Editing Sanctacaris

{{Short description|Extinct genus of arthropods}}
{{Speciesbox
| image = 20191019 Sanctacaris uncata.png
| image2 = SanctacarisUncata-ROM-June11-10.jpg
| image_caption = Life restoration
| image2_caption = Holotype specimen
| fossil_range = [[Middle Cambrian]]
| genus = Sanctacaris
| parent_authority = Briggs & Collins, 1988
| species = uncata
| authority = Briggs & Collins, 1988
}}

'''''Sanctacaris''''' is a [[Middle Cambrian]] [[arthropod]] from the [[Burgess Shale]] of [[British Columbia]]. It was most famously regarded as a [[crown group|stem-group]] [[chelicerata|chelicerate]], a group which includes [[horseshoe crabs]], [[spider]]s and [[scorpion]]s, although subsequent [[phylogenetic]] studies have not always supported this conclusion.<ref name="Budd2000">{{cite journal | vauthors = Budd GE, Jensen S | title = A critical reappraisal of the fossil record of the bilaterian phyla | journal = Biological Reviews of the Cambridge Philosophical Society | volume = 75 | issue = 2 | pages = 253–95 | date = May 2000 | pmid = 10881389 | doi = 10.1017/s000632310000548x }}</ref> Its chelicerate affinities regain support in later observations,<ref name="Legg_2014">{{cite journal | vauthors = Legg DA | title = Sanctacaris uncata: the oldest chelicerate (Arthropoda) | journal = Die Naturwissenschaften | volume = 101 | issue = 12 | pages = 1065–73 | date = December 2014 | pmid = 25296691 | doi = 10.1007/s00114-014-1245-4 | bibcode = 2014NW....101.1065L | s2cid = 253637303 }}</ref><ref name="Aria_2017">{{cite journal |vauthors=Aria C, Caron JB |date=December 2017 |title=Mandibulate convergence in an armoured Cambrian stem chelicerate |journal=BMC Evolutionary Biology |volume=17 |issue=1 |pages=261 |doi=10.1186/s12862-017-1088-7 |pmc=5738823 |pmid=29262772 |doi-access=free }}</ref> alongside the reassignment of ''[[Habelia]] optata'' as a sanctacaridid-related basal chelicerate.<ref name="Aria_2017" /> It has been placed as a member of the extinct family Sanctacarididae alongside ''[[Wisangocaris]]'' and ''[[Utahcaris]]''.<ref name="Aria_2017" />

''Sanctacaris'' specimens range from 46 to 93&nbsp;mm in length.<ref name="Briggs_1988">{{cite journal | vauthors = Briggs DE, Collins D |author-link1 = Derek Briggs |date= August 1988 |title=A Middle Cambrian chelicerate from Mount Stephen, British Columbia |journal=Palaeontology |volume=31 |issue=3 |pages=779–798 |url=http://palaeontology.palass-pubs.org/pdf/Vol%2031/Pages%20779-798.pdf |access-date=April 4, 2010 |url-status=usurped |archive-url= https://web.archive.org/web/20110716060204/http://palaeontology.palass-pubs.org/pdf/Vol%2031/Pages%20779-798.pdf |archive-date=July 16, 2011 }}</ref> The head bears five pairs of grasping appendages (corresponding to chelicerate's [[pedipalps]] and walking legs) and a sixth pair of posterior appendages (correspond to horseshoe crab's chilaria).<ref name="Briggs_1988" /> The grasping appendages each bear an [[antenna (biology)|antenna]]-like exopods.<ref name="Legg_2014" /> There are 11 body segments, with the former 10 each bearing a pair of [[Arthropod leg|biramous]] appendages with flap-like exopod and reduced leg-like endopod. There is a broad, flat paddle-like [[telson]].<ref name="Briggs_1988" />

Originally ''Sanctacaris'' was called informally 'Santa Claws'. Its Latin name translates as "saintly crab".<ref name="fotbs" /> Unlike most other Burgess forms, ''Sanctacaris'' is not present in [[Charles Doolittle Walcott|Charles Walcott]]'s 1909 quarry and was discovered at a different level by Desmond Collins in 1980–1981.<ref name=fotbs>{{cite book | year = 1995 | vauthors = Briggs DE, Erwin DH, Collier FJ | author-link1 = Derek Briggs | title = Fossils of the [[Burgess Shale]] | isbn = 1-56098-659-X | publisher = Smithsonian Institution Press | location = Washington | oclc = 231793738 }}</ref>

== Etymology ==
The generic name "''Sanctacaris'' " is a compound of the Latin words "sanctus" (saint or sacred) and "caris" (meaning crab or shrimp, a common suffix used in aquatic arthropods).<ref name="Briggs_1988" /> The specific name of the type species ''"uncata'' " means "claws" in Latin and is named after the claw-shaped appendages on the head of this species.<ref name="Briggs_1988" /> The name "saint claws" refers to [[Santa Claus]], which was the field name used to refer to ''Sanctacaris''.<ref name="Briggs_1988" />

== Ecology ==
The robust gnathobases, alongside the fact that fellow sanctacaridid ''[[Wisangocaris]]'' has been found with trilobite fragments in its stomach, has led to suggestions that ''Sanctacaris'' was [[durophagous]], feeding on hard shelled organisms.<ref name="Aria_2017" />

== See also ==

* [[Paleobiota of the Burgess Shale]]

== References ==
{{Reflist}}

== External links ==
* {{Cite web|date=2011|title=''Sanctacaris uncata''|work=Burgess Shale Fossil Gallery|publisher=Virtual Museum of Canada|url=http://burgess-shale.rom.on.ca/en/fossil-gallery/view-species.php?id=109|archive-url=https://web.archive.org/web/20201112025257/http://burgess-shale.rom.on.ca/en/fossil-gallery/view-species.php?id=109|archive-date=2020-11-12|url-status=dead|access-date=2023-01-21}}

{{Taxonbar|from1=Q20672511|from2=Q2718204}}

[[Category:Prehistoric chelicerates]]
[[Category:Burgess Shale fossils]]
[[Category:Fossil taxa described in 1988]]
[[Category:Cambrian genus extinctions]]