Vetulicolia.

<i>Herpetogaster</i> Extinct genus of Cambrian animals

Herpetogaster is an extinct cambroernid genus of animal from the Early Cambrian Chengjiang biota of China, Blang Formation of China, Pioche Formation of Nevada and Middle Cambrian Burgess Shale of Canada containing the species Herpetogaster collinsi and Herpetogaster haiyanensis.

<i>Ooedigera</i> Ovoid Cambrian animal with a bulbous tail

Ooedigera peeli is an extinct vetulicolian from the Early Cambrian of North Greenland. The front body was flattened horizontally, oval-shaped, likely bearing a reticulated or anastomosing pattern, and had 5 evenly-spaced gill pouches along the midline. The tail was also bulbous and flattened horizontally, but was divided into 7 plates connected by flexible membranes, allowing movement. Ooedigera likely swam by moving side-to-side like a fish. It may have lived in an oxygen minimum zone alongside several predators in an ecosystem based on chemosynthetic microbial mats, and was possibly a deposit or filter feeder living near the seafloor.

<i>Skeemella</i>

Skeemella clavula is an elongate animal from what is now the Middle Cambrian Wheeler Shale and Marjum lagerstätte of Utah. It has been classified with the vetulicolians.

<i>Vetulicola rectangulata</i> Extinct animal from Cambrian of the Chengjiang biota of China

Vetulicola rectangulata is a species of extinct animal from the Early Cambrian of the Chengjiang biota of China. Regarded as a deuterostome, it has characteristic rectangular anterior body on which the posterior tail region is attached. It was described by Luo Huilin and Hu Shi-xue in 1999.

<i>Nesonektris</i> Extinct genus of Cambrian Era Chordate

Nesonektris aldridgei is an extinct deuterostome chordate from the Late Botomian-aged Emu Bay Shale Lagerstätte in Kangaroo Island, Australia. So far, it is the fourth described vetulicolian that is not restricted to the Maotianshan Shales.

<span class="mw-page-title-main">Olfactores</span> Clade of animals comprising vertebrates and tunicates

Olfactores is a clade within the Chordata that comprises the Tunicata (Urochordata) and the Vertebrata. Olfactores represent the overwhelming majority of the phylum Chordata, as the Cephalochordata are the only chordates not included in the clade. This clade is defined by a more advanced olfactory system which, in the immediate vertebrate generation, caused the appearance of nostrils.

<i>Saccorhytus</i> Extinct monospecific genus of Ediacaran Ecdysozoan

Saccorhytus is an extinct genus of animal possibly belonging to the superphylum Ecdysozoa, and it is represented by a single species, Saccorhytus coronarius. The organism lived approximately 540 million years ago in the beginning of the Cambrian period. Initially proposed as a deuterostome, which would make it the oldest known species of this superphylum, it has since been determined to belong to a protostome group called the ecdysozoans.

Shankouclava is an extinct genus of tunicates. It represents the oldest candidate member of this group, dating to 518 million years ago. It has been found in the Lower Cambrian Maotianshan Shale at Shankou village, Anning, near Kunming. Each of the eight specimens found and used for description were isolated, suggesting that the genus was solitary and not colonial.

<i>Beidazoon</i> Extinct species of Cambrian organism

Beidazoon venustum is a deuterostome from the deuterostome group Vetulicolia. It originates from the lower Cambrian Chengjiang biota of Yunnan Province, China. Beidazoon was a marine organism discovered by Degan Shu in 2005.

<span class="mw-page-title-main">Vetulocystidae</span> Extinct family of animals

Vetulocystidae is the only family of the taxon Vetulocystida, which is a group of extinct deuterostomes of uncertain phylogenetic position. Vetulocystidae is made up of the genera Vetulocystis, Dianchicystis and Thylacocercus.

