Stereognathus
Stereognathus is an extinct genus of tritylodontid cynodonts from the Middle Jurassic of the United Kingdom. There is a single named species: S. ooliticus, named after the Great Oolite deposits of England. A second species, S. hebridicus, was named after the Hebrides in Scotland, where it was found; it was synonymized with S. ooliticus in 2017.

Sir Richard Owen (Life time: 1804-1892) · Public Domain · 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
- TritylodontidaePBDB
- Motility
- actively mobilePBDB, for Osteichthyes
- Environment
- terrestrialPBDB, for Amniota
Time the record covers
At least 43 million years on record.
The record covers at least 165.3 Mya to 121.4 Mya. No occurrence read is dated outside 168.2 Mya to 113.2 Mya.
15 occurrences of Stereognathus on record, most of them in the Middle 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
15 occurrencesThese 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
9 formations
- Forest Marble Formation · Great Oolite Group5
- Ilek Formation3
- Chipping Norton Limestone Formation · Great Oolite Group1
- Itat Formation1
- Hampen Marly Formation1
- Taynton Limestone Formation · Great Oolite Group1
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The named rock units Stereognathus has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Stereognathus and its relatives
Middle JurassicWhere Stereognathus and its relatives were recorded in the Middle Jurassic.
Found in the same rock
260 taxa- Caudata11 sites
- Mammalia10 sites
- Choristodera9 sites
- Testudines9 sites
- Tritylodontidae9 sites
- Crocodylia7 sites
- Cteniogenys7 sites
- Goniopholididae7 sites
- Scincomorpha7 sites
- Coelurosauria6 sites
- Pterosauria6 sites
- Theropoda6 sites
- Lepidosauromorpha5 sites
- Marmorerpeton5 sites
- Ornithischia5 sites
- Stegosauria5 sites
- Therapsida5 sites
- Albanerpetontidae4 sites
- Ankylosauria4 sites
- Anura4 sites
- Eupantotheria4 sites
- Fabrosauridae4 sites
- Sphenodontia4 sites
- Squamata4 sites
The Paleobiology Database records 15 sites for Stereognathus, 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
11 references- A reassessment of the postcanine dentition and systematics of the tritylodontid Stereognathus (Cynodontia, Tritylodontidae, Mammaliamorpha), from the Middle Jurassic of the United Kingdom3
- Middle Jurassic microvertebrate assemblages from the British Isles3
- Palaeontology, stratigraphy and sedimentology of Woodeaton Quarry (Oxfordshire) and a new microvertebrate site from the White Limestone Formation (Bathonian, Jurassic)1
- A tritylodontid synapsid from the Middle Jurassic of Siberia and the taxonomy of derived tritylodontids1
- Two new mammal localities within the Lower Cretaceous Ilek Formation of West Siberia, Russia1
- Taphonomy of the Upper Mesozoic Tetrapod Teete Locality (Yakutia)1
- Early Cretaceous mammals from Bol'Shoi Kemchug 3 locality in West Siberia, Russia1
- Predvaritel'nye rezul'taty izucheniy mestonakhozhdenii Shestakovskogo kompleksa rannemelovykh pozvonochnykh [Preliminary results of the investigation of the Shestakovo localities of Early Cretaceous vertebrates]1
- Small reptiles and amphibians from the Forest Marble (Middle Jurassic) of Dorset1
- The first Jurassic mammal from Scotland1
- Monograph of the fossil Mammalia of the Mesozoic formations1
Each of the 15 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 Stereognathus
- Source
- Wikipedia/Commons
- Credit
- Sir Richard Owen (Life time: 1804-1892)
- Licence
- Public Domain
- Commercial use
- the licence allows it
No 3D scan of Stereognathus was found in MorphoSource and Sketchfab.
Smithsonian Open Access was 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 itTritylodontidae through timeFormations of the Middle JurassicThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Charlesworth 1854