Collinsovermis

Collinsovermis is a genus of extinct panarthropod belonging to the group Lobopodia and known from the middle Cambrian Burgess Shale in British Columbia, Canada. It is monotypic having only one species, Collinsovermis monstruosus. After its initial discovery in 1983, Desmond H. Collins popularised it as a unique animal and was subsequently dubbed "Collins' monster" for its unusual super armoured body.[1] The formal scientific description and name were given in 2020.[2]

Collinsovermis
Temporal range:
Life restoration
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
(unranked): Panarthropoda
Phylum: "Lobopodia"
Family: Luolishaniidae
Genus: Collinsovermis
Caron & Aria, 2020
Species:
C. monstruosus
Binomial name
Collinsovermis monstruosus
Caron & Aria, 2020

Discovery

Collinsovermis was discovered in 1983 by Desmond H. Collins, curator of invertebrate palaeontology at the Royal Ontario Museum, from an expedition at Mount Stephen at the Yoho National Park, British Columbia, Canada.[3] It was found among the Burgess Shale that belonged to the middle Cambrian period called Wuliuan, which is around 509 to 505 million years ago. In 1985, Collins presented the discovery before the Geological Society of America, and published the next year in a popular magazine Rotunda in an article "Paradise revisited." Avoiding the scientific nomenclature and systematic description, he referred to it as a "spiny animal with hairy legs."[4]

Naming

In 1991, Italian palaeontologists, Laura Delle Cave and Alberto Mario Simonetta published a preliminary description based on Collins's photographs, and gave the nickname "Collins' monster."[5] The complete systematic description and scientific name were given by Jean-Bernard Caron (Royal Ontario Museum and University of Toronto) and Cédric Aria (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences) in 2020 in the journal Palaeontology. The scientific name Collinsovermis monstruosus literally means Collins' wormy monster.[2] As a unique member of Lobopodia, scientists also created a new family for it as Collinsovermidae.[6]

Description

Diagram

Collinsovermis is a tiny worm-like soft bodied animal measuring about 3 cm long with multiple pairs of stump legs called lobopods. It bears 14 pairs of lobopods, which are closely attached to the main body unlike in other lobopodians. The anterior six pairs are unusual in that they are much longer than the posterior pairs or typical lobopod,[3] and they are attached with fine curved spinules in about 20 pairs arranged in a V (chevron)-shaped stripe. These limbs are also covered in fine setae, and end with a terminal claw. The eight posterior lobopods are stout and smooth, and each with a terminal curved claw. There are pairs of spines matching to each pair of lobopods (on each body segment or somite) on its back, which were likely served a defensive function. The spines are larger at the middle region of the body and taper towards both ends.[2]

The general body appearance resembles that of Luolishania longicruris (discovered in 1989 in China[7]), which is but smaller and with more posterior lobopods.[8] The head is rounded, small, covered with sclerite (exoskeleton) and has a mouth at its front.[2] Such external body sclerites are also present L. longicruris[8] but absent in other closely related luolishaniid lobopods such as Collinsium (discovered in 2015 from China,[9] popularly known as "Hairy Collins's monster"[10][11]) and Acinocricus (discovered in 1988 from Utah, US[12]). The head also bears a pair of antennae-like projections.[2] Collinsovermis is regarded as characteristically most closely related to Acinocricus, with the major differences being large size (up to 10 cm long), five pairs of anterior legs, absence of sclerites and presence of numerous rows of back spines in the latter.[13][14][2]

Ecology

Like other "luolishaniid" lobopodians, Collinsovermis is thought to have been a sessile suspension feeder, using the posterior pairs of limbs to anchor itself to a substrate, while using its spinose anterior appendages to catch small food particles.[2]

