A bizarre-looking dinosaur discovered by a young boy in Chile may be the missing link showing how members of one major dinosaur lineage evolved into a completely new dinosaur group, a new study finds.
Researchers in the United Kingdom say the species, dubbed Chilesaurus diegosuarezi, explains how some theropods, mostly meat-eating, bipedal dinosaurs, evolved into the herbivorous, long-necked ornithischians.
Previously, it was unclear how the “ornithischian group just suddenly appeared and became this well-adapted herbivorous group,” said the study’s co-lead researcher, Matthew Baron, a doctoral student of paleontology at the University of Cambridge in England. “There was no intermediate step. This is the first one we’ve found.” [See Photos of the Missing Link, Chilesaurus diegosuarezi]
If future research confirms this finding, this would make Chilesaurus the earliest member of Ornithischia, a group that includes the armored dinosaurs, such as Stegosaurus and Ankylosaurus, as well as horned dinosaurs, such as Triceratops.
But not everyone is on board with this interpretation. Rather, more “grunt work” is needed to determine Chilesaurus’ true identity, said Thomas Carr, an associate professor of biology at Carthage College in Wisconsin and a vertebrate paleontologist. Carr was not involved in the study.
This isn’t the first time Chilesaurus has turned heads. In 2010, 7-year-old Diego Suárez, the son of two geologists, found the 145-million-year-old beast in southern Chile’s Toqui Formation.
After Diego found the first specimen, excavations in Chile yielded more than a dozen Chilesaurus individuals, including four complete skeletons that ranged from turkey-size young dinosaurs to nearly 10-foot-long (3 meters) adult dinosaurs. But despite the abundance of fossils, Chilesaurus’ anatomy was a real head-scratcher.
The creature looked like a mixture of lineages. It had the long neck, small skull and clunky feet of a sauropodomorph (a group of long-necked, herbivorous dinosaurs with lizard-like hips); the beak, teeth and pubic bone of an herbivorous, bird-hipped ornithischian; and the bipedal stance, robust forelimbs and ilium (the upper part of the pelvic bone) of a meat-eating theropod.
To determine where Chilesaurus fit in the dinosaur family tree, the South American researchers looked at four data sets to compare the dinosaur’s features with…