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.
![]() |
![]() |
![]() |