Is there any evidence to show who sharks evolved from

[Keithzworld]

n/t

[Tank]

Should that be a 'what' rather than 'who' in the title?

The whole fossil record of the shark/ray family is sketchy as the majority of the skeleton is formed from cartilage rather than bone. Cartilage is soft and easily decomposed and thus fossilises very badly. However the jaws are reinforced with calcium and thus are bone to they do provide a route to the sharks ancestral species, there teeth also fossilise very well.

Here are a couple of links that may be of interest.

http://www.fossilguy.com/topics/megshark/megshark.htm
http://www.nhm.ac.uk/nature-online/life ... index.html
http://www.sharkiologist.com/article_sh ... ution.html