:en:Parapeytoia

Initially, Parapeytoia was interpreted as a radiodont ("anomalocaridid" at that time) dinocaridid with legs alongside Cucumericrus,{{Cite journal|last1=Xian-Guang|first1=Hou|last2=Bergström|first2=Jan|last3=Ahlberg|first3=Per|date=1995-09-01|title=Anomalocaris and other large animals in the lower Cambrian Chengjiang fauna of southwest China|journal=GFF|volume=117|issue=3|pages=163–183|doi=10.1080/11035899509546213|bibcode=1995GFF...117..163X |issn=1103-5897}} purported to be an indicator that radiodonts might have legs underneath their body flaps in general, comparable to Pambdelurion.Xianguang, Hou; Jan, Jan Bergström; Jiayu, In Rong; Zongjie, Fang; Zhanghe, Zhou; Renbin, Zhan; Xiangdong, Wang; (eds, Yuan Xunlai et al. (2006). [http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.693.5869 Dinocaridids - anomalous arthropods or arthropod-like worms?]. With the combination of megacheiran and presumably radiodont features (see text), it was also suggest to be an intermediate form between the two taxa.{{Cite journal |last=Budd |first=Graham E. |date=2002 |title=A palaeontological solution to the arthropod head problem |url=https://www.nature.com/articles/417271a |journal=Nature |language=en |volume=417 |issue=6886 |pages=271–275 |doi=10.1038/417271a |pmid=12015599 |bibcode=2002Natur.417..271B |s2cid=4310080 |issn=1476-4687}}{{Cite journal |last1=Chen |first1=Junyuan |last2=Waloszek |first2=Dieter |last3=Maas |first3=Andreas |date=2004 |title=A new 'great-appendage' arthropod from the Lower Cambrian of China and homology of chelicerate chelicerae and raptorial antero-ventral appendages |url=https://www.idunn.no/doi/10.1080/00241160410004764 |journal=Lethaia |language=en |volume=37 |issue=1 |pages=3–20 |doi=10.1080/00241160410004764 |bibcode=2004Letha..37....3C |issn=0024-1164}} However, later studies reveal it most likely nested within megacheirans,{{Cite journal|last1=Daley|first1=Allison C.|last2=Budd|first2=Graham E.|last3=Caron|first3=Jean-Bernard|last4=Edgecombe|first4=Gregory D.|last5=Collins|first5=Desmond|date=2009-03-20|title=The Burgess Shale Anomalocaridid Hurdia and Its Significance for Early Euarthropod Evolution|journal=Science|volume=323|issue=5921|pages=1597–1600|doi=10.1126/science.1169514|issn=0036-8075|pmid=19299617|bibcode=2009Sci...323.1597D|s2cid=206517995}}{{Cite journal|last=Stein|first=Martin|date=2010-03-01|title=A new arthropod from the Early Cambrian of North Greenland, with a 'great appendage'-like antennula|url=https://academic.oup.com/zoolinnean/article/158/3/477/3798454|journal=Zoological Journal of the Linnean Society|volume=158|issue=3|pages=477–500|doi=10.1111/j.1096-3642.2009.00562.x|issn=0024-4082}}{{Cite journal |last1=Legg |first1=David A. |last2=Sutton |first2=Mark D. |last3=Edgecombe |first3=Gregory D. |last4=Caron |first4=Jean-Bernard |date=2012 |title=Cambrian bivalved arthropod reveals origin of arthrodization |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=279 |issue=1748 |pages=4699–4704 |doi=10.1098/rspb.2012.1958 |issn=0962-8452 |pmc=3497099 |pmid=23055069}}{{Cite journal |last1=Legg |first1=David A. |last2=Sutton |first2=Mark D. |last3=Edgecombe |first3=Gregory D. |date=2013-09-30 |title=Arthropod fossil data increase congruence of morphological and molecular phylogenies |url=https://www.nature.com/articles/ncomms3485 |journal=Nature Communications |language=en |volume=4 |issue=1 |pages=2485 |doi=10.1038/ncomms3485 |pmid=24077329 |bibcode=2013NatCo...4.2485L |issn=2041-1723}}{{Cite journal|last1=Daley|first1=Allison C.|last2=Edgecombe|first2=Gregory D.|title=Morphology of Anomalocaris canadensis from the Burgess Shale|url=https://www.academia.edu/6947803|journal=Journal of Paleontology|volume=88|issue=1|pages=68–91|issn=0022-3360|doi=10.1666/13-067|year=2014|bibcode=2014JPal...88...68D |s2cid=86683798}}{{Cite book|url=https://books.google.com/books?id=2YWhDgAAQBAJ&q=parapeytoia&pg=PA184|title=The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life|last1=Xian-Guang|first1=Hou|last2=Siveter|first2=David J.|last3=Siveter|first3=Derek J.|last4=Aldridge|first4=Richard J.|last5=Pei-Yun|first5=Cong|last6=Gabbott|first6=Sarah E.|last7=Xiao-Ya|first7=Ma|last8=Purnell|first8=Mark A.|last9=Williams|first9=Mark|date=2017-04-24|publisher=John Wiley & Sons|isbn=9781118896389}}{{Cite journal|last1=Van Roy|first1=Peter|last2=Daley|first2=Allison C.|last3=Briggs|first3=Derek E. G.|date=2015-06-04|title=Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps|journal=Nature|volume=522|issue=7554|pages=77–80|doi=10.1038/nature14256|pmid=25762145|bibcode=2015Natur.522...77V|s2cid=205242881|issn=1476-4687}}{{Cite journal |last1=Aria |first1=Cédric |last2=Zhao |first2=Fangchen |last3=Zeng |first3=Han |last4=Guo |first4=Jin |last5=Zhu |first5=Maoyan |date=2020 |title=Fossils from South China redefine the ancestral euarthropod body plan |journal=BMC Evolutionary Biology |volume=20 |issue=1 |pages=4 |doi=10.1186/s12862-019-1560-7 |doi-access=free |issn=1471-2148 |pmc=6950928 |pmid=31914921|bibcode=2020BMCEE..20....4A }} and megacheirans was no longer thought to be originated from radiodonts since than.{{Cite journal|last1=Ortega-Hernández|first1=Javier|last2=Janssen|first2=Ralf|last3=Budd|first3=Graham E.|date=2017-05-01|title=Origin and evolution of the panarthropod head – A palaeobiological and developmental perspective|journal=Arthropod Structure & Development|series=Evolution of Segmentation|volume=46|issue=3|pages=354–379|doi=10.1016/j.asd.2016.10.011|pmid=27989966|issn=1467-8039|doi-access=free|bibcode=2017ArtSD..46..354O }} Within megacheirans, Parapeytoia possibly closest to the multisegmented (with over 20 trunk segments) taxa like Fortiforceps and Jianfengia, united under the family Jianfengiidae.

