Posted by:
CKing
at Fri Oct 23 17:55:49 2009 [ Report Abuse ] [ Email Message ] [ Show All Posts by CKing ]
Those who are interested in the origin of snakes may be interested in the following paper:
http://www.kingsnake.com/aho/pdf/menu3/rickshine/originofsnakes.pdf
This paper investigates eye anatomy and found that snake eyes share many characteristics with those of aquatic vertebrates, suggesting and corroborating earlier phyologenetic analyses and fossil data linking snakes with marine reptiles called mossasaurs. The oldest known snake fossils had legs, and they were marine animals. These snakes also had the macrostomatan condition. Therefore the microstomatan snakes likely evolved their fixed jaws and small gapes secondarily from a macrostomatan condition. Indeed, detailed investigations of different microstomatan snakes show that their jaws are highly speciliazed and differ markedly from those of lizards, and therefore supportively of derived, rather than primitive conditions. Snakes therefore appeared to have evolved in the marine environment and the blind and burrowing snakes evolved later from marine ancestors.
[ Reply To This Message ] [ Subscribe to this Thread ] [ Show Entire Thread ]
|