BIG BEND NATIONAL PARK, Tx (PRESS RELEASE) – Fossils discovered 35 years ago in the Big Bend National Park have recently been identified as a new dinosaur species, Aquilarhinus palimentus.
This duck-billed dinosaur is known for its aquiline nose and wide mandible, shaped like two trowels laid side by side.
The fossil was originally discovered in the 1980s by Professor Tom Lehman of Texas Tech University. The bones were badly weathered and stuck together so that they could no longer be studied. Investigations in the
1990s revealed two domed nasal ridges, which were believed to be characteristic of the genus Gryposaurus. At that time, the peculiar lower jaw was recognized, but only recently did the researchers find that the specimen was more primitive than Gryposaurus and all other duckbill saurolophid dinosaurs.
"This new animal is one of the more primitive hadrosaurids known and can therefore help us to understand how and why the ornamentation has developed on their heads and where the group originated and from where they migrated ", says senior author Dr. Albert Prieto-Márquez from the Institut Català de Paleontologia Miquel Crusafont, near Barcelona. "Its existence is further evidence of the growing hypothesis that the group began in the southwestern United States."
Dinosaur beaked dinosaurs, also known as hadrosaurids, were the most common herbivorous dinosaurs at the end of the Mesozoic era, and all had a similar-looking muzzle. The front of the jaw meets in a U-shape to support
a hollow beak that is used to grow plants. The beak of some species is wider than others, but there was no evidence of a significantly different shape (and therefore probably a different feeding style) until Aquilarhinus was discovered. The lower jaws of Aquilarinus meet in a special W-shape and form a broad, flattened ball. About 80 million years ago, this particular dinosaur
would have paddled through loose, moist sediment to scoop loose-rooted aquatic plants from the tidal swamps of an ancient delta that today houses the Chihuahuan Desert.
The Importance of This discovery implies that the jaw and other characteristics of the specimen show that it does not fit the group of duckbilled dinosaurs known as Saurolophidae.
It is more primitive than this group, suggesting that there may be more primitive species than previously recognized. Saurophids had a skull crest and the current specimen also had a bony crest shaped like a humpbacked nose. The discovery of a solid comb outside the group supports the hypothesis that both types of combs are descended from a common ancestor.
These findings have recently been published in the Journal of Systematic Paleontology and are available at http://www.tandfonline. com / 1
The work was carried out with the approval of the Big Bend National Park and the Texas Vertebrate Paleontology Collections at the University of Texas at Austin, where the specimen is located.
ILLUSTRATION OF ICRA ART