A family of medium-sized iguanodontian dinosaurs called the Rhabdodontidae was one of the most important dinosaur groups inhabiting the ancient European Archipelago.
Inhabitants of the ‘Island of the Dwarf Dinosaurs’ in the Cretaceous Transylvania: Transylvanosaurus platycephalus (front right), as well as turtles, crocodiles, giant pterosaurs, and dwarf dinosaurs. Image credit: Peter Nickolaus.
Rhabdodontid dinosaurs inhabited the Late Cretaceous European Archipelago, an extensive archipelago with numerous small and large islands situated in a shallow tropical sea.
Currently, the family comprises nine species within six genera, which have been found in southern France, northern Spain, eastern Austria, western Hungary and western Romania.
Rhabdodontids were small- to medium-sized, probably habitually bipedal herbivores between 2 and 6 m (6.6-20 feet) in length.
They were characterized by a rather stocky build, with strong hind limbs, short forelimbs, a long tail and a comparatively large, triangular skull that tapers anteriorly and ends in a pointy snout.
“Rhabdodontids had a relatively robust skull with strong jaws, large teeth and a pointy beak that was covered in keratin, demonstrating that these dinosaurs were well-adapted to eating tough plants,” said University of Tübingen paleontologist Felix Augustin.
“In some instances, fossil remains of several individuals of different ages have been found together, indicating that they were gregarious.”
While rhabdodontids disappeared prior to the end-Cretaceous extinction event (about 69 million years ago) in Western Europe, they survived close to the end of the Cretaceous in Eastern Europe, where they were amongst the last non-avian dinosaurs still present before the end of the Cretaceous.
“The first rhabdodontid species was scientifically named more than 150 years ago,” Dr. Augustin said.
“Although the group looks back to a long research history, we still have much to learn about it.”
In their new paper, Dr. Augustin and colleagues reviewed the rhabdodontid taxonomic history, diversity, phylogenetic relationships and paleobiogeographic history, as well as paleoecology and extinction.
“Generally, our portraying of the world of dinosaurs is heavily biased towards the well-known North-American and Asian dinosaur faunas,” Dr. Augustin said.
“Dinosaur fossils from the Late Cretaceous are much rarer in Europe than in North America or Asia, and thus far no complete skeleton of a rhabdodontid has been described.”
“Even though they were so abundant and common in the Upper Cretaceous of Europe, several key aspects about them remain poorly known, including their detailed body proportions, their posture and locomotion, as well as their feeding behavior.”
“In the past decades, a wealth of new, and often well-preserved, rhabdodontid fossils has been discovered throughout Europe, the majority of which still remains to be studied.”
“A joint research project is currently underway to study the available fossil material in order to gain new insights into the evolution and lifestyle of these fascinating yet still poorly known dinosaurs.”