A surprisingly complete skull of a duck-billed dinosaur was recently found in Big Bend National Park, Texas, leading to a new identification of a previously unknown, oddly shaped, dinosaur.
Research, detailed in a new paper in the Journal of Systematic Palaeontology, revealed that the fossils are of a previously unidentified genus and species; the newly named Aquilarhinus palimentus.
Aquilarhinus palimentus was named for its aquiline nose, and wide lower jaw, shaped like two trowels laid side by side.
Fossils for the dinosaur were already found in the 1980s. As Phys.org reports, Texas Tech University Professor Tom Lehman (then a Master's student) was carrying out research on rock layers at Rattle Snake Mountain when he discovered poorly preserved fossils.
Some of these bones were stuck together, making them impossible to study. Further research in the 1990s suggested the specimen might be a hadrosaurid Gryposaurus — due to its distinctive arched nasal crest.
New research has revealed that the dinosaur was more primitive than Gryposaurus and the two major groups of duck-billed dinosaurs.
A new piece of the hadrosaurids puzzle
"This new animal is one of the more primitive hadrosaurids known and can, therefore, help us to understand how and why the ornamentation on their heads evolved, as well as where the group initially evolved and migrated from," said lead author Dr. Albert Prieto-Márquez from the Institut Català de Paleontologia Miquel Crusafont, in a press release.
"Its existence adds another piece of evidence to the growing hypothesis, still up in the air, that the group began in the southeastern area of the US."
80 million years ago
Duck-billed dinosaurs were roaming the Earth some 80 million years ago. Also known as hadrosaurids, they were the most common herbivorous dinosaurs at the end of the Mesozoic Era, and all had similarly shaped snouts. Their jaws formed a beak shape used for cropping plants.
Aquilarhinus is the first evidence of a significantly different style of duckbill in a hadrosaurid — suggesting it may have also fed differently. The newly-identified dinosaur's lower jaws meet in a strange W-shape, creating a wide, flattened shovel-like scoop.