Lenisicaris
{{Short description|Extinct genus of Cambrian radiodont}}
{{Automatic taxobox
| image = 20210513 Radiodonta frontal appendage Lenisicaris lupata.png
| image_caption = A reconstruction of L. lupata's frontal appendage
| image2 = Anomalocaris pennsylvanica KUMIP 298527.jpg
| image2_caption = A fossil of L. pennsylvanica
| fossil_range = Cambrian Stage 3 to Cambrian Stage 4 {{fossil range|521|509}}
| taxon = Lenisicaris
| authority = Wu et al, 2021
| type_species = {{extinct}}Lenisicaris lupata
| type_species_authority = Wu et al., 2021
| subdivision_ranks = Other species
| subdivision = * {{extinct}}L. pennsylvanica
(Resser, 1929)
| synonyms = * Anomalocaris pennsylvanica
(Resser, 1929)
}}
Lenisicaris, from Latin lēnis, meaning "smooth", and Ancient Greek καρίς (karís), meaning "shrimp", is an extinct Cambrian anomalocaridid radiodont, known from the Maotianshan Shales of China and the Kinzers Formation of Pennsylvania.{{cite journal |last1=Wu |first1=Yu |last2=Ma |first2=Jiaxin |last3=Lin |first3=Weiliang |last4=Sun |first4=Ao |last5=Zhang |first5=Xingliang |last6=Fu |first6=Dongjing |title=New anomalocaridids (Panarthropoda: Radiodonta) from the lower Cambrian Chengjiang Lagerstätte: Biostratigraphic and paleobiogeographic implications |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=1 May 2021 |volume=569 |doi=10.1016/j.palaeo.2021.110333 |bibcode=2021PPP...56910333W |s2cid=233565727 |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018221001188|url-access=subscription }}
Discovery and naming
In 1929, American paleontologist Charles E. Resser described a poorly preserved arthropod fossil from the Kinzers Formation. He thought this specimen represented a new species of Anomalocaris, so it was classified as Anomalocaris pennsylvanica, which makes it the second radiodont species ever described. Numerous specimens have later been referred to this species, but the majority of them were subsequently assigned to different taxa of radiodonts.{{Cite journal| doi = 10.1017/S0016756818000547| volume = 156| issue = 7| pages = 1233–1246| last1 = Pates| first1 = Stephen| last2 = Daley| first2 = Allison C.| title = The Kinzers Formation (Pennsylvania, USA): the most diverse assemblage of Cambrian Stage 4 radiodonts| journal = Geological Magazine| date = 2019 | bibcode = 2019GeoM..156.1233P| s2cid = 134299859| url = https://www.cambridge.org/core/product/identifier/S0016756818000547/type/journal_article}}{{cite journal |vauthors=Pates S, Daley AC, Edgecombe GD, Cong P, Lieberman BS |year=2019 |title=Systematics, preservation and biogeography of radiodonts from the southern Great Basin, USA, during the upper Dyeran (Cambrian Series 2, Stage 4) |url=https://serval.unil.ch/notice/serval:BIB_29DFB7FB5010 |journal=Papers in Palaeontology |language=en |volume=7 |pages=235–262 |doi=10.1002/spp2.1277|s2cid=204260554 |issn=2056-2799 |url-access=subscription }} Only three specimens are now confidently included within this species.
L. pennsylvanica was long thought to be a species of Anomalocaris, until a 2021 study assigned it to the genus Lenisicaris on the basis of frontal appendage morphology similar to that of the type species, L. lupata. The specific name lupata derives from the combination of the word "lupus" and "fanga", meaning large sharp wolf tooth, based on the shape of the endites resembling wolf fangs.{{cite journal |last1=Wu |first1=Yu |last2=Ma |first2=Jiaxin |last3=Lin |first3=Weiliang |last4=Sun |first4=Ao |last5=Zhang |first5=Xingliang |last6=Fu |first6=Dongjing |title=New anomalocaridids (Panarthropoda: Radiodonta) from the lower Cambrian Chengjiang Lagerstätte: Biostratigraphic and paleobiogeographic implications |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=1 May 2021 |volume=569 |doi=10.1016/j.palaeo.2021.110333 |bibcode=2021PPP...56910333W |s2cid=233565727 |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018221001188|url-access=subscription }}
Description
Lenisicaris is only known from frontal appendages, though these specimens have several distinguishing traits, most noticeably the lack of auxiliary spines.{{cite journal |last1=Potin |first1=Gaëtan J.-M. |last2=Daley |first2=Allison C. |title=The significance of Anomalocaris and other Radiodonta for understanding paleoecology and evolution during the Cambrian explosion |journal=Frontiers in Earth Science |date=2023 |volume=11 |doi=10.3389/feart.2023.1160285 |doi-access=free |bibcode=2023FrEaS..1160285P |issn=2296-6463}} The type species L. lupata has smaller, triangular endites, closely resembling those of Anomalocaris. The other species L. pennsylvanica (formerly described as a species of Anomalocaris{{cite journal|last1=Resser|first1=Charles E.|year=1929|title=New Lower and Middle Cambrian Crustacea|journal=Proceedings of the United States National Museum|volume=76|issue=2806|pages=1–18|doi=10.5479/si.00963801.76-2806.1|url=https://repository.si.edu/bitstream/handle/10088/15802/USNMP-76_2806_1929.pdf}}) has larger and more rectangular endites, with those on odd-numbered podomeres being smaller.{{cite journal |last1=Wu |first1=Yu |last2=Ma |first2=Jiaxin |last3=Lin |first3=Weiliang |last4=Sun |first4=Ao |last5=Zhang |first5=Xingliang |last6=Fu |first6=Dongjing |title=New anomalocaridids (Panarthropoda: Radiodonta) from the lower Cambrian Chengjiang Lagerstätte: Biostratigraphic and paleobiogeographic implications |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=1 May 2021 |volume=569 |doi=10.1016/j.palaeo.2021.110333 |bibcode=2021PPP...56910333W |s2cid=233565727 |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018221001188|url-access=subscription }}