(Leaping) Limbless Lizards!
ScienceDave | May 28, 2007 at 03:02 pmby
1627 views | 4 Recommendations | 3 comments
The slithery species looks more like a snake than a lizard, but such is the case for some species belonging to the Scincidae family of lizards, also known as “skinks”. Over 30 species of skinks have undergone partial or complete limb loss, including Brachymeles, Isopachys, Typhlosaurus ,and Acontias. This particular species has tentatively been placed in the Sepsophis genus, a group containing other limbless lizards.
"The lizard is new to science and is an important discovery. It is not found anywhere else in the world," Dutta told The Associated Press…
...While modern snakes and lizards are derived from a common evolutionary ancestor, they belong today to two entirely separate groups of animals, or orders. Snakes, over millenia, gradually lost their limbs and developed their characteristic forms of locomotion. But modern limbless lizards are not snakes, Dutta said
How did these evolutionary distinct groups come to possess a common phenotype (i.e. physical form)? Well, typically when things are lost in biology, it is to specialize at doing something no one (or at least not many) other species are doing. For example, would large ears be beneficial for burrowing or would they get caught on debris? The same could be argued for legs: it costs less energy to burrow a smaller hole for a legless individual than a legged one. Essentially, this is the contending hypothesis for snakes evolving from lizards during the Paleocene, approximately 65 million years ago (although another hypothesis exists that is less convincing at present).
As exciting as this new discovery may be, it has yet to be published in a peer-reviewed journal. Thus it still remains to be fully described and annotated with respect to its closest genetic relatives.
Another species of the same genus, "Sepsohis punctatus," was found in 1870 from the Golconda hills in Andhra Pradesh, said Varadi Giri, a scientist at the Bombay Natural History Society, who was not part of the team that found the lizard. Giri said Dutta is a reputed zoologist and his claim appears legitimate. "But for an independent confirmation, one has to wait for the publication of the finding in a reputed science magazine."
Brian A KennedyThese members have powered this story: