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Here are two links to posts dealing with how to post pictures on Black River Fossils forums.
1. How to Post Pictures on Black River Fossils Forums by ditchweezil
2. How to Post Pictures on Black River Fossils Forums by Daryl
Tom,
Although evolution does happen over time and does happen in a specific formation typically you don't find teeth with different traits in different zones of the formation. The nanjemoy formation for example when the otodus transitioned to the ric in one zone you have otodus then the next you have teeth that are barely serrate then the next zone has the aksuaticus then the next has ric's. Rarely do you find a tooth out of position. You also have the same things with the mako evolution to great white in peru where one zone has makos the next barely serrate ones and so on.
Martijn,
The partially serrate teeth i have for late calvert are not escheri's they most likely xiphodon. The interesting thing is that they are juveniles and they have side cusps just like a juvenile great white. The Plum Point area does have some choptank so it is possible that my partially serrate teeth where the beginning of the evolution in the late calvert and the tooth you have is the finish of the transition a couple million years later in the choptank. Who knows at this point.
I have attached a front and back image of one of the teeth
Carl, you're right, but since Bay teeth are usually not found in their original locations, but are instead found in the water or on the beach, I wasn't too worried about which zone any possible Great White teeth may have come from. Besides, I have a more interesting question to ask. According again to Kent, GWs can be found in the Calvert, Eastover, and Yorktown formations. How can the species be present in the Calvert but not the Choptank, considering that the two formations are chronologically sequential and are in physical contact?
Might be worth emailing Dr Kent for an explanation.
Tom
If GW's came from Mako's "over time", then why are there still mako's, and why aren't they slowly getting serrations? It seems like the only evidence for something evolving has to be the tooth changing from non-serrated to eventually fully serrated. Does this mean sand tigers need to develop serrations, or any other shark that doesn't have them?
Daryl.
I actually did email Dr Kent about this subject, about a week ago, but haven't heard back from him yet.