#ampelognathus

[totaldino]

Ampelognathus

Ampelognathus is a small basal ornithopod dinosaur. The dentary of Ampelognathus generally resembles those in other small ornithopods, but is slightly twisted along its length so that the teeth in the back of the jaw pointed somewhat inward. Ampelognathus measured about 80 cm in length, and 2 kg im body mass.

[mesozoicmarket]

A group of dinosaur teeth, possibly Protohadros byrdi from the Woodbine Formation in Dallas/Fort Worth Airport in Dallas County, Texas, United States. Another ornithopod, Ampelognathus coheni is also described from the Woodbine Group. It's always difficult, if not impossible to assign isolated ornithopod teeth to a specific taxa, especially incomplete or worn specimens.

[new-dinosaurs]

Ampelognathus coheni Tykoski et al., 2023 (new genus and species)

(Type jaw of Ampelognathus coheni [scale bars = 5 mm], from Tykoski et al., 2023)

Meaning of name: Ampelognathus = grapevine jaw [in Greek, referring to its discovery in the emergency spillway for Grapevine Lake]; coheni = for Murray Cohen [discoverer of the original fossil]

Age: Late Cretaceous (Cenomanian), around 96 million years ago

Where found: Lewisville Formation, Texas, U.S.A.

How much is known: The left half of a partial lower jaw.

Notes: Ampelognathus was an ornithopod, a diverse group of plant-eating dinosaurs that includes the duck-billed hadrosaurids. Although hadrosaurids included the largest known ornithischian ("bird-hipped") dinosaurs and probably spent most of their time on all fours, the earliest ornithopods were small, bipedal forms, and it was probably this ancestral body plan that was retained by Ampelognathus.

Ampelognathus is the first small ornithopod and one of the few ornithischians known from the Lewisville Formation. Its lower jaw was generally similar to that of other small ornithopods, but differs from theirs in several features, such as being slightly twisted along its length so that the teeth in the back of the jaw pointed somewhat inward.

Reference: Tykoski, R.S., D.L. Contreras, and C. Noto. 2023. The first small-bodied ornithopod dinosaur from the Lewisville Formation (middle Cenomanian) of Texas. Journal of Vertebrate Paleontology advance online publication. doi: 10.1080/02724634.2023.2257238