"Thunder thighs" dinosaur discovered

Science Fair: "Thunder thighs" dinosaur discovered

A international paleontology team reports the discovery of a "thunder thighs" dinosaur, a big, brawny, and four-legged sauropod, discovered in Utah quarry rocks dating to 110 million years ago.

At least two specimens, perhaps a mother and her offspring, have been uncovered of Brontomerus mcintoshi, or "thunder-thighs", the new species described in the journal Acta Palaeontologica Polonic a by the team led by Michael Taylor of University College London. Brontomerus was a sauropod, four-legged, long-necked and long-tailed, and the larger specimen would have weighed six tons while alive and measured more than 45 feet long.

"Brontomerus mcintoshi is a charismatic dinosaur and an exciting discovery for us," said Taylor, in a statement. "When we recognised the weird shape of the hip, we wondered what its significance might be, but we concluded that kicking was the most likely. The kick would probably have been used when two males fought over a female, but given that the mechanics were all in place it would be bizarre if it wasn't also used in predator defense."

Brontomerus is remarkable for its robust thighbones, the team notes in the study, also suggesting the dinosaur may have kicked at "raptor" dinosaurs that sought to prey on the species.

Compared to other North American sauropods, the discovery points to this type of vegetarian dinosaur shifting its population characteristics in the later stage of the Age of Dinosaurs, as the Jurassic gave way to to the Cretaceous era about 144 million years ago:

"The improving record of Early Cretaceous sauropods in North America is extended by the new genus, so that generic−level diversity of sauropods in this epoch now approaches that of the Late Jurassic. The most striking differ−ences between Late Jurassic and Early Cretaceous sauropods in North America is that the former are abundant and dominated by diplodocids, whereas the latter are comparatively scarce and dominated by macronarians. It is currently impos− sible to determine whether this shift happened suddenly, or gradually over many millions of years in the earliest Creta ceous. It is natural to assume that if the shift was sudden, it happened at the end of the Jurassic, but that is not necessarily the case. The timing and tempo of this faunal shift remain un−certain; future inferences will have to be based on improved understanding of global changes in conditions in the earliest Cretaceous, and careful analysis of faunal changes on neighbouring continents, especially Europe," says the study.