Researchers have unearthed numerous teeth, hip, and leg bone fragments that belong to a new dinosaur species they’ve now named Laquintasaura venezuelae. It’s the first dino found in the north of South America.
The 201-million-year-old fossils belonging to at least four Laquintasaura individuals were discovered in Lower Jurassic sediments of the La Quinta Formation of the Venezuelan Andes. The newly discovered dinos are early members of a group known as the ornithischians -- or “bird-hipped” dinosaurs -- which later would give rise to Stegosaurus, Iguanodon, and Triceratops. The other major order of dinosaurs are called saurischians, or “lizard-hipped” dinosaurs, and these include T. rex and Diplodocus. (Interestingly, birds evolved from these guys, not the bird-hipped ones.)
An international team led by Paul Barrett from the Natural History Museum in London described the new species in Proceedings of the Royal Society B this week. Laquintasaura walked on its two hind legs and was about the size of a small dog. The largest femur found was 90 millimeters long, suggesting that the bipedal dinosaur’s total body was about one meter in length and 25 centimeters tall at the hip.
“The early history of bird-hipped dinosaurs is still very patchy as so few of them have been found,” explains study author Marcelo Sánchez -Villagra from the University of Zürich. By analyzing the residual radioactivity of tiny crystals within the rock, the team revealed that Laquintasaura lived 201 million years ago -- soon after a major extinction event at the end of the Triassic Period. This was one of the greatest mass extinction events, wiping out at least half of the species living on Earth at the time. These new fossils show just how quickly dinosaurs bounced back after the event. Additionally, Laquintasaura lived in the equatorial region, which was previously thought to be too tropical and inhospitable for these sorts of dinosaurs.
“There are many surprising firsts with Laquintasaura,” Barrett explains in a news release. “Not only does it expand the distribution of early dinosaurs, its age makes it important for understanding their early evolution and behavior.”
These newly discovered individuals ranged between three to about 12 years old. The researchers think they were largely herbivorous, feeding on ferns, though the long curved tips on some of their teeth suggest that they also may have eaten insects and other small prey.
Because four individuals were found together, the team believes Laquintasaura lived in small groups, making this the earliest example of social behavior in ornithischians, “It is fascinating and unexpected to see they lived in herds,” Barrett adds, “something we have little evidence of so far in dinosaurs from this time.”
The genus name comes from “Laquinta” after the horizon in which it was found, and “saura,” which is Greek for lizard. The species is named for the country and people of Venezuela.
Images: Mark Witton (top) & Adrian Ritter and UZH (middle)