London: Scientists have identified a new dog-sized dinosaur species from South America that roamed the Earth in small groups and lived on a diet of ferns and insects.
The species, named Laquintasaura venezuelae, was identified with the help of 200-million-year-old fossils from the La Quinta Formation in Venezuela.
Bones from at least four Laquintasaura were found together, with individuals ranging in age from three to approximately 12 years old.
It is possible they lived in small groups, making it the earliest example of social behaviour in ornithischians, `bird-hipped` dinosaurs, a group which includes species such as Stegosaurus and Iguanodon.
Laquintasaura walked on two hind-legs and was about the size of a small dog, measuring one metre in length and 25 centimetres at the hip, according to scientists from the Natural History Museum in the UK and the University of Zurich.
It is thought to have been largely herbivorous, feeding on ferns, but long curved tips on some of its teeth suggest it might have also eaten insects or other small prey.
"Laquintasaura lived very soon after the major extinction at the end of the Triassic Period, 201 million years ago, showing dinosaurs bounced back quickly after this event," said Dr Paul Barrett, lead author and palaeontologist at the Natural History Museum.
"It is fascinating and unexpected to see they lived in herds, something we have little evidence of so far in dinosaurs from this time.
"The fact that it is from completely new and early taxon means we can fill some of the gaps in our understanding of when different groups of dinosaurs evolved," Barrett said.
"The early history of bird-hipped dinosaurs is still very patchy as so few of them have been found. This early species plays a key role in our understanding of the evolution, not only of this group, but of dinosaurs in general," said Professor Marcelo Sanchez-Villagra, co-author and palaeontologist at University of Zurich.
The study was published in Proceedings of the Royal Society B.