Washington: Paleontologists have discovered what they claim is the remains of the world's first known bug-eating dinosaur which sported just a single finger on each
of its hands and weighed just 450 grams.
The tiny one-fingered beast has been named 'Linhenykus monodactylus'. Linhenykus means "claw from Linhe", the city in Inner Mongolia near where the specimen was found in 2008, and monodactylus means "one-fingered".
This mini-predator is believed to have lived roughly 84 to 75 million years ago, and would have been just one pound, or 450 grams, in weight and may be 15 inches long from head to tail, LiveScience reported.
The beast doesn't count modern birds, which are dinosaurs that have modified the lone claws on each of their hands into part of their wings, the scientists said.
The evolutionary loss of fingers is often seen in the predatory dinosaurs, or theropods. For instance, while early theropods had four fingers on each arm, Tyrannosaurus rex -- one of the largest carnivores of all time -- had only two.
But, the newly discovered dinosaur kept only its index fingers, they said.
According to lead researcher David Hone, a palaeontologist at the University College Dublin in Ireland, the claws of Linhenykus were likely used for digging.
Its arm bones had adaptations "very similar to what you see in moles", Hone said.
These included attachment points on the bone for powerful muscles and bone shapes that could exert the kind of leverage needed for digging.
Linhenykus probably lost the use of its other fingers because "there is really not much that a multi-clawed hand would have done," Hone added.
"That one giant finger and claw is doing all of the work and the others are just kind of there."
According to the researchers, the site where the creature was found has a very hostile atmosphere.
"Forty to 50 degrees Celsius, no shade, and you are getting pelted with ice," Hone said, adding that they faced tandstorms and also a hailstorm at the site.
This new dinosaur likely once lived in open, scrubby desert, which could have been verdant around rivers.
"Its diet would be termites and possibly ants and probably any small insect if it came across it," Hone said.
The dinosaur's major predators would have likely included distant relatives such as Velociraptor, said the scientists who detailed their findings in the journal Proceedings of the National Academy of Sciences.
First Published: Wednesday, January 26, 2011, 09:52