Mesodermochelys
Mesodermochelys is an extinct genus of sea turtle known from the Campanian to the Maastrichtian of what today is Japan and from the Maastrichtian of Chile. One species is known, the type species M. undulatus; it was given its binomial name by Ren Hirayama and Tsutomu Chitoku in 1996. Studies of its skull indicate that it was a primitive member of the Dermochelyidae that was closely related to the Protostegidae. It has been described as the best representative of Mesozoic dermochelyids.

ぽん吉 · CC BY-SA 4.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.
On record
Recorded, not inferred- Sits inside
- DermochelyidaePBDB
- Diet
- durophage, piscivorePBDB, for Dermochelyidae
- Life habit
- aquaticPBDB, for Dermochelyidae
- Motility
- actively mobilePBDB, for Osteichthyes
- Environment
- marinePBDB, for Dermochelyidae
Time the record covers
At most 18 million years on record.
Every occurrence read is dated to somewhere between 83.6 Mya and 66 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.
13 occurrences of Mesodermochelys on record, most of them in the Late Cretaceous. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.
When
13 occurrences- Late Cretaceous100%
These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.
Found in
5 formations
- Hakobuchi Formation · Yezo Group8
- Osoushinai Formation · Upper Yezo Group2
- Estratos de Quebrada Municipalidad Formation1
- Kita-ama Formation · Izumi Group1
- Toriyashiro Formation · Sotoizumi Group1
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The named rock units Mesodermochelys has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Mesodermochelys and its relatives
Late CretaceousWhere Mesodermochelys and its relatives were recorded in the Late Cretaceous.
Found in the same rock
33 taxa- Biropristis landbecki1 site
- Carcharias gracilis1 site
- Centrophoroides appendiculatus1 site
- Chelonioidea1 site
- Cretorectolobus1 site
- Echinorhinus maremagnum1 site
- Edaphodon kawai1 site
- Elasmosauridae1 site
- Eutrephoceras1 site
- Gastropoda1 site
- Gigantocapulus problematicus1 site
- Gyrodes1 site
- Hesperornithiformes1 site
- Hikidea1 site
- Inoceramus shikotanensis1 site
- Ischyrhiza chilensis1 site
- Kamuysaurus japonicus1 site
- Mosasauridae1 site
- Myledaphus araucanus1 site
- Nostoceras hetonaiense1 site
- Odontaspis winkleri1 site
- Orectolobidae1 site
- Paraorthacodus1 site
- Platanus1 site
The Paleobiology Database records 13 sites for Mesodermochelys, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.
This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.
Entered from
6 references- Family Dermochelyidae (superfamily Chelonioidea) from the Upper Cretaceous of north Japan8
- Review of two marine vertebrate assemblages from the Arauco Basin (central Chile) reveals diversity changes throughout the Maastrichtian1
- A chelonioid marine turtle from the Upper Cretaceous of Wakayama Prefecture, south-western Japan1
- A new basal hadrosaurid (Dinosauria: Ornithischia) from the latest Cretaceous Kita-ama Formation in Japan implies the origin of hadrosaurids1
- Discovery of chemosynthesis-based association on the Cretaceous basal leatherback sea turtle from Japan1
- Mesodermochelys (Testudines; Chelonioidea; Dermochelyidae) from the Late Cretaceous of Nakagawa-cho, Hokkaido, North Japan1
Each of the 13 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content1
Picture of Mesodermochelys
- Source
- Wikipedia/Commons
- Credit
- ぽん吉
- Licence
- CC BY-SA 4.0
- Commercial use
- the licence allows it
No 3D scan of Mesodermochelys was found in Sketchfab.
Smithsonian Open Access and MorphoSource were not reached for this taxon, so this list is what the others held rather than everything there is.
The description on this site
- Licence
- CC BY-SA 4.0
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itDermochelyidae through timeFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Hirayama and Chitoku 1996