A few stacked images of one of my favourite shark's teeth from the Late Cretaceous (Albian through Campanian). The tooth's highly specialised shape/structure draws interesting parallels with the (marine) reptilian tooth from a couple of earlier posting of mine, see: Globidens aegyptiacus - extraordinary prey crushing tooth and Globidens aegyptiacus (2) - deadly wrinkles.
Like the marine reptile G. aegyptiacus, the ancient shark P. whipplei also fed on hard shelled prey. The teeth of both animals (reptile and fish) are beautifully adapted for their purpose, although the teeth of P.whipplei were not arranged along the jaw edge (like G. aegyptiacus) but were grouped into plates located centrally towards the front of the mouth (top and bottom).
There are a number of Ptychodus species however the tall, almost vertical central part of the crown identifies this tooth to the species P. whipplei.
Check out these websites for more information on Ptychodus sp.
http://www.oceansofkansas.com/Ptychodus.html
http://www.oceansofkansas.com/tom_c.html
http://www.elasmo.com/genera/cretaceous/ptychodus.html
Photos taken with Meiji EMZ-5TR
Bruce
*Side-on view looking from the front (15 stack):
*View from top with front of mouth at bottom of page (16 stack):
*Close up of biting point showing internal reticulated structure. Note: we are looking throught a layer of transparent enamel (14 stack):
