Archaeodontosaurus
"ancient-toothed lizard"
- Lived
- 168 to 165 million years ago, Middle Jurassic
- Diet
- Herbivore
- Group
- Sauropods
- Found in
- Madagascar
- Named by
- Buffetaut 2005
Where its fossils were found
The evidence
Today
165 million years ago
Habitat
Its fossils come from deposits laid down on land and in brackish water in what is now Madagascar. Lapparentosaurus is another sauropod known from the island's Middle Jurassic rocks.
Field notes
About Archaeodontosaurus
What it was like
Archaeodontosaurus was a long-necked plant eater known only from a piece of lower jaw with teeth. Its teeth look like those of earlier, smaller relatives of sauropods, more than those of other sauropods of its time.
Its world
It lived about 168 to 165 million years ago, in the Middle Jurassic, in what is now Madagascar.
How it was found
Buffetaut named Archaeodontosaurus in 2005, from a single find.
Field gallery
More views of Archaeodontosaurus
Scenes reconstructed from the available fossil evidence.
The evidence
The science behind Archaeodontosaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- The only known fossil is part of a lower jaw, with teeth still forming inside their sockets.
- The jaw deepens and strengthens toward the front. Its leaf-shaped teeth have large, slanting serrations, finely wrinkled enamel and rounded inner faces.
Borrowed from relatives
- Only the jaw is known, so the rest of the head and the body can only be restored from other early sauropods.
Still unknown
- Its body size, its proportions and the shape of the rest of its skull.
- Whether it was a sauropod at all. Studies of the jaw treat it as an early sauropod, but one study noted that an older plant-eating reptile from Madagascar, which was not a dinosaur, had a similarly deep jaw front and leaf-shaped teeth.
- Its skin covering and color.
Discovery timeline
- 2005Named itBuffetaut
- 2007Close relativeUPCHURCH et al.
- 2010Same rocksMANNION
- 2010Family treeFLYNN et al.
- 2019Same rocksBindellini & Dal Sasso
- 2022Family treeRincón et al.
Key papers
The research behind what we know of Archaeodontosaurus
Named it
Described a deep sauropod jaw with leaf-shaped, serrated teeth resembling those of earlier long-necked plant eaters.
A new sauropod dinosaur with prosauropod-like teeth from the Middle Jurassic of Madagascar. Bulletin de la Société Géologique de France 176: 467-473
Read the paper : A new sauropod dinosaur with prosauropod-like teeth from the Middle Jurassic of Madagascar (opens in a new tab)Close relative
Compared early sauropod jaws, including Archaeodontosaurus, to trace changes in tooth shape and feeding anatomy.
A re-evaluation of Chinshakiangosaurus chunghoensis Ye vide Dong 1992 (Dinosauria, Sauropodomorpha): implications for cranial evolution in basal sauropod dinosaurs. Geological Magazine 144: 247-262
Read the paper : A re-evaluation of Chinshakiangosaurus chunghoensis Ye vide Dong 1992 (Dinosauria, Sauropodomorpha): implications for cranial evolution in basal sauropod dinosaurs (opens in a new tab)Same rocks
Reviewed the Middle Jurassic sauropods of Madagascar, treating Archaeodontosaurus as known from its jaw alone and keeping other bones from the island separate.
A revision of the sauropod dinosaur genus ‘Bothriospondylus’ with a redescription of the type material of the Middle Jurassic form ‘B. madagascariensis’. Palaeontology 53: 277-296
Read the paper : A revision of the sauropod dinosaur genus ‘Bothriospondylus’ with a redescription of the type material of the Middle Jurassic form ‘B. madagascariensis’ (opens in a new tab)Family tree
Described the skull of a reptile that was not a dinosaur and noted that its jaw and teeth resemble those of Archaeodontosaurus.
A new species of Azendohsaurus (Diapsida: Archosauromorpha) from the Triassic Isalo Group of southwestern Madagascar: cranium and mandible. Palaeontology 53: 669-688
Read the paper : A new species of Azendohsaurus (Diapsida: Archosauromorpha) from the Triassic Isalo Group of southwestern Madagascar: cranium and mandible (opens in a new tab)Same rocks
Described loose sauropod teeth from Madagascar and compared them with the Archaeodontosaurus jaw, tentatively linking some of them to it.
Sauropod teeth from the Middle Jurassic of Madagascar, and the oldest record of Titanosauriformes. Papers in Palaeontology 7: 137-161
Read the paper : Sauropod teeth from the Middle Jurassic of Madagascar, and the oldest record of Titanosauriformes (opens in a new tab)Family tree
Described Perijasaurus and analyzed early sauropod relationships, showing that these plant eaters spread widely before the continents separated further.
A sauropod from the Lower Jurassic La Quinta Formation (Dept. Cesar, Colombia) and the initial diversification of eusauropods at low latitudes. Journal of Vertebrate Paleontology 42
Read the paper : A sauropod from the Lower Jurassic La Quinta Formation (Dept. Cesar, Colombia) and the initial diversification of eusauropods at low latitudes (opens in a new tab)
Close relatives
Other members of Sauropoda
Sources: Wikidata