The legendary "Sphinx" eventually found its counterpart version in archeological fossil. Chinese and American paleontologists found two distinct kinds of bone characteristics in the fossil of a sharp-mouthed mammal excavated in northeast China's Liaoning Province. The mammal's upper part makes people believe it was viviparous while its lower part looks like oviparous, reports Wen Hui Daily.
The latest issue of the British magazine Nature reports the unprecedented discovery. The magazine editor as well as paleontologists marveled at the discovery and believed it might change the traditional theory on mammals evolution.
Li Gang, one of the coauthors of the paper, said the existing mammals are classified into two groups: the viviparous therian which have fully evolved bones such as kangaroos and elephants, and the oviparous monotreme which have comparatively primitive bones. The newly discovered fossil possesses the characteristics of both bones, a fact which won it the title of "world No.1".
Analysis of the fossil revealed that the mammal was 12 centimeters long and weighed about 15 to 20 grams. It lived about 120 million years ago in early Cretaceous period.
Further examination also found many evolutionary discrepancies. For example, it had the teeth of therians but also retained the lumbar ribs found only in primitive mammals.
So what is the explanation for this peculiar phenomenon of "lion body and human head"? Li Gang reasoned that the mammal finished synchronized evolution for both its upper part and lower part a long time ago. However, for some special survival need it had to let its evolved lower part to "retrogress" into a more primitive state.
(CRI, People's Daily, January 24, 2006)
