Parapeytoia

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Parapeytoia
Temporal range: Cambrian Stage 3–Cambrian Stage 4
Parapeytoia yunnanensis NIGPAS 115334 (cropped).jpg
Holotype of Parapeytoia yunnanensis, part and counterpart
20191021 Parapeytoia yunnanensis ventral structures.png
Ventral structures of the same species
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Arthropoda
Class: Megacheira
Family: Jianfengiidae
Genus: Parapeytoia
Hou, Bergström & Ahlberg, 1995 [1]
Type species
Parapeytoia yunnanensis
Hou, Bergstrom & Ahlberg, 1995 [1]

Parapeytoia is a genus of Cambrian arthropod. The type and only described species is Parapeytoia yunnanensis, which lived over 518 million years ago [2] (Cambrian Stage 3) in the Maotianshan shales of Yunnan, China. Unidentified fossils from the same genus have also been discovered from the nearby Wulongqing Formation (Cambrian Stage 4). [3]

Contents

Classification

Initially, Parapeytoia was interpreted as a radiodont ("anomalocaridid" at that time) dinocaridid with legs alongside Cucumericrus , [1] purported to be an indicator that radiodonts might have legs underneath their body flaps in general, comparable to Pambdelurion . [4] With the combination of megacheiran and presumably radiodont features (see text), it was also suggested to be an intermediate form between the two taxa. [5] [6] However, later studies revealed it was most likely nested within megacheira, [7] [8] [9] [10] [11] [12] [13] [14] and the group as a whole was no longer thought to have originated from radiodonts. [15] Within megacheira, Parapeytoia was possibly closest to the multisegmented (with over 20 trunk segments) taxa like Fortiforceps and Jianfengia , united under the family Jianfengiidae. [14]

Description

Interpretations on Parapeytoia yunnanensis as a radiodont (A) and jianfengiid megacheiran (B) respectively. Red parts indicating suggested radiodont-like features with questionable affinity. Dark grey indicating other structures unambiguously belong to this species. 20191021 Parapeytoia yunnanensis interpretation.png
Interpretations on Parapeytoia yunnanensis as a radiodont (A) and jianfengiid megacheiran (B) respectively. Red parts indicating suggested radiodont-like features with questionable affinity. Dark grey indicating other structures unambiguously belong to this species.

Parapeytoia is known from a few incomplete fossil materials with part of its ventral structures preserved. The frontmost appendages were a pair of great appendages consisting of a robust peduncle and 4 distal segments with a serrated spine on each of them, a feature shared by some other megacheirans such as Yohoia and Fortiforceps . [16] [17] Behind the great appendages were 2 or 3 pairs of short appendages, and numerous pairs of well-developed biramous appendages, each formed by a basipod with a spiny gnathobase, lobe-like exopod and leg-like endopod with 8 segments. A narrow, hourglass-like sternite was associated between each of those appendages. [1]

Some features originally interpreted as radiodont-like are now considered questionable. Radial sclerites interpreted as Parapeytoia mouthparts (oral cone) have since been assigned to another genus of animal, Omnidens . [18] While some subsequent studies suggest those features are genuine, they most likely represent ancestral traits originating from more basal arthropods instead of any indicators of radiodont affinities. [19] This is the case for the gnathobases, [20] and the presence of arthropodized endopods underneath the purported body flaps (exopods), which conflict with the radiodont trunk appendages as well (the radiodont ventral body flaps are most likely homologous to euarthropod endopods). [13]

Parapeytoia was probably a benthic feeder, spending most of its time on the ocean floor hunting (or possibly scavenging) for prey. [12]

