Mesochelydia

Mesochelydia is a clade within Pantestudines, more inclusive than Perichelydia, but less than Testudinata. The clade is known from the Early Jurassic to the Present, and contains all Jurassic representatives of Testudinata aside from Australochelys. The ancestral condition for Mesochelydia is thought to be aquatic, as opposed to terrestrial for Testudinata. They are distinguished from more basal testudinatans by the presence of the following characters: strap like pectoral girdle, supramarginals absent, reduced posterior entoplastral process, eleven pairs of peripherals, elongate processus interfenestralis, paired basioccipital tubercles, fully formed cavum tympani and antrum postoticum, single vomer, confluent external nares, lacrimals and supratemporals absent.

Mesochelydia

Uncredited · 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
TestudinataPBDB
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Diapsida

Time the record covers

At least 49 million years on record.

The record covers at least 192.9 Mya to 143.1 Mya. No occurrence read is dated outside 201.4 Mya to 121.4 Mya.

Late Triassic — about 0 of 20 occurrencesEarly Jurassic — about 16 of 20 occurrencesEarly JurassicMiddle Jurassic — about 3 of 20 occurrencesMiddle JurassicLate Jurassic — about 0 of 20 occurrencesEarly Cretaceous — about 1 of 20 occurrencesEarly Cretaceous203–200 Mya — about 0.3 occurrences200–197 Mya — about 2 occurrences197–195 Mya — about 2 occurrences195–192 Mya — about 2 occurrences192–189 Mya — about 2 occurrences189–186 Mya — about 2 occurrences186–184 Mya — about 2 occurrences184–181 Mya — about 2 occurrences181–178 Mya — about 1 occurrence178–175 Mya — about 1.0 occurrences175–172 Mya — about 0.7 occurrences172–170 Mya — about 0.4 occurrences170–167 Mya — about 0.9 occurrences167–164 Mya — about 1 occurrence145–142 Mya — about 0.1 occurrences142–139 Mya — about 0.1 occurrences139–136 Mya — about 0.1 occurrences136–134 Mya — about 0.1 occurrences134–131 Mya — about 0.1 occurrences131–128 Mya — about 0.1 occurrences128–125 Mya — about 0.1 occurrences125–123 Mya — about 0.1 occurrences123–120 Mya — about 0.1 occurrences192.9 Mya143.1 Mya203 Mya120 Mya

20 occurrences of Mesochelydia on record, most of them in the Early Jurassic. 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

20 occurrences

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

6 formations

Kayenta — 35.75°N, 111.08°WKayenta — 37.00°N, 110.70°WKayenta — 35.74°N, 111.07°WCañadón Asfalto — 43.41°S, 69.23°WCañadón Asfalto — 43.45°S, 69.18°WKota — 18.90°N, 79.97°EKota — 19.25°N, 79.53°EMoskovoretskaya — 55.20°N, 38.78°EKilmaluag — 57.17°N, 6.11°WBatylykh — 62.73°N, 117.61°E

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The named rock units Mesochelydia has been recovered from, largest first. Drawn where the rock is now, not where it formed.

Mesochelydia and its relatives

Early Jurassic

Where Mesochelydia and its relatives were recorded in the Early Jurassic.

Found in the same rock

127 taxa

The Paleobiology Database records 18 sites for Mesochelydia, 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

10 references

Each of the 20 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 Mesochelydia

Credit
nobody named on the record
Licence
not stated by the source
Commercial use
cannot be read from the licence given — check the record

No 3D scan of Mesochelydia 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 itTestudinata through timeFormations of the Early JurassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Joyce 2017