Paraorthacodus Explained

Paraorthacodus is an extinct genus of shark. It a member of the family Paraorthacodontidae (though it was formerly regarded as a member of the family Palaeospinacidae[1]), which is either placed in Hexanchiformes[2] or in Synechodontiformes.[3] It is known from over a dozen named species[4] spanning from the Early Jurassic to the Paleocene, or possibly Eocene. Almost all members of the genus are exclusively known from isolated teeth, with the exception of P. jurensis from the Late Jurassic-Early Cretaceous of Europe, which is known from full body fossils from the Late Jurassic of Germany,[5] which suggest that juveniles had a robust body with a round head, while adults had large body sizes with a fusiform profile. There was only a single dorsal fin towards the back of the body without a fin spine. The dentition had teeth with a single large central cusp along with shorter lateral cusplets, which where designed for clutching. The teeth are distinguished from those of Synechodus by the lateral cusplets decreasing in size linearly away from the central cusp rather than exponentially as in Synechodus.

Taxonomy

After

Notes and References

  1. Klug . Stefanie . Kriwet . JüRgen . BöTtcher . Ronald . Schweigert . GüNter . Dietl . Gerd . September 2009 . Skeletal anatomy of the extinct shark Paraorthacodus jurensis (Chondrichthyes; Palaeospinacidae), with comments on synechodontiform and palaeospinacid monophyly . Zoological Journal of the Linnean Society . en . 157 . 1 . 107–134 . 10.1111/j.1096-3642.2009.00534.x.
  2. Cione . Alberto L. . Santillana . Sergio . Gouiric-Cavalli . Soledad . Acosta Hospitaleche . Carolina . Gelfo . Javier N. . López . Guillermo M. . Reguero . Marcelo . May 2018 . Before and after the K/Pg extinction in West Antarctica: New marine fish records from Marambio (Seymour) Island . Cretaceous Research . en . 85 . 250–265 . 10.1016/j.cretres.2018.01.004. 2018CrRes..85..250C . 133767014 . 11336/99687 . free .
  3. Villalobos-Segura . Eduardo . Stumpf . Sebastian . Türtscher . Julia . Jambura . Patrick L. . Begat . Arnaud . López-Romero . Faviel A. . Fischer . Jan . Kriwet . Jürgen . March 2023 . A Synoptic Review of the Cartilaginous Fishes (Chondrichthyes: Holocephali, Elasmobranchii) from the Upper Jurassic Konservat-Lagerstätten of Southern Germany: Taxonomy, Diversity, and Faunal Relationships . Diversity . en . 15 . 3 . 386 . 10.3390/d15030386 . 1424-2818 . free. 36950327 . 7614348 .
  4. Cappetta . Henri . Morrison . Kurt . Adnet . Sylvain . 2021-08-03 . A shark fauna from the Campanian of Hornby Island, British Columbia, Canada: an insight into the diversity of Cretaceous deep-water assemblages . Historical Biology . en . 33 . 8 . 1121–1182 . 10.1080/08912963.2019.1681421 . 2021HBio...33.1121C . 212878837 . 0891-2963.
  5. Stumpf . Sebastian . Kriwet . Jürgen . December 2019 . A new Pliensbachian elasmobranch (Vertebrata, Chondrichthyes) assemblage from Europe, and its contribution to the understanding of late Early Jurassic elasmobranch diversity and distributional patterns . PalZ . en . 93 . 4 . 637–658 . 10.1007/s12542-019-00451-4 . 2019PalZ...93..637S . 0031-0220. free .
  6. Rodríguez . Diego . Ward . David John . Quezada . Jorge Andrés . 2023-06-07 . Paleontology and stratigraphic implications of a late Paleocene elasmobranch assemblage in Talcahuano, southcentral Chile . Andean Geology . 50 . 2 . 217 . 10.5027/andgeoV50n2-3494 . 259771898 . 0718-7106.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Paraorthacodus".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.