Haikoucaris
{{Short description|Extinct genus of arthropods}}
{{Speciesbox
| fossil_range = {{fossil range|518}}
| image = 20191020 Haikoucaris ercaiensis.png
| image_caption = Reconstruction of Haikoucaris ercaiensis
| genus = Haikoucaris
| parent_authority = Chen et al., 2004
| species = ercaiensis
| authority = Chen et al., 2004
| display_parents = 2
}}
Haikoucaris is a genus of megacheiran arthropod that contains the single species Haikoucaris ercaiensis. It was discovered in the Cambrian Chengjiang biota of China.{{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://onlinelibrary.wiley.com/doi/abs/10.1080/00241160410004764|journal=Lethaia|language=en|volume=37|issue=1|pages=3–20|doi=10.1080/00241160410004764|bibcode=2004Letha..37....3C |issn=1502-3931}}
Morphology
File:Zhejiang Geological Museum 20240804 122150.jpg
Haikoucaris measured about 38 mm in body length. The elongated body compose of a semicircular head shield, 13 trunk tergites and presumely a short, spine-like telson.{{Cite book|last1=Xian-Guang|first1=Hou|url=https://books.google.com/books?id=X61RDgAAQBAJ&q=Haikoucaris&pg=PA188|title=The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life|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=2017-03-08|publisher=John Wiley & Sons|isbn=978-1-118-89631-0|language=en}} The head possess a pair of unstalked eyes, a pair well-developed great appendages, as well as 3 more appendage pairs of unknown detail. Each of the great appendage consists of a 2-segmented peduncle and a 3-segmented claw. Each of the trunk segment possess a pair of biramus appendages that each comprising a leaf-shaped exopod and a possibly 7-segmented endopod.
Paleoecology
Haikoucaris may have been a predator, with its great appendages and exopod suggested to be used for hunting and swimming respectively.
Taxonomy
Within megacheirans, Haikoucaris is generally accepted to be a member of the clade Cheiromorpha alongside Yohoia and Leanchoiliidae.{{Cite journal|last1=Aria|first1=Cédric|last2=Caron|first2=Jean-Bernard|last3=Gaines|first3=Robert|date=2015|title=A large new leanchoiliid from the Burgess Shale and the influence of inapplicable states on stem arthropod phylogeny|journal=Palaeontology|language=en|volume=58|issue=4|pages=629–660|doi=10.1111/pala.12161|s2cid=86443516 |issn=1475-4983|doi-access=free|bibcode=2015Palgy..58..629A }}{{Cite journal|last1=Izquierdo-López|first1=Alejandro|last2=Caron|first2=Jean-Bernard|date=2019|title=A possible case of inverted lifestyle in a new bivalved arthropod from the Burgess Shale|url= |journal=Royal Society Open Science|volume=6|issue=11|pages=191350|doi=10.1098/rsos.191350|pmc=6894550|pmid=31827867|bibcode=2019RSOS....691350I }}{{Cite journal|last1=Aria|first1=Cédric|last2=Caron|first2=Jean-Bernard|date=2017-12-21|title=Mandibulate convergence in an armoured Cambrian stem chelicerate|url= |journal=BMC Evolutionary Biology|volume=17|issue=1|pages=261|doi=10.1186/s12862-017-1088-7|issn=1471-2148|pmc=5738823|pmid=29262772 |doi-access=free |bibcode=2017BMCEE..17..261A }}{{Cite journal|last1=Aria|first1=Cédric|last2=Zhao|first2=Fangchen|last3=Zeng|first3=Han|last4=Guo|first4=Jin|last5=Zhu|first5=Maoyan|date=December 2020|title=Fossils from South China redefine the ancestral euarthropod body plan|url= |journal=BMC Evolutionary Biology|language=en|volume=20|issue=1|pages=4|doi=10.1186/s12862-019-1560-7|issn=1471-2148|pmc=6950928|pmid=31914921 |doi-access=free |bibcode=2020BMCEE..20....4A }}
See also
{{Portal box|Paleontology|Arthropods}}