The Cambrian chordates are an extinct group of animals belonging to the phylum Chordata that lived during the Cambrian, between 538 and 485 million years ago. The first Cambrian chordate known is Pikaia gracilens, a lancelet-like animal from the Burgess Shale in British Columbia, Canada. The discoverer, Charles Doolittle Walcott, described it as a kind of worm (annelid) in 1911, but it was later identified as a chordate. Subsequent discoveries of other Cambrian fossils from the Burgess Shale in 1991, and from the Chengjiang biota of China in 1991, which were later found to be of chordates, several Cambrian chordates are known, with some fossils considered as putative chordates.

References

  1. 1 2 Shu, Degan (2005). "On the Phylum Vetulicolia". Chinese Science Bulletin. 50 (20): 2342–2354. Bibcode:2005ChSBu..50.2342S. doi:10.1007/BF03183746. ISSN   1001-6538. S2CID   86827605.
  2. 1 2 McMenamin, Mark A. S. (2019). "Cambrian Chordates and Vetulicolians". Geosciences. 9 (8): 354. Bibcode:2019Geosc...9..354M. doi: 10.3390/geosciences9080354 . ISSN   2076-3263.
  3. 1 2 3 4 Shu, D. G.; Conway Morris, S.; Han, J.; Chen, L.; Zhang, X. L.; Zhang, Z. F.; Liu, H. Q.; Li, Y.; Liu, J. N. (2001-11-22). "Primitive deuterostomes from the Chengjiang Lagerstätte (Lower Cambrian, China)". Nature. 414 (6862): 419–424. Bibcode:2001Natur.414..419S. doi:10.1038/35106514. ISSN   0028-0836. PMID   11719797. S2CID   4345484.
  4. 1 2 Briggs, Derek E. G.; Fortey, Richard A. (2005). "Wonderful strife: systematics, stem groups, and the phylogenetic signal of the Cambrian radiation". Paleobiology. 31 (2_Suppl): 94–112. doi:10.1666/0094-8373(2005)031[0094:WSSSGA]2.0.CO;2. ISSN   0094-8373. S2CID   44066226.
  5. ↑ Ailin, C.; Hongzhen, F.; Maoyan, Z.H.U.; Dongsheng, M.A.; Ming, L.I. (2003), "A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China", Acta Geologica Sinica, 77 (3): 281–287, doi:10.1111/j.1755-6724.2003.tb00742.x, S2CID   128895860 [ dead link ]
  6. 1 2 McMenamin, Mark A. S. (11 August 2019). "Cambrian Chordates and Vetulicolians". Geosciences. 9 (8): 354. Bibcode:2019Geosc...9..354M. doi: 10.3390/geosciences9080354 .
  7. 1 2 Shu, Degan (2003). "A paleontological perspective of vertebrate origin". Chinese Science Bulletin. 48 (8): 725–735. Bibcode:2003ChSBu..48..725S. doi:10.1007/BF03187041. S2CID   85163902.
  8. ↑ Dominguez, Patricio and Jeffries, Richard. (2003). Fossil evidence on the origin of appendicularians. Paper read at International Urochordate Meeting 2003. Abstract at [2] – URL retrieved June 22, 2006.
  9. 1 2 3 García-Bellido, Diego C; Paterson, John R (2014). "A new vetulicolian from Australia and its bearing on the chordate affinities of an enigmatic Cambrian group". BMC Evolutionary Biology. 14: 214. doi: 10.1186/s12862-014-0214-z . PMC   4203957 . PMID   25273382.
  10. ↑ Han, Jian; Conway Morris, Simon; Ou, Qiang; Shu, Degan; Huang, Hai (2017). "Meiofaunal deuterostomes from the basal Cambrian of Shaanxi (China)". Nature. 542 (7640): 228–231. Bibcode:2017Natur.542..228H. doi:10.1038/nature21072. PMID   28135722. S2CID   353780.