File:20191021 Parapeytoia yunnanensis interpretation.png (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.|left]]

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 that form by a robust peduncle and 4 distal segments with serrated spine on each of them, a feature shared by some other megacheirans such as Yohoia and Fortiforceps.{{Cite journal |last1=Haug |first1=Joachim T. |last2=Waloszek |first2=Dieter |last3=Maas |first3=Andreas |last4=Liu |first4=Yu |last5=Haug |first5=Carolin |date=March 2012 |title=Functional morphology, ontogeny and evolution of mantis shrimp-like predators in the Cambrian |journal=Palaeontology |volume=55 |issue=2 |pages=369–399 |doi=10.1111/j.1475-4983.2011.01124.x |s2cid=82841481|doi-access=free |bibcode=2012Palgy..55..369H }}{{Cite journal |last1=Zeng |first1=Han |last2=Zhao |first2=Fangchen |last3=Niu |first3=Kecheng |last4=Zhu |first4=Maoyan |last5=Huang |first5=Diying |date=2020 |title=An early Cambrian euarthropod with radiodont-like raptorial appendages |url=https://www.nature.com/articles/s41586-020-2883-7 |journal=Nature |language=en |volume=588 |issue=7836 |pages=101–105 |doi=10.1038/s41586-020-2883-7 |pmid=33149303 |bibcode=2020Natur.588..101Z |s2cid=226248177 |issn=1476-4687}} 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 spiny gnathobase, lobe-like exopod and leg-like endopod with 8 segments. A narrow, hourglass-like sternite associated between each of those appendages.

Some features originally interpreted as radiodont-like are more or less questionable, such as radial sclerites interpreted as its mouthparts (oral cone) have since been assigned to another genus of animal, Omnidens.{{Cite journal|last1=Hou|first1=Xianguang|last2=Bergström|first2=Jan|last3=Jie|first3=Yang|year=2006|title=Distinguishing anomalocaridids from arthropods and priapulids|journal=Geological Journal|volume=41|issue=3–4|pages=259–269|doi=10.1002/gj.1050|bibcode=2006GeolJ..41..259X |s2cid=83582128 }} While some subsequent studies suggest those features are genuine, it most likely represent ancestral traits originated from more basal arthropods instead of any indicators of radiodont affinities.{{Cite journal |last=Budd |first=Graham E. |date=2021-05-01 |title=The origin and evolution of the euarthropod labrum |url=https://www.sciencedirect.com/science/article/pii/S1467803921000220 |journal=Arthropod Structure & Development |volume=62 |pages=101048 |doi=10.1016/j.asd.2021.101048 |bibcode=2021ArtSD..6201048B |issn=1467-8039}} The same goes with gnathobases,{{Cite journal |last1=Cong |first1=Peiyun |last2=Daley |first2=Allison C. |last3=Edgecombe |first3=Gregory D. |last4=Hou |first4=Xianguang |date=2017 |title=The functional head of the Cambrian radiodontan (stem-group Euarthropoda) Amplectobelua symbrachiata |journal=BMC Evolutionary Biology |volume=17 |issue=1 |pages=208 |doi=10.1186/s12862-017-1049-1 |doi-access=free |issn=1471-2148 |pmc=5577670 |pmid=28854872|bibcode=2017BMCEE..17..208C }} and the presence of arthropodized endopods underneath the purported body flaps (exopods) conflict with the component of radiodont trunk appendages as well (the radiodont ventral body flaps are most likely homologous to euarthropod endopods).

Parapeytoia was in all likelihood a benthic feeder, spending most of its time on the ocean floor hunting (or possibly scavenging) for prey.

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{{Reflist}}

• [http://www.museunacional.ufrj.br/mndi/Aracnologia/pdfliteratura/2006e%20S%20Hou%20&%20Bergstr%2B%C2m%20Dinocaridids.pdf Dinocaridids: anomalous arthropods or arthropod-like worms? by Hou Xianguang & Jan Bergström 2006] arguing that this genus is a dinocaridid

• [http://www.trilobites.info/species2.html An Anomalocarid With Legs?]

{{Megacheira}}

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Category:Megacheira

Category:Cambrian arthropods

Category:Maotianshan shales fossils

Category:Prehistoric arthropod genera

Category:Cambrian genus extinctions