Wednesday, December 20, 2006
From BBC News UK: Scientists have found what is thought to be the first example of a two-headed reptile in the fossil record.
The abnormal animal, belonging to a group of aquatic reptiles, was unearthed in northeastern China and dates to the time of the dinosaurs.
The specimen reveals that it must have been very young when it died and became fossilised, says lead researcher Eric Buffetaut.
Details of the fossil appear in the UK Royal Society journal Biology Letters*.
This animal was a choristoderan**, an extinct reptile that reached a length of one metre in adulthood and was characterised by a long neck - two in this case.
Continued at "Two-headed reptile fossil found"
*Based on the paper "A two-headed reptile from the Cretaceous of China" (doi: 10.1098/rsbl.2006.0580)
A malformed embryonic or neonate choristoderan reptile from the Lower Cretaceous Yixian Formation of northeastern China is described. The tiny skeleton exhibits two heads and two necks, with bifurcation at the level of the pectoral girdle. In a fossil, this is the first occurrence of the malformation known as axial bifurcation, which is well known in living reptiles.
**Info on Choristodera:
Choristodera is an order of semi-aquatic diapsid reptiles which ranged from the Middle Jurassic, or possibly Late Triassic, to upper Eocene, or upper Oligocene. Choristoderes have been found in North America, Asia, and Europe. The most common fossils are typically found from the Late Cretaceous to the lower Eocene. Cladists have placed them between basal diapsids and basal archosauromorphs but the phylogenetic position of the Choristodera is still uncertain. It has also been proposed that they represent basal lepidosauromorphs. Most recently, workers have placed Choristodera within Archosauromorpha.
An earlier post (Wednesday, September 20, 2006):
Snake With Two Feet Appears in Shandong, China
The Epoch Times (New York): China - On September 11, 2006, Mr. Ma, a resident in Linyi city, Shandong province, displayed to the public a snake with two feet.
Ma caught the snake Sept. 10. It was about one meter long, as thick as an adult's thumb, and with a triangular shaped head. The strange thing about it was, it had two, one-centimeter-long five-toed feet on each side of its body about 30 centimeters from its head.
After seeing the snake, Professor Cao Shandong from the School of Life Science Linyi Normal University said, it was a twin-spotted rat-snake, but the feet and toes were extremely unusual. Professor Cao said it could be a case of atavism. [Evolution]