Chasmataspis
{{Short description|Extinct genus of arthropods}}
{{Automatic taxobox
| name = Chasmataspis
| fossil_range = {{Fossil range |Darriwilian}}
| image = Chasmataspis laurencii USNM PAL 125099.jpg
| image_caption = Holotype specimen
| image2 = 20200606 Chasmataspis laurencii.png
| image2_caption = Life reconstruction of C. laurencii
| display_parents = 3
| parent_authority = Caster & Brooks, 1956
| taxon = Chasmataspis
| authority = Caster & Brooks, 1956
| type_species = †Chasmataspis laurencii
| type_species_authority = Caster & Brooks, 1999
}}
Chasmataspis is a genus of chasmataspidid, a group of extinct aquatic chelicerate arthropods.{{sfn|Dunlop|Penney|Jekel|2020|p=16}}{{sfn|Caster|Brooks|1956}} It was found in the Early Ordovician deposits of Tennessee, United States.
Morphology
Just like other chasmataspidids, the body of Chasmataspis compose of a prosoma and a 13-segmented opisthosoma, with the latter subdivided into a 4-segmented preabdomen and a 9-segmented postabdomen.{{Cite journal|last1=Dunlop|first1=Jason A.|last2=Anderson|first2=Lyall I.|last3=Braddy|first3=Simon J.|date=2003|title=A redescription of Chasmataspis laurencii Caster & Brooks, 1956 (Chelicerata: Chasmataspidida) from the Middle Ordovician of Tennessee, USA, with remarks on chasmataspid phylogeny|url=http://www.museunacional.ufrj.br/mndi/Aracnologia/Chasmataspidida/Dunlop%20et%20al%202007%20Chasmataspis.pdf|journal=Earth and Environmental Science Transactions of the Royal Society of Edinburgh|language=en|volume=94|issue=3|pages=207–225|doi=10.1017/S0263593300000626|issn=1473-7116}} Dorsal to the carapace were pairs of ridges, lateral eyes and median ocelli. Chasmataspis characterized by a semicircular carapace (prosomal dorsal shield) with pointed genal spines and preabdomen with fused body segments. Rows of tubercles and spines run through the axial and lateral regions of opisthosoma. The body terminated with a spine-like telson.
There is no body fossils of Chasmataspis with unambiguous appendages being discovered. The only evidence were 2 specimens of disarticulated, claw-bearing appendages discovered from the same stratum which may represent the prosomal appendage (possibly appendage VI{{Cite journal|last1=Lamsdell|first1=James C.|last2=Gunderson|first2=Gerald O.|last3=Meyer|first3=Ronald C.|date=2019-01-08|title=A common arthropod from the Late Ordovician Big Hill Lagerstätte (Michigan) reveals an unexpected ecological diversity within Chasmataspidida|journal=BMC Evolutionary Biology|volume=19|issue=1|page=8|doi=10.1186/s12862-018-1329-4|issn=1471-2148|pmc=6325806|pmid=30621579 |doi-access=free }}) of Chasmastaspis.
References
{{reflist|2}}
=Cited bibliography=
- {{cite journal|url=https://www.biodiversitylibrary.org/item/40434#page/189|title=New fossils from the Canadian–Chazan (Ordovician) hiatus in Tennessee|first1=Kenneth E.|last1=Caster|author-link=Kenneth Edward Caster|first2=H. K.|last2=Brooks|journal=Bulletins of American Paleontology|volume=36|issue=157|year=1956|pages=157–199}}
- {{cite book|chapter-url=http://www.wsc.nmbe.ch/resources/fossils/Fossils20.5.pdf|title=World Spider Catalog|last1=Dunlop|first1=Jason A.|last2=Penney|first2=D.|last3=Jekel|first3=D.|publisher=Natural History Museum Bern|year=2020|chapter=A summary list of fossil spiders and their relatives}}
{{taxonbar|from=Q19832770}}
Category:Fossil taxa described in 1956
{{chelicerata-stub}}