Yohoia

Yohoia
Temporal range:
Life restoration of Y. tenuis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: †Megacheira
Clade: †Cheiromorpha
Order: †Yohoiida
Simonetta & Delle Cave, 1975
Family: †Yohoiidae
Henriksen, 1928
Genus: †Yohoia
Walcott, 1912
Species
  • Y. tenuis Walcott, 1912
  • Y. utahana Conway Morris et al., 2015[1]

Yohoia is an extinct genus of fossil megacheiran arthropod from the Cambrian period. The type species, Yohoia tenuis, has been found in the Burgess Shale formation of British Columbia. 711 specimens of Yohoia are known from the Greater Phyllopod bed, where they comprise 1.35% of the community.[2] In 2015, Conway Morris et al. reported another species, Y. utahana, from the Marjum Formation, Utah.[1]

Description

Fossil specimens of Yohoia range in size from 7 to 30 mm,[1] they have a head shield which is followed by 13 flexible trunk segments, each represented by an arch-like tergite (dorsal plate). On both sides, the bottom side of the first 10 of these ended in backward-pointing tergopleurae (lateral extensions), where the tips are pointed in Y. tenuis and blunt in Y. utahana.[1] The last three segments were complete tubes, circling the entire trunk. At the end of the trunk was a paddle-like telson (tail).[3]

The head possess a pair of large eyes and a pair of great appendages at the front. The great appendages had a pronounced "elbow" and 4 distal segments ended in four long spines, looking rather like fingers. In the case of Y. tenuis, the appendages showing a "slender" and a "stout" morphotypes. Serrated fingers similar to Parapeytoia and Fortiforceps are evident in some specimens as well.[4] There were another 13 pairs of subequal appendages on the bottom of the body, 3 pairs below the head shield and 10 pairs below all but the last 3 trunk segments. Each of these appendages compose of a leg-like endopod and a flap-like exopods fringed with setae.[5][3]

Ecology

Yohoia is assumed to have been a mainly benthic (bottom-dwelling) creature that swam just above the muddy ocean floor, using its great appendages to scavenge or capture prey in a method similar to modern mantis shrimp.[3] The exopods are probably used for swimming and respiration.[6]

Classification

The genus and type species was first described in 1912 by Walcott, who considered it an anostracan crustacean.[7] Upon late 1990s, Yohoia is re-classify under Megacheira (great appendage arthropods),[8] a class of extinct arthropod which has controversial phylogenetic position either as stem chelicerates or a distinct lineage basal than both chelicerates and mandibulates.[9] Within megachierans, Yohoia is generally considered to be part of a clade including Haikoucaris and leanchoiliids, collectively known as Cheiromorpha.[10][11][12][13][14] Some recent studies suggest alternative positions, for example closer to other megacheirans[4][15] or Yohoia itself represent a distinct lineage[16][17].

