Axestemys

Name: Axestemys.
Phonetic: Ax-e-stem-iss.
Named By: Hay‭ ‬-‭ ‬1899.
Synonyms: Axestus,‭ ‬Conchochelys,‭ ‬Eurycephalochelys,‭ ‬Paleotrionyx.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Testudines,‭ ‬Cryptodira,‭ ‬Trionychidae,‭ ‬Trionychinae.
Species: A.‭ ‬byssina‭ (‬type‭)‬,‭ ‬A.‭ ‬cerevisia,‭ ‬A.‭ ‬erquelinnensis,‭ ‬A. infernalis, A.‭ ‬montinsana,‭ ‬A.‭ ‬quinni,‭ ‬A.‭ ‬splendida,‭ ‬A.‭ ‬vittata.
Diet: Carnivore/Omnivore‭?
Size: Size varies considerably between‭ ‬species.‭ ‬One of the largest individuals belongs to A.‭ ‬byssina and has a body length of at least two meters.
Known locations: Belgium.‭ ‬Canada.‭ ‬France.‭ ‬UK.‭ ‬USA.
Time period: Late Cretaceous to Eocene,‭ ‬possibly later.
Fossil representation: Numerous individuals of varying levels of completeness.

       Axestemys is a genus of soft shelled turtle that lived from the Late Cretaceous to at‭ ‬least the Eocene,‭ ‬and is known from both North America and Europe.‭ ‬Instead of a hard shell,‭ ‬Axestemys would have had a tough leathery skin surrounding its body.‭ ‬Modern day soft shelled turtles can be omnivorous,‭ ‬meaning they eat both plants and animals,‭ ‬though many‭ ‬species are exclusive carnivores.‭ ‬Prey animals of soft shelled turtles include fish,‭ ‬molluscs,‭ ‬amphibians,‭ ‬crustaceous,‭ ‬virtually any small aquatic organism that they can catch.‭ ‬It is thus inferred that Axestemys had a similar predatory behaviour.




Further reading
-‭ ‬Descriptions of some new Vertebrata from the Bridger Group of the Eocene.‭ ‬Proceedings of the American Philosophical Society‭ ‬12:460-465.‭ ‬-‭ ‬E.‭ ‬D.‭ ‬Cope‭ ‬-‭ ‬1871.
-‭ ‬A new turtle from the Paleocene of Colorado.‭ ‬-‭ ‬Fieldiana Geology‭ ‬10:1-4.‭ ‬-‭ ‬K.‭ ‬P.‭ ‬Schmidt‭ ‬-‭ ‬1945.
-‭ ‬Giant fossil soft-shelled turtles of North America.‭ ‬-‭ ‬Palaeontologia Electronica.‭ ‬-‭ ‬Natasha S.‭ ‬Vitek‭ ‬-‭ ‬2012.
- A new species of trionychid turtle, Axestemys infernalis sp. nov., from the Late Cretaceous (Maastrichtian) Hell Creek and Lance formations of the Northern Great Plains, USA. - Palaeontologia Electronica. 33 (3): 1–28. - Walter G. Joyce, Donald B. Brinkman & Tyler R. Lyson - 2019.

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