During his daily walk seven years ago, retired refrigerator repairman Tolentino Marafiga spotted some unusual bones poking out of a road construction site in southern Brazil. It was a major find, paleontologists say: a new dinosaur species, one of the most primitive ever found.
The reptile walked on Earth 200 million to 225 million years ago, in the late Triassic, when dinosaurs were rare and new. Eight feet long and only 155 pounds, the lithe forest dweller was a delicate ancestor of the sauropods, the largest land animals that ever lived.
Like the most famous sauropod giant, Brontosaurus, the new dinosaur fed on plants, says Artemio Leal of Brazil’s National Museum in Rio de Janeiro and lead author of the paper describing the find. A biped, it probably moved through conifer forests in a herd, shearing off bits of ferns and palmlike cycads with its serrated, spatulate teeth, suggests Leal.
The biggest surprise is that Unaysaurus tolentinoi, named for its discoverer, was a close cousin of dinosaurs found in what is now Germany. This bolsters the prevailing concept that all the world’s continents were once jammed together as a single giant landmass called Pangaea.
Also intriguing is the dinosaur’s well-preserved skull, with depressions and protrusions not seen before. The novel features helped paleontologists determine that the dinosaur was a new species but raised other questions in the process, says Alexander Kellner, the paper’s coauthor. “Sometimes paleontologists observe anatomic differences but cannot explain what their purposes were.”