| 词条 | Sanctacaris |
| 释义 |
| image = Sanctacaris.jpg | image2 = SanctacarisUncata-ROM-June11-10.jpg | fossil_range = Middle Cambrian | regnum = Animalia | phylum = Arthropoda | subphylum = Chelicerata | familia = †Sanctacarididae | genus = †Sanctacaris | genus_authority = Briggs & Collins, 1988 | species = †S. uncata | binomial = Sanctacaris uncata | binomial_authority = Briggs & Collins, 1988 }}Sanctacaris is a Middle Cambrian arthropod from the Burgess Shale of British Columbia. It was most famously regarded as a primitive chelicerate, a group which includes spiders and scorpions, although subsequent phylogenetic studies have not always supported this conclusion; it is best accommodated in the arachnate clade (i.e. as a stem-group chelicerate).[1] Sanctacaris specimens range from 46 to 93 mm in length.[2] The head bears five pairs of grasping appendages and a sixth pair of large separate appendages. The grasping appendages each bear a short antenna-like second appendage. There are 11 body segments, each with a pair of walking legs and gills. There is a broad, flat paddle-like telson. Originally Sanctacaris was called informally 'Santa Claws'. Its Latin name translates as "saintly crab".{{fotbs}} Unlike most other Burgess forms, Sanctacaris is not present in Charles Walcott's 1909 quarry and was discovered at a different level by Desmond Collins in 1980–1981.{{fotbs}} References1. ^{{cite journal |author= G. E. Budd, S. Jensen |year=2000 |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 |doi=10.1017/s000632310000548x}} 2. ^{{cite journal |author=Briggs, Derek E. G. |authorlink=Derek Briggs |author2=Collins, Desmond |year=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 |accessdate=April 4, 2010 |format=PDF |deadurl=yes |archiveurl=https://web.archive.org/web/20110716060204/http://palaeontology.palass-pubs.org/pdf/Vol%2031/Pages%20779-798.pdf |archivedate=July 16, 2011 |df= }} External links
3 : Prehistoric chelicerates|Burgess Shale fossils|Fossil taxa described in 1988 |
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