Paleontologists have discovered a new species of medium-sized herbivorous dinosaur that lived in Antarctica near the end of the Late Cretaceous Epoch, around 70 million years ago (see International Chronostratigraphic Chart).
The new species, Morrosaurus antarcticus, is known from the right hind limb of a single individual. The fossils were collected from a geological layer known as the Snow Hill Island Formation on James Ross Island. The area also produced a variety of fossils of marine animals, including invertebrates and plesiosaurs.
The genus name of the new dinosaur refers to El Morro, the locality where the fossils were found. The species name refers to the dinosaur’s presence in Antarctica.
The scientific paper describing Morrosaurus has been published online in the journal Cretaceous Research. The study was carried out by a team of Argentinian paleontologists led by Sebastián Rozadilla of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia.”
Morrosaurus is a member of a dinosaur group called Ornithopoda, which includes small bipeds and large quadrupeds, such as the duck-billed hadrosaurs. The authors analyzed the evolutionary relationships of Morrosaurus and found that it forms a group with other small to medium-sized ornithopods from the Southern Hemisphere, including a fellow Antarctic ornithopod called Trinisaura.
This group also includes the Argentinian ornithopods Gasparinisaura, Anabisetia, Notohypsilophodon, Talenkauen, and Macrogryphosaurus. This finding adds evidence that, during the Cretaceous Period, Antarctica and Argentina shared unique dinosaur fauna.
Morrosaurus is distinguished from its close relatives by four anatomical features on its hind limb bones.