References

  1. Powell, Russell (2020). Contingency and Convergence: Toward a Cosmic Biology of Body and Mind. MIT Press. p. 41. ISBN 978-0-262-04339-7.
  2. Caron, Jean‐Bernard; Aria, Cédric (2020). "The Collins' monster, a spinous suspension‐feeding lobopodian from the Cambrian Burgess Shale of British Columbia". Palaeontology. 63 (6): 979–994. doi:10.1111/pala.12499. S2CID 225593728.
  3. García-bellido, Diego C.; Edgecombe, Gregory D.; Paterson, John R.; Ma, Xiaoya (2013). "A 'Collins' monster'-type lobopodian from the Emu Bay Shale Konservat-Lagerstätte (Cambrian), South Australia". Alcheringa: An Australasian Journal of Palaeontology. 37 (4): 474–478. doi:10.1080/03115518.2013.792456. S2CID 129298546.
  4. Collins, Desmond (1986). "Paradise revisited". Rotunda. 19: 37–39. Presented as: A new Burgess shale type fauna in the Middle Cambrian Stephen Formation on Mt Stephen, British Columbia. Geological Society of America. Abstract Number 550 (1985).
  5. Delle Cave, Laura; Simonetta, Alberto M. (2009) [1991]. "Early Palaeozoic arthropods and problems of arthropod phylogeny: with some notes on taxa of doubtful affinities.". In Simonetta, Alberto M.; Conway Morris, Simon (eds.). The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge: Cambridge University Press. pp. 189–244. ISBN 978-0-521-11158-4.
  6. Caron, Jean‐Bernard; Aria, Cédric (2020). "Corrigendum: The Collins' monster, a spinous suspension‐feeding lobopodian from the Cambrian Burgess Shale of British Columbia". Palaeontology. 63 (6): 995–996. doi:10.1111/pala.12509. S2CID 243330614.
  7. Hou, Xian-Guang; Chen, Jun-Yuan (1989). "Luolishania gen. nov. : Un animal marin intermédiaire entre arthropode et annélidé du Cambrien inférieur de Chengjiang dans le Yunnan" [Luolishania gen. nov.: A marine animal intermediate between arthropod and annelid from the Lower Cambrian of Chengjiang in Yunnan]. Gǔshēngwùxué Bào (Acta Palaeontologica Sinica) (in French). 28 (2): 207–213.
  8. Ma, Xiaoya; Hou, Xianguang; Bergström, Jan (2009). "Morphology of Luolishania longicruris (Lower Cambrian, Chengjiang Lagerstätte, SW China) and the phylogenetic relationships within lobopodians". Arthropod Structure & Development. 38 (4): 271–291. doi:10.1016/j.asd.2009.03.001. PMID 19293001.
  9. Yang, Jie; Ortega-Hernández, Javier; Gerber, Sylvain; Butterfield, Nicholas J.; Hou, Jin-bo; Lan, Tian; Zhang, Xi-guang (2015). "A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora". Proceedings of the National Academy of Sciences. 112 (28): 8678–8683. Bibcode:2015PNAS..112.8678Y. doi:10.1073/pnas.1505596112. PMC 4507230. PMID 26124122.
  10. Oldfield, Philip (2015-06-29). "Hairy monster: ancient 'super-armoured' worm discovered in China". The Guardian. Archived from the original on 2015-08-03. Retrieved 2022-01-02.
  11. "Meet the Hairy Collins' Monster, the newly discovered ancient 'superarmored' worm". Washington Post. ISSN 0190-8286. Retrieved 2022-01-02.
  12. Conway Morris, S.; Robison, Richard A. (1988). "More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia". University of Kansas Paleontological Contributions. 122: 1–48. ISSN 0075-5052.
  13. Kimmig, Julien; Strotz, Luke C.; Kimmig, Sara R.; Egenhoff, Sven O.; Lieberman, Bruce S. (2019). "The Spence Shale Lagerstätte: an important window into Cambrian biodiversity". Journal of the Geological Society. 176 (4): 609–619. Bibcode:2019JGSoc.176..609K. doi:10.1144/jgs2018-195. S2CID 134674792.
  14. Caron, Jean-Bernard; Aria, Cédric (2017). "Cambrian suspension-feeding lobopodians and the early radiation of panarthropods". BMC Evolutionary Biology. 17 (1): 29. doi:10.1186/s12862-016-0858-y. PMC 5282736. PMID 28137244.
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