Angulomastacator
From Latin 'angulus' meaning 'bend' or 'angle' and 'masticator' meaning 'chewer'; meaning 'bend chewer', referring to the bent shape of the jaw and the Big Bend area of Texas
Late Cretaceous stages
Angulomastacator is a genus of duck-billed dinosaur from the Campanian-aged (Late Cretaceous) Aguja Formation of Big Bend National Park, Texas.
Diagnosis
- Abrupt ~45° ventral deflection of anterior maxilla and occlusal plane, giving bone a 'boomerang' shape in lateral view
- Occlusal surfaces of mesial teeth positioned well ventral to distal teeth when in articulation
- Deflection steeper than any other known hadrosaurid (next closest ~25° in Brachylophosaurus and Lambeosaurus)
Species
Angulomastacator daviesi Wagner & Lehman, 2009
Type species
Named for Kyle L. Davies, who in 1983 was the first to postulate the presence of a lambeosaurine in the Aguja Formation of Texas.
- Holotype
- TMM 43681-1 , Texas Memorial Museum, Austin, Texas, USA (used for collections now housed in the Vertebrate Paleontology Collections at the Jackson School Museum of Earth History, Austin, Texas, USA), now called the Texas Science and Natural History Museum
- Material
- Incomplete left maxilla
- Horizon
- middle Alto Shale Member, Aguja Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
- Locality
- Dawson Creek, Texas, United States
References
- Wagner, J. R.; Lehman, T. M. (2009). An enigmatic new lambeosaurine hadrosaur (Reptilia: Dinosauria) from the Upper Shale member of the Campanian Aguja Formation of Trans-Pecos Texas. Journal of Vertebrate Paleontology 29(2): 605-611. Informa UK Limited. doi:10.1671/039.029.0208 wagner2009a
-
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.
Source of the body length estimate, and the appearance features.
jones2026a