Queer dinosaur fossil in China reveals they got big in Asia before America

November 14th, 2007 - 1:48 am ICT by admin  
The newfound species belong to a group of large dinosaurs called therizinosaurs, relatives of meat-eating theropods like Tyrannosaurus Rex.

Therizinosaurs had long necks, small heads, wide bodies, and unusually short tails. They also had large and powerful forelimbs that were tipped with three sharp claws.

However, unlike most other theropods, which were meat-eaters, therizinosaurs were vegetarians.

“These are without doubt some of the strangest dinosaurs ever found. They looked kind of like a gigantic plucked turkey. They adapted themselves to eating plants full time, and as a result their bodies became modified in very, very unusual ways compared to other theropods,” said Matt Lamanna, a palaeontologist at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.

Lamanna said the claws were most likely used to fend off predators and may have also played a role in pulling tree branches toward their mouths, as in their namesake giant ground sloths.

The earliest known therizinosaurs date to 125 million years ago and have been found in eastern China and western North America.

Though scientists are unsure where these dinosaurs first evolved first, they believe they likely migrated between the continents on land bridges that periodically appeared millions of years ago.

Lamanna said the new specimen dates to about 115 million years ago and is the oldest large therizinosaur known. The earliest large therizinosaur known from North America is Nothronychus, which dates to about 90 million years ago.

He said the new Gobi dino, named Suzhousaurus megatherioides was about 22 feet (6.7 meters) long, 7 feet (2.1 meters) tall at the hips, and weighed between one and two tons.

He added that the new fossil, discovered in 2002 but named only now, indicated that Asian therizinosaurs reached their large size much before their North American counterparts did.

“Within ten million years of therizinosaurs’ first appearance, they began to grow large, perhaps for protection or to better digest more plant food. We’re not sure, but it does tell us that [this group] attained large size very rapidly after they first appeared,” Lamanna said.

“It suggests that regardless of which continent they originated in, [therizinosaurs] got big in Asia before they got big in North America,” National Geographic quoted Lamanna as saying.

Lamanna and his colleagues describe Suzhousaurus megatherioides, which means “giant sloth-like lizard from Suzhou,” in the current issue of the Chinese journal Acta Geologica Sinica. (ANI)

Related Stories

Posted in Sci-Tech |