Long, long ago, some of the first dinosaurs walked the Earth. But scientists have not known with any confidence where those initial dino prints were made. Much more recently, hikers stumbled across a few bits of bone at Ghost Ranch in New Mexico, leading to the discovery of a game-changing dinosaur that reveals where it all began.
The dinosaur, now called Tawa hallae, had a body that was only the size of a medium to large dog, but its remains have helped scientists shore up where dinosaurs came from. The research team used the extremely well-preserved and complete skeletal remains as a means to fitting the newbie and other early dinosaurs onto the evolutionary tree.
"[The results] showed a lot of the South American dinosaurs in the Triassic were the most primitive dinosaurs we have found to date," said lead researcher Sterling Nesbitt of the University of Texas at Austin. "They are closest to the common ancestor of all dinosaurs." (Nesbitt was at the American Museum of Natural History in New York when he made the discovery.) ....
...The excavated skeletons suggest this species had a snout-to-tail tip length of about 6 to 13 feet (2 to 4 meters), with a hip height of 3 to 5 feet (1 to 1.5 meters). The bones suggested that when alive, T. hallae was equipped with air sacs surrounding its neck and braincase
