In the journal Zootaxa, a team led by Xing Xu of the Chinese Academy of Sciences reports, Xixianykus zhangi ('SHEE-shya-nye-kus jong-eye') describes a pint-sized, two-legged sprinter from about 85 million years ago. The fossil's legs, hips and backbone adds to growing evidence that the dinosaur's "parvicursorine" kindred, "represent extreme cursors (runners) among non-avian dinosaurs," says the study.
""The limb proportions of Xixianykus are among the most extreme ever recorded for a theropod dinosaur," says study researcher Corwin Sullivan, also of the Chinese Academy of Sciences, in a statement. "This doesn't provide a basis for estimating its top speed, but it does show that Xixianykus was a highly efficient runner."
The dinosaur's name derives from Xixia, its region of origin, onyx (Greek for claw) and specific name in honor of paleontologist Zhang Wentang, "who has contributed greatly to the study of paleontology in Henan Province," according to the statement.
The relatively short thigh-bone of the dinosaur, which stood perhaps 20 inches tall, hints that it was a digger, as well as a runner, says the study. Termites dug from the ground with its claws likely made for meals for Xixianykus. "It may sound odd, but digging and running actually work quite well together. Some modern termite eating species travel long distances between colonies of their prey, so as an efficient runner Xixianykus would have been able to follow this pattern," said co-author David Hone of the Chinese academy.
"Wood-nesting termites may have essentially represented a patchy resource for these dinosaurs, forcing them to travel considerable distances between colonies and(or) spend long periods searching for food, as is apparently true of aardvarks and giant anteaters today," concludes the study.
Running would definitely have been a good skill too, Hone adds. Xixianykus lived in the era of Tyrannosaurus Rex and kin, a bad time to be small and slow.