sharkdoctor Posted February 25, 2019 Share Posted February 25, 2019 Hi TFF, I'd love your help identifying the cetacean tooth pictured below. I found the tooth below while fossil hunting in eastern Virginia with @Gizmo. The tooth is from the base of the Claremont Manor member of the Eastover Formation. The color and condition indicate that it has been reworked from the underlying Calvert Formation. Thanks in advance for any help or comments! Link to comment Share on other sites More sharing options...
Fossildude19 Posted February 25, 2019 Share Posted February 25, 2019 @Boesse Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
SailingAlongToo Posted February 25, 2019 Share Posted February 25, 2019 It is my understanding there were no porpoises in the Miocene, especially in the Calvert Formation, so it's most likely a dolphin tooth. Don't know much about history Don't know much biology Don't know much about science books......... Sam Cooke - (What A) Wonderful World Link to comment Share on other sites More sharing options...
Boesse Posted February 28, 2019 Share Posted February 28, 2019 Porpoise/dolphin/whale have a range of very specific and very meaningless definitions and are best avoided in favor of clade names. This is a large odontocete, and is similar to Hadrodelphis - but quite a bit younger. Hadrodelphis is from the Calvert, zone 14. Nevertheless, I suspect this is perhaps another large bodied "kentriodontid" - early Delphinoidea. 2 Link to comment Share on other sites More sharing options...
Shellseeker Posted February 28, 2019 Share Posted February 28, 2019 The largest current Delphinidae is Orcinus, males are 30 feet long with 4 inch teeth. They qualify as LARGE!!! I do not think it is a good idea to go swimming with them. I am not clear on the wide range of sizes for the dolphin family. I am thinking medium sized is around 15 feet and small might be 7 or 8 feet. ALL are larger than me. Can anyone comment on the sizes of fossil dolphins? The White Queen ".... in her youth she could believe "six impossible things before breakfast" Link to comment Share on other sites More sharing options...
sharkdoctor Posted March 1, 2019 Author Share Posted March 1, 2019 Thanks, @Boesse! Link to comment Share on other sites More sharing options...
Boesse Posted March 2, 2019 Share Posted March 2, 2019 On 2/28/2019 at 6:48 PM, Shellseeker said: The largest current Delphinidae is Orcinus, males are 30 feet long with 4 inch teeth. They qualify as LARGE!!! I do not think it is a good idea to go swimming with them. I am not clear on the wide range of sizes for the dolphin family. I am thinking medium sized is around 15 feet and small might be 7 or 8 feet. ALL are larger than me. Can anyone comment on the sizes of fossil dolphins? In my vernacular description, anything bottlenose dolphin sized (2.5-4 meters) is medium; porpoises and down (<2.5 meters) is a small odontocete; anything between a pilot whale and a killer whale is large (5-10 meters) and anything over 10 meters is giant (=some beaked whales and the giant sperm whale). This gets shifted when talking about baleen whales: 2-5 meters is small; 5-10 is medium; 10-15 is large; 15+ is gigantic =) 2 Link to comment Share on other sites More sharing options...
Shellseeker Posted March 2, 2019 Share Posted March 2, 2019 The thought pattern that I started here relates to how I calibrate dolphin/whale teeth that I find and also those I see on this forum to approximate size of the marine mammal that produced the teeth. I am looking at @sharkdoctor 2.25 inch tooth, wondering the size of the mammal. Quote This is a large odontocete, and is similar to Hadrodelphis - but quite a bit younger. So, 5 meters is a possible length. I have a number of what seem to be marine mammal teeth from Bone Valley, Florida... Some are really small like Others are quite large. This is an unusually shaped tooth for Bone Valley in that I have seen nothing like it in Florida fossils, but it is badly beat up. At this tooth length, I think I am approaching an Orca sized Delphinoid . The White Queen ".... in her youth she could believe "six impossible things before breakfast" Link to comment Share on other sites More sharing options...
sharkdoctor Posted March 2, 2019 Author Share Posted March 2, 2019 Nice specimens, @Shellseeker! I would doubt a strict linear relationship (body length to tooth length) across species. If for no other reason than separate evolutionary pressures would be driving changes in tooth shape (and function) as well as body morphology. Outside of a strict linear relationship, I would expect a correlation (larger teeth tend to belong to larger individual animals). There are some other aspects that are peculiar to species. In the laminate teeth that you've pictured (probably a sperm whale or close relative for the larger one), one would expect the age of the individual to determine the size of the teeth ( see: https://www.icrwhale.org/pdf/SC013135-153.pdf ). In other words, the teeth continue to grow as the whale grows. However, it is my understanding that in critters like the Hadrodelphis type tooth that I posted, the tooth does not continue to grow throughout the animals life. The crown size and root size are set early in life and remain static. Link to comment Share on other sites More sharing options...
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