References

  1. 1 2 3 4 Xian-Guang, Hou; Bergström, Jan; Ahlberg, Per (1995-09-01). "Anomalocaris and other large animals in the lower Cambrian Chengjiang fauna of southwest China". GFF. 117 (3): 163–183. Bibcode:1995GFF...117..163X. doi:10.1080/11035899509546213. ISSN   1103-5897.
  2. Yang, Chuan; Li, Xian-Hua; Zhu, Maoyan; Condon, Daniel J.; Chen, Junyuan (2018). "Geochronological constraint on the Cambrian Chengjiang biota, South China". Journal of the Geological Society. 175 (4): 659–666. Bibcode:2018JGSoc.175..659Y. doi:10.1144/jgs2017-103. ISSN   0016-7649. S2CID   135091168.
  3. Hu, ShiXue; Zhu, MaoYan; Steiner, Michael; Luo, HuiLin; Zhao, FangChen; Liu, Qi (2010-12-01). "Biodiversity and taphonomy of the Early Cambrian Guanshan biota, eastern Yunnan" . Science China Earth Sciences. 53 (12): 1765–1773. Bibcode:2010ScChD..53.1765H. doi:10.1007/s11430-010-4086-9. ISSN   1869-1897. S2CID   128882075.
  4. Xianguang, Hou; Jan, Jan Bergström; Jiayu, In Rong; Zongjie, Fang; Zhanghe, Zhou; Renbin, Zhan; Xiangdong, Wang; (eds, Yuan Xunlai et al. (2006). Dinocaridids - anomalous arthropods or arthropod-like worms?.
  5. Budd, Graham E. (2002). "A palaeontological solution to the arthropod head problem" . Nature. 417 (6886): 271–275. Bibcode:2002Natur.417..271B. doi:10.1038/417271a. ISSN   1476-4687. PMID   12015599. S2CID   4310080.
  6. Chen, Junyuan; Waloszek, Dieter; Maas, Andreas (2004). "A new 'great-appendage' arthropod from the Lower Cambrian of China and homology of chelicerate chelicerae and raptorial antero-ventral appendages" . Lethaia. 37 (1): 3–20. Bibcode:2004Letha..37....3C. doi:10.1080/00241160410004764. ISSN   0024-1164.
  7. Daley, Allison C.; Budd, Graham E.; Caron, Jean-Bernard; Edgecombe, Gregory D.; Collins, Desmond (2009-03-20). "The Burgess Shale Anomalocaridid Hurdia and Its Significance for Early Euarthropod Evolution". Science. 323 (5921): 1597–1600. Bibcode:2009Sci...323.1597D. doi:10.1126/science.1169514. ISSN   0036-8075. PMID   19299617. S2CID   206517995.
  8. Stein, Martin (2010-03-01). "A new arthropod from the Early Cambrian of North Greenland, with a 'great appendage'-like antennula" . Zoological Journal of the Linnean Society. 158 (3): 477–500. doi:10.1111/j.1096-3642.2009.00562.x. ISSN   0024-4082.
  9. Legg, David A.; Sutton, Mark D.; Edgecombe, Gregory D.; Caron, Jean-Bernard (2012). "Cambrian bivalved arthropod reveals origin of arthrodization". Proceedings of the Royal Society B: Biological Sciences. 279 (1748): 4699–4704. doi:10.1098/rspb.2012.1958. ISSN   0962-8452. PMC   3497099 . PMID   23055069.
  10. Legg, David A.; Sutton, Mark D.; Edgecombe, Gregory D. (2013-09-30). "Arthropod fossil data increase congruence of morphological and molecular phylogenies". Nature Communications. 4 (1): 2485. Bibcode:2013NatCo...4.2485L. doi:10.1038/ncomms3485. ISSN   2041-1723. PMID   24077329.
  11. Daley, Allison C.; Edgecombe, Gregory D. (2014). "Morphology of Anomalocaris canadensis from the Burgess Shale". Journal of Paleontology. 88 (1): 68–91. Bibcode:2014JPal...88...68D. doi:10.1666/13-067. ISSN   0022-3360. S2CID   86683798.
  12. 1 2 Xian-Guang, Hou; Siveter, David J.; Siveter, Derek J.; Aldridge, Richard J.; Pei-Yun, Cong; Gabbott, Sarah E.; Xiao-Ya, Ma; Purnell, Mark A.; Williams, Mark (2017-04-24). The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life. John Wiley & Sons. ISBN   9781118896389.
  13. 1 2 Van Roy, Peter; Daley, Allison C.; Briggs, Derek E. G. (2015-06-04). "Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps". Nature. 522 (7554): 77–80. Bibcode:2015Natur.522...77V. doi:10.1038/nature14256. ISSN   1476-4687. PMID   25762145. S2CID   205242881.
  14. 1 2 Aria, Cédric; Zhao, Fangchen; Zeng, Han; Guo, Jin; Zhu, Maoyan (2020). "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.
  15. Ortega-Hernández, Javier; Janssen, Ralf; Budd, Graham E. (2017-05-01). "Origin and evolution of the panarthropod head – A palaeobiological and developmental perspective". Arthropod Structure & Development. Evolution of Segmentation. 46 (3): 354–379. Bibcode:2017ArtSD..46..354O. doi: 10.1016/j.asd.2016.10.011 . ISSN   1467-8039. PMID   27989966.
  16. Haug, Joachim T.; Waloszek, Dieter; Maas, Andreas; Liu, Yu; Haug, Carolin (March 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 . S2CID   82841481.
  17. 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. S2CID   226248177.
  18. Hou, Xianguang; Bergström, Jan; Jie, Yang (2006). "Distinguishing anomalocaridids from arthropods and priapulids". Geological Journal. 41 (3–4): 259–269. Bibcode:2006GeolJ..41..259X. doi:10.1002/gj.1050. S2CID   83582128.
  19. Budd, Graham E. (2021-05-01). "The origin and evolution of the euarthropod labrum". Arthropod Structure & Development. 62: 101048. Bibcode:2021ArtSD..6201048B. doi:10.1016/j.asd.2021.101048. ISSN   1467-8039. PMID   33862532.
  20. Cong, Peiyun; Daley, Allison C.; Edgecombe, Gregory D.; Hou, Xianguang (2017). "The functional head of the Cambrian radiodontan (stem-group Euarthropoda) Amplectobelua symbrachiata". BMC Evolutionary Biology. 17 (1): 208. Bibcode:2017BMCEE..17..208C. doi: 10.1186/s12862-017-1049-1 . ISSN   1471-2148. PMC   5577670 . PMID   28854872.