Pasternakevia

{{Short description|Extinct genus of chelicerate}}

{{Automatic taxobox

| name = Pasternakevia

| fossil_range = {{fossil range|Ludlow}}

| image = Pasternakevia podolica.jpg

| image_caption = Fossils and illustrations of P. podolica

| display_parents = 2

| taxon = Pasternakevia

| authority = Selden & Drygant, 1987

| type_species = †Pasternakevia podolica

| type_species_authority = Selden & Drygant, 1987

| subdivision_ranks =

| subdivision =

| synonyms =

}}

File:20200927 Pasternakevia podolica.png

Pasternakevia is a genus of synziphosurine,{{Cite journal|last1=Krzemiński|first1=Wiesław|last2=Krzemińska|first2=Ewa|last3=Wojciechowski|first3=Dariusz|date=2010|title=Silurian Synziphosurine Horseshoe Crab Pasternakevia Revisited|url=https://www.app.pan.pl/article/item/app20080074.html|journal=Acta Palaeontologica Polonica|language=en|volume=55|issue=1|pages=133–139|doi=10.4202/app.2008.0074|issn=0567-7920|doi-access=free}} a paraphyletic group of fossil chelicerate arthropods.{{Cite journal|last1=Bicknell|first1=Russell D. C.|last2=Pates|first2=Stephen|date=2020|title=Pictorial Atlas of Fossil and Extant Horseshoe Crabs, With Focus on Xiphosurida|journal=Frontiers in Earth Science|language=en|volume=8|page=98|doi=10.3389/feart.2020.00098|bibcode=2020FrEaS...8...98B|issn=2296-6463|doi-access=free}} Pasternakevia was regarded as part of the clade Planaterga.{{Cite journal|last1=Selden|first1=Paul A.|last2=Lamsdell|first2=James C.|last3=Qi|first3=Liu|title=An unusual euchelicerate linking horseshoe crabs and eurypterids, from the Lower Devonian (Lochkovian) of Yunnan, China|url=https://www.academia.edu/14633144|journal=Zoologica Scripta|year=2015 |language=en|volume=44|issue=6|pages=645–652|doi=10.1111/zsc.12124 |s2cid=55264483 |issn=0300-3256|doi-access=free}}{{Cite journal|last1=Lamsdell|first1=James C.|last2=Briggs|first2=Derek E. G.|last3=Liu|first3=Huaibao P.|last4=Witzke|first4=Brian J.|last5=McKay|first5=Robert M.|date=2015|title=A new Ordovician arthropod from the Winneshiek Lagerstätte of Iowa (USA) reveals the ground plan of eurypterids and chasmataspidids|url=https://www.researchgate.net/publication/282127302|journal=The Science of Nature|language=en|volume=102|issue=9–10|pages=63|doi=10.1007/s00114-015-1312-5|pmid=26391849|bibcode=2015SciNa.102...63L|s2cid=8153035|issn=0028-1042}}{{Cite journal|last1=Bicknell|first1=Russell D. C.|last2=Lustri|first2=Lorenzo|last3=Brougham|first3=Tom|date=2019-12-01|title=Revision of "Bellinurus" carteri (Chelicerata: Xiphosura) from the Late Devonian of Pennsylvania, USA|journal=Comptes Rendus Palevol|language=en|volume=18|issue=8|pages=967–976|doi=10.1016/j.crpv.2019.08.002|issn=1631-0683|doi-access=free}} Fossils of the single and type species, P. podolica, have been discovered in deposits of the Silurian period in Podolia, Ukraine.{{cite book|chapter-url=http://www.wsc.nmbe.ch/resources/fossils/Fossils20.5.pdf|title=World Spider Catalog|last1=Dunlop|first1=J. 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|pages=1–296}}{{cite journal|last=Lamsdell|first=James C.|year=2013|title=Revised systematics of Palaeozoic 'horseshoe crabs' and the myth of monophyletic Xiphosura|journal=Zoological Journal of the Linnean Society|volume=167|issue=1|pages=1–27|doi=10.1111/j.1096-3642.2012.00874.x|issn=0024-4082|doi-access=free}}

The prosoma of Pasternakevia covered by a smooth, semicircular carapace with rounded genal cornua (posterolateral corner of carapace). Within the 10-segmented opisthosoma, tergite of the first segment is reduced and usually hidden under the preceding carapace, while the second one is significantly arched and well-developed. All but the first tergite possess well-developed pleurae (lateral extension). A complete telson is yet to be discovered.