Aquilarhinus
From Latin 'aquila' meaning 'eagle' and Greek 'rhinos' meaning 'snout' or 'nose'; meaning 'eagle snout', after the unusual beak morphology
Aquilarhinus is a genus of hadrosaurid ornithopod dinosaur from the Aguja Formation from Texas in the United States. The type and only species is Aquilarhinus palimentus. Due to its unusual dentary, it has been inferred to have had shovel-like beak morphology, different from the beaks of other hadrosaurs. It was originally classified as a Kritosaurus sp. before being reclassified as a new genus in 2020.
Diagnosis
- Nasals transversely broad across skull table, forming an extremely broad and subcircular lateral profile of the external bony naris.
- Premaxillary shelf of maxilla at anterior apex flat and as broad as the proximal segment of the palatal process.
- Palatine extending nearly horizontally to contact the maxilla, rather than subvertically as in other hadrosaurids.
- Symphysial process of dentary dorsally reflected, causing paired dentaries to meet in a W-shaped anterior profile rather than the typical U-shape.
- Maxilla with jugal process and ectopterygoid ridge continuous with ventral margin of jugal facet (unique combination among hadrosaurids).
Species
Aquilarhinus palimentus Prieto-Márquez et al., 2020
Type species
From Latin, combining pala, meaning 'shovel', and mentus, meaning 'chin', referring to the shape of the predentary and its resemblance to a spade or shovel.
- Holotype
- TMM 42452-1 , 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
- Sphenoid fragment, both nasals, right maxilla, right jugal, right quadratojugal, partial palatines, partial right dentary, partial first ceratobranchial, atlas neural arch fragment, cervical centra fragments, cervical ribs, partial sacral rib, left carpal, nearly complete left manus, postacetabular process of right ilium, right ischium fragment, partial astragali, pedal phalanx III-1, and four pedal unguals.
- Horizon
- Abajo Shale Member, Aguja Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
- Locality
- western flank of Rattlesnake Mountain, Texas, United States
References
- Prieto-Márquez, A.; Wagner, J. R.; Lehman, T. (2020). An unusual 'shovel-billed' dinosaur with trophic specializations from the early Campanian of Trans-Pecos Texas, and the ancestral hadrosaurian crest. Journal of Systematic Palaeontology 18(6): 461-498. Informa UK Limited. doi:10.1080/14772019.2019.1625078 prieto-márquez2020a
-
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.
Source of the body length, mass, and hip height estimates, and the appearance features.
jones2026a