  11. ↑ Liu, Yunhuan; Carlisle, Emily; Zhang, Huaqiao; Yang, Ben; Steiner, Michael; Shao, Tiequan; Duan, Baichuan; Marone, Federica; Xiao, Shuhai; Donoghue, Philip C. J. (2022-08-17). "Saccorhytus is an early ecdysozoan and not the earliest deuterostome". Nature. 609 (7927): 541–546. Bibcode:2022Natur.609..541L. doi:10.1038/s41586-022-05107-z. hdl: 1983/454e7bec-4cd4-4121-933e-abeab69e96c1 . ISSN   1476-4687. PMID   35978194. S2CID   251646316.
  12. ↑ Briggs; et al. (2005). "A new metazoan from the Middle Cambrian of Utah and the nature of the Vetulicolia". Palaeontology. 48 (4): 681–686. doi: 10.1111/j.1475-4983.2005.00489.x .
  13. ↑ Lacalli, Thurston C. (2002). "Vetulicolians—are they deuterostomes? chordates?". BioEssays. 24 (3): 208–211. doi:10.1002/bies.10064. PMID   11891757.
  14. 1 2 3 4 5 6 Aldridge, Richard J.; Hou, Xian-guang; Siveter, David J.; Siveter, Derek J.; Sarah E., Gabbott (2007). "The systematics and phylogenetic relationships of vetulicolians". Palaeontology. 50: 131–168. doi:10.1111/j.1475-4983.2006.00606.x. S2CID   85722738.
  15. ↑ Philippe, Hervé; Poustka, Albert J.; Chiodin, Marta; Hoff, Katharina J.; Dessimoz, Christophe; Tomiczek, Bartlomiej; Schiffer, Philipp H.; Müller, Steven; Domman, Daryl; Horn, Matthias; Kuhl, Heiner; Timmermann, Bernd; Satoh, Noriyuki; Hikosaka-Katayama, Tomoe; Nakano, Hiroaki; Rowe, Matthew L.; Elphick, Maurice R.; Thomas-Chollier, Morgane; Hankeln, Thomas; Mertes, Florian; Wallberg, Andreas; Rast, Jonathan P.; Copley, Richard R.; Martinez, Pedro; Telford, Maximilian J. (2019). "Mitigating Anticipated Effects of Systematic Errors Supports Sister-Group Relationship between Xenacoelomorpha and Ambulacraria". Current Biology. 29 (11): 1818–1826.e6. doi: 10.1016/j.cub.2019.04.009 . hdl: 21.11116/0000-0004-DC4B-1 . ISSN   0960-9822. PMID   31104936.
  16. 1 2 3 Kapli, Paschalia; Natsidis, Paschalis; Leite, Daniel J.; Fursman, Maximilian; Jeffrie, Nadia; Rahman, Imran A.; Philippe, Hervé; Copley, Richard R.; Telford, Maximilian J. (2020-07-02). "Lack of support for Deuterostomia prompts reinterpretation of the first Bilateria". bioRxiv   10.1101/2020.07.01.182915 .
  17. ↑ Vinther, J.; Smith, M. P.; Harper, D. A. T. (2011). "Vetulicolians from the Lower Cambrian Sirius Passet Lagerstätte, North Greenland, and the polarity of morphological characters in basal deuterostomes". Palaeontology. 54 (3): 711–719. doi:10.1111/j.1475-4983.2011.01034.x. S2CID   85602402.
  18. ↑ Chen, Feng, Ma, Li (2003). "A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China". Acta Geologica Sinica. 77 (3): 281–287. doi:10.1111/j.1755-6724.2003.tb00742.x. S2CID   128895860.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ↑ Caron, Jean-Bernard (June 2005). "Banffia constricta, a putative vetulicolid from the Middle Cambrian Burgess Shale". Transactions of the Royal Society of Edinburgh: Earth Sciences. 96 (2): 95–111. doi:10.1017/S0263593300001255. ISSN   0263-5933. S2CID   128851764.
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