Mesosaurus

Mesosaurus is an extinct genus of aquatic reptile from the late Early Permian of southern Africa and South America. It is the only member of the family Mesosauridae and order Mesosauria. Two other genera of mesosaurs, Brazilosaurus and Stereosternum, were formerly recognised, but are now considered synonyms of Mesosaurus. Mesosaurus contains a single valid species, M. tenuidens. Mesosaurus represents one of the earliest lineages of aquatically adapted reptiles. It had many adaptations to a fully aquatic lifestyle. Mesosaurus lived around the shorelines of the Irati–Whitehill sea, an epicontinental sea that covered parts of southern Pangaea during the late Early Permian, likely feeding on small prey such as pygocephalomorph crustaceans. Mesosaurs have often been considered parareptiles, though the validity of "Parareptilia" has recently been brought into question. Recent studies regardless place mesosaurs as basal, non-diapsid reptiles.

Mesosaurus

Kevmin · CC BY-SA 3.0 · 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
MesosauridaePBDB
Diet
piscivorePBDB, for Mesosauridae
Life habit
amphibiousPBDB, for Mesosauridae
Motility
actively mobilePBDB, for Mesosauridae
Environment
coastal,marine,brackishPBDB, for Mesosauridae

Time the record covers

At most 6.8 million years on record.

Every occurrence read is dated to somewhere between 290.1 Mya and 283.3 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Permian — about 30 of 30 occurrencesPermian290–290 Mya — about 0.1 occurrences290–290 Mya — about 1 occurrence290–290 Mya — about 1 occurrence290–289 Mya — about 1 occurrence289–289 Mya — about 1 occurrence289–289 Mya — about 1 occurrence289–289 Mya — about 1 occurrence289–288 Mya — about 1 occurrence288–288 Mya — about 1 occurrence288–288 Mya — about 1 occurrence288–287 Mya — about 1 occurrence287–287 Mya — about 1 occurrence287–287 Mya — about 1 occurrence287–287 Mya — about 1 occurrence287–286 Mya — about 1 occurrence286–286 Mya — about 1 occurrence286–286 Mya — about 1 occurrence286–286 Mya — about 1 occurrence286–285 Mya — about 1 occurrence285–285 Mya — about 1 occurrence285–285 Mya — about 1 occurrence285–285 Mya — about 1 occurrence285–284 Mya — about 1 occurrence284–284 Mya — about 1 occurrence284–284 Mya — about 1 occurrence284–284 Mya — about 1 occurrence284–283 Mya — about 1 occurrence283–283 Mya — about 0.1 occurrences290.6 Mya282.8 Mya

30 occurrences of Mesosaurus on record, most of them in the Permian. 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

30 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

7 formations

  • Irati Formation · Passa Dois GroupGoiás, Paraná, Rio Grande do Sul · BR · 290.1–283.3 Mya14
  • Huab Formation · "Ecca" GroupErongo · NA · 290.1–283.3 Mya4
  • Whitehill Formation · Ecca GroupNorthern Cape · ZA · 290.1–283.3 Mya4
  • Melo FormationCerro Largo · UY · 290.1–283.3 Mya4
  • Whitehill Formation · Ecca GroupKaras · NA · 290.1–283.3 Mya2
  • ? Whitehill Formation · Ecca GroupNorthern Cape · ZA · 290.1–283.3 Mya1
Irati — 17.48°S, 52.05°WIrati — 25.84°S, 50.42°WIrati — 30.34°S, 54.33°WIrati — 23.59°S, 48.05°WIrati — 25.48°S, 50.65°WIrati — 22.98°S, 47.86°WIrati — 22.52°S, 47.58°WIrati — 25.62°S, 50.69°WIrati — 25.10°S, 50.17°WHuab — 21.20°S, 14.05°EWhitehill — 31.47°S, 19.77°EWhitehill — 31.38°S, 19.11°EWhitehill — 28.74°S, 24.77°EMelo — 31.93°S, 54.02°WWhitehill — 26.32°S, 18.25°E? Whitehill — 29.65°S, 24.20°E? Whitehill — 25.84°S, 18.01°E

Loading coastlines…

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

Mesosaurus and its relatives

Permian

Where Mesosaurus and its relatives were recorded in the Permian.

Found in the same rock

1 taxon

The Paleobiology Database records 11 sites for Mesosaurus, and this reads all of them. The number is how many of those sites it was catalogued from too.

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

15 references

Each of the 30 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. 3 further references are not listed. 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 content2

Picture of Mesosaurus

Credit
Kevmin
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

3D model

Source
Sketchfab
Licence
CC Attribution
Commercial use
cannot be read from the licence given — check the record

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 itMesosauridae through timeFormations of the PermianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Gervais 1865