Northern Sharks Posted November 29, 2007 Share Posted November 29, 2007 I just got this piece yesterday for the simple reason that it has a lot of bite marks for a small piece, and a couple of them clearly show serration marks. The best of them is near the top on the right side in my pic. Is it possible to identify what animal this came from based on a small bone fragment such as this? (I was told it was manatee) Secondly, this came from the St Marks river in Fl. What age is the material coming from this location? Thanks in advance. There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Harry Pristis Posted November 29, 2007 Share Posted November 29, 2007 It will be impossible to say what this bone scrap is from, except "mammal." Who can say whether this bone is from an Early Miocene (St. Marks Fm) whale or from a Pleistocene bison carcas (a "floater') washed into the proto-Apalachee Bay. I have found Pleistocene fossils in the St. Marks, including a bison horncore. This does give you a range of time for the bone, though. It's no earlier than Early Miocene and no later than Late Pleistocene (Rancholabrean). The probability is that the bone is later, rather than earlier in this range. Manatee is certainly possible, but so is a wide variety of large mammals. I have found the occasional Mio-Pliocene dugong rib with tooth marks in the Peace River of Southcentral Florida. I deduce that it is dugong, not whale, because dugong ribs are much, much more common than whale bones. I don't have room in my drawer for this fossil; and, if you like it, it can be yours. ----------Harry Pristis 1 http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Northern Sharks Posted November 29, 2007 Author Share Posted November 29, 2007 Thanks Harry for the info. I didn't think a piece that small could be positively id'd. As for what type of shark left the serration marks, my best guess would be a Tiger or possibly a large Great White. They seem to be spaced too far apart to be a Meg. I know GW's are a rare find in Florida in general, but what species are typical of that river? There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Members geofossil Posted November 29, 2007 Members Share Posted November 29, 2007 Northern sharks. It's an interesting question you bring up. Why would this bone be manatee? I have to agree with Harry. I'd go a little further and question the legitimacy of a person's knowledge who could identify a 'fragment' of bone to a specific group. I see the the same 'stretch' of identification with the identification of dino bone. A complete distinct bone might be diagnostic....even then there can be a continuum between between families. A question for Harry on shark predation marks. We find dino bones with predation marks on them.....probably carnivorous dinosaurs. The teeth of these theropods were serrated but there is never any indication of serrations in the marks. Does a shark with serrated teeth make a bite that leaves a series of serrations? A dino is thought to basically 'take a rip' out of the prey animal and then the chunk goes 'down the hatch'. The following is typical...parallel gashes from adjacent teeth but not rows of striations from some sideways force from the bite from a specific tooth. Link to comment Share on other sites More sharing options...
Northern Sharks Posted November 30, 2007 Author Share Posted November 30, 2007 I'll jump in first on this one. I have about a dozen different bones showing predation bites. All my others are similar to yours Geo, with a gash or 2 relatively parallel. I would think that with both shark and prey thrashing about in the water, sooner or later a tooth will drag along the surface of the victims bone and leave serration marks. Definately not the most common things as I've only seen a couple of others (I've got another on the way) compared to dozens of "regular" bite marks. When I get time, I'll put together an album of my "meals" There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Northern Sharks Posted November 30, 2007 Author Share Posted November 30, 2007 Another thought here. From what I've seen, the serrations on dino teeth are quite fine, similar to a Meg. Any marks left on a bone wouldn't be too deep and may have eroded over the millions of years. By comparison the serrations on a Tiger shark or a Hemipristis (also a possibility for what bit my piece) are fairly large and coarse and marks they made might be deep enough to last until now. Are there any dinos that had larger serrations? There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Xiphactinus Posted November 30, 2007 Share Posted November 30, 2007 I have some large fish that have scrapes on them. Also, there are shed Squalicorax teeth (serrated) with the bitten bones, but very few indications of serrations on the bites themselves. So I'd say that a lack of serrations on a bite is not a 100% indication of non-serrated teeth. Link to comment Share on other sites More sharing options...
Harry Pristis Posted November 30, 2007 Share Posted November 30, 2007 There is a fundamental difference in the tooth attachments of dinosaurs and sharks. Dinosaur teeth are held rigid in a boney jaw. Shark teeth are held more loosely, bound to the jaw by fibrous tissue. Frazzetta in his Feeding Mechanisms of Sharks and Other Elasobranchs (1994) found that Carcharodon and carcharhinids had teeth that could rotate from 20 to more than 40 degrees around their undisturbed position. Scraping a tooth laterally along a bone might not break or dislodge a shark tooth as easily as such a lateral force might snap a dinosaur tooth. I'm sure such accidents happened many times. And, they would be accidents because dinosaur and shark teeth are optimized for shearing flesh rather than for scraping flesh from bone. ---------Harry Pristis 1 http://pristis.wix.com/the-demijohn-page What seest thou else In the dark backward and abysm of time? ---Shakespeare, The Tempest Link to comment Share on other sites More sharing options...
Northern Sharks Posted December 1, 2007 Author Share Posted December 1, 2007 I've just created a gallery album of my bite damaged bones. While I don't expect as many comments as Mike Owens has gotten lately :o please let me know if something is misidentified or if you can id something I'm unsure of. Enjoy There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Mike Owens Posted December 1, 2007 Share Posted December 1, 2007 Yeah, I do believe the 4MM+ is gonna be hard to beat. What's amazing is it went from 7 comments to the 4MM+ in 24 hrs. No wonder Anson is having problems with the postings. :lol: -----"Your Texas Connection!"------ Fossils: Windows to the past Link to comment Share on other sites More sharing options...
Gatorman Posted December 1, 2007 Share Posted December 1, 2007 ok I fixed the numbers that was weird. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now