See also

References

  1. ^ a b c d Morris, Simon Conway; Selden, Paul A.; Gunther, Glade; Jamison, Paul G.; Robison, Richard A. (2015). "New records of Burgess Shale-type taxa from the middle Cambrian of Utah". Journal of Paleontology. 89 (3): 411–423. Bibcode:2015JPal...89..411C. doi:10.1017/jpa.2015.26. ISSN 0022-3360. S2CID 55050961.
  2. ^ Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. Bibcode:2006Palai..21..451C. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022. S2CID 53646959.
  3. ^ a b c Haug, Joachim T.; Waloszek, Dieter; Maas, Andreas; Liu, Yu; Haug, Carolin (2012). "Functional morphology, ontogeny and evolution of mantis shrimp-like predators in the Cambrian". Palaeontology. 55 (2): 369–399. Bibcode:2012Palgy..55..369H. doi:10.1111/j.1475-4983.2011.01124.x. ISSN 1475-4983.
  4. ^ a b Zeng, Han; Zhao, Fangchen; Niu, Kecheng; Zhu, Maoyan; Huang, Diying (2020). "An early Cambrian euarthropod with radiodont-like raptorial appendages". Nature. 588 (7836): 101–105. Bibcode:2020Natur.588..101Z. doi:10.1038/s41586-020-2883-7. ISSN 1476-4687. PMID 33149303.
  5. ^ Briggs, Derek; Erwin, Douglas; Collier, Frederick. The Fossils of the Burgess Shale. Smithsonian Books (1994).
  6. ^ "Yohoia tenuis". The Burgess Shale. Retrieved 2026-01-27.
  7. ^ WALCOTT, C. D. (1912). "Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata". Smithsonian Miscellaneous Collections. 57: 145–228.
  8. ^ Hou, Xianguang; Bergstöm, Jan; Bergström, Jan (1997). Arthropods of the Lower Cambrian Chengjiang fauna, southwest China. Fossils and Strata. Oslo: Scandinavian Univ. Press. ISBN 978-82-00-37693-4.
  9. ^ Daley, Allison C.; Antcliffe, Jonathan B.; Drage, Harriet B.; Pates, Stephen (2018-05-22). "Early fossil record of Euarthropoda and the Cambrian Explosion". Proceedings of the National Academy of Sciences. 115 (21): 5323–5331. Bibcode:2018PNAS..115.5323D. doi:10.1073/pnas.1719962115. PMC 6003487. PMID 29784780.
  10. ^ Aria, Cédric; Caron, Jean-Bernard; Gaines, Robert (2015). "A large new leanchoiliid from the Burgess Shale and the influence of inapplicable states on stem arthropod phylogeny". Palaeontology. 58 (4): 629–660. Bibcode:2015Palgy..58..629A. doi:10.1111/pala.12161. ISSN 1475-4983.
  11. ^ Aria, Cédric; Caron, Jean-Bernard (2017). "Burgess Shale fossils illustrate the origin of the mandibulate body plan". Nature. 545 (7652): 89–92. Bibcode:2017Natur.545...89A. doi:10.1038/nature22080. ISSN 1476-4687. PMID 28445464.
  12. ^ Aria, Cédric; Caron, Jean-Bernard (2017-12-21). "Mandibulate convergence in an armoured Cambrian stem chelicerate". BMC Evolutionary Biology. 17 (1): 261. Bibcode:2017BMCEE..17..261A. doi:10.1186/s12862-017-1088-7. ISSN 1471-2148. PMC 5738823. PMID 29262772.
  13. ^ Aria, Cédric; Caron, Jean-Bernard (2017-12-21). "Mandibulate convergence in an armoured Cambrian stem chelicerate". BMC Evolutionary Biology. 17 (1): 261. Bibcode:2017BMCEE..17..261A. doi:10.1186/s12862-017-1088-7. ISSN 1471-2148. PMC 5738823. PMID 29262772.
  14. ^ Izquierdo-López, Alejandro; Caron, Jean-Bernard (2019). "A possible case of inverted lifestyle in a new bivalved arthropod from the Burgess Shale". Royal Society Open Science. 6 (11) 191350. Bibcode:2019RSOS....691350I. doi:10.1098/rsos.191350. ISSN 2054-5703. PMC 6894550. PMID 31827867.
  15. ^ Parry, Luke A.; Briggs, Derek E. G.; Ran, Ruixin; O'Flynn, Robert J.; Mai, Huijuan; Clark, Elizabeth G.; Liu, Yu (2024-12-02). "A pyritized Ordovician leanchoiliid arthropod". Current Biology. 34 (23): 5578–5586.e2. Bibcode:2024CBio...34.5578P. doi:10.1016/j.cub.2024.10.013. ISSN 0960-9822. PMID 39476836.
  16. ^ Zhai, Dayou; Williams, Mark; Siveter, David J.; Harvey, Thomas H. P.; Sansom, Robert S.; Gabbott, Sarah E.; Siveter, Derek J.; Ma, Xiaoya; Zhou, Runqing; Liu, Yu; Hou, Xianguang (2019-09-03). "Variation in appendages in early Cambrian bradoriids reveals a wide range of body plans in stem-euarthropods". Communications Biology. 2 (1): 329. doi:10.1038/s42003-019-0573-5. ISSN 2399-3642. PMC 6722085. PMID 31508504.
  17. ^ Aria, Cédric; Zhao, Fangchen; Zeng, Han; Guo, Jin; Zhu, Maoyan (2020-01-08). "Fossils from South China redefine the ancestral euarthropod body plan". BMC Evolutionary Biology. 20 (1): 4. Bibcode:2020BMCEE..20....4A. doi:10.1186/s12862-019-1560-7. ISSN 1471-2148. PMC 6950928. PMID 31914921.
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