''Aquilarhinus'' (meaning "

eagle Eagle is the common name for the golden eagle, bald eagle, and other birds of prey in the family of the Accipitridae. Eagles belong to several groups of Genus, genera, some of which are closely related. True eagles comprise the genus ''Aquila ( ...

snout" after the unusual beak morphology) is a genus of

hadrosaurid Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod fami ...

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

from the

Aguja Formation The Aguja Formation is a geological formation in North America, exposed in Texas, United States and Chihuahua and Coahuila in Mexico, whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered ...

from

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

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 2019.

Discovery

The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

fossil (TMM 42452-1) of Aquilarhinus was discovered in the Lower Shale of the

Big Bend National Park Big Bend National Park is a List of national parks of the United States, national park of the United States located in West Texas, bordering Mexico. The park has national significance as the largest protected area of Chihuahuan Desert topograph ...

. Most parts of the specimen were collected in 1983, but additional elements were collected during continued excavations in 1999. The specimen was first described in 2001 as a new species of ''

Kritosaurus ''Kritosaurus'' is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard" (referring to the arrangement of the cheek ...

'', because aside from its

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

it was morphologically very similar to ''Kritosaurus notabilis''. The differences in the rostrum were interpreted as being a functional adaptation for "shoveling out and scooping up vegetation." Despite the fossil's identification within the genus ''Kritosaurus'', its phylogenetic position remained unclear. In 2019, the species was reclassified into a new genus and given its binomial name ''Aquilarhinus palimentus''. ''Aquilarhinus'' comes from the Latin words 'aquila' meaning 'eagle' and 'rhinus' meaning 'nose', referring to the unique shape of the rostrum, and ''palimentus'' comes from the Latin words 'pala', meaning shovel, and 'mentus', meaning chin, referring the shape of the

predentary Ornithischia () is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Ancient ...

and its resemblance to a spade or shovel.

References

Notes

Sources

* * {{Portal bar, Dinosaurs, Texas Hadrosauridae Dinosaur genera Campanian dinosaurs Fossil taxa described in 2019 Dinosaurs of the United States

Discovery

See also

References

Notes

Sources