Researchers uncovered at least one footprint so clear it can be matched for the first time to skeletal remains of a new species of titanosaur that's found in the same region of Argentina.
The hundreds of new titanosaur tracks found at the Agua del Choique site, in the Mendoza Province, are revealing secrets about how titanosaurs walked. The tracks also provide clues about other dinos, which strolled along muddy paths near the shores of a small, new sea that grew to become the Atlantic Ocean.
The most telling titanosaur track discovered at the site belonged to an animal estimated to have been a mid-sized titanosaur: some 7 1/2 feet (2.29 meters) high at the hip and 40 to 45 feet (12 to 14 meters) long. The largest-known titanosaurs, Argentinosaurus, are thought to have ranged from 100 to 130 feet (30-40 meters) long and up to 24 feet (7.3 meters) high.
“Most sauropod tracks simply look like post holes,” said paleontologist Spencer Lucas, curator at the New Mexico Museum of Natural History and Science in Albuquerque who was not involved in the discovery. “Tracks in which you can see digit imprints are rather rare, so (it's) a remarkable tracksite for sauropod tracks.”
“Although other studies have documented impressions of digits or claws in titanosaurs, they are poorly defined” and don't reveal much useful information that can be compared to fossil bones, explained Bernardo Javier González Riga of Argentina's National University of Cuyo.
Riga and his colleagues are publishing their discovery of the matching track and fossil in the August 2015 issue of the Journal of South American Earth Sciences.
“Anatomically, the record of (intact) and complete (hind feet) is really scarce in titanosaurs,” Riga reported. In fact, of the 65 species of titanosaurs known worldwide, only three have intact fossils of their feet, he writes.
That's not to say that the bones belonged to the same individual that made the tracks -- they're not only far apart in space, but also in time. But they do belong to a similar titanosaur.
“Not all tracks can be matched to specific skeletons because foot structures do not vary that much in some dinosaur groups,” Lucas said. “Relatively few dinosaur tracks have been matched with certainty to a dinosaur (type). Sometimes, the bones from one rock formation are claimed to represent the trackmaker of tracks in the same formation, but even this is not often a certain link.”
Among the other things revealed by the trackways are just how fast some of the titanosaurs walked across the muddy ground they encountered in the late Cretaceous.
Read more at Discocvery News
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