siteseer Posted December 1, 2017 Share Posted December 1, 2017 I thought I would bring in the forum on a difference of opinion among a few collectors. Attached are views of a specimen identified as a Metaxytherium tusk (late Miocene, Bone Valley Formation, unnamed phosphate mine, Polk County, Florida) by one experienced Florida collector and another collector familiar with a range of marine mammal fossils. Two other experienced Florida collectors leaned toward an ID of whale tooth. The specimen resembles one in Domning (1988: p. 409, fig. 7) which was identified as a Metaxytherium tusk. The specimen in question is straight like a tusk with an enamel-coated crown with a constriction toward the tip as in the figure. I've looked for a similar specimen labelled as a whale tooth in various publications (Richard Hulbert's "Fossil Vertebrates of Florida; the Lee Creek volume that covers mammals, etc.) but couldn't find one. Metaxytherium was a "sea cow" or dugong relative that lived during the Miocene - a time when sea cows were more diverse and widespread than they are today. The Florida collector who thought it was a Metaxytherium tusk pointed out the enamel texture and its laterally-compressed overall form was the same as a tusk. The other Florida collectors didn't point out any particular feature to count it out as a Metaxytherium tusk - just didn't look right to them. I can understand having difficulty articulating an overall impression. Those two guys know Florida fossils so I respect their opinions. I'm interested in reading what other collectors think - especially all the Florida/Bone Valley collectors out there. I'll try to get a scan of the figure in the Domning article and attach it - couldn't find a pdf in a quick search. Thanks, Jess Domning, D. P. 1988. Fossil Sirenia of the West Atlantic and Caribbean region. I. Metaxytherium floridanum Hay, 1922. Journal of Vertebrate Paleontology 8:395–426. 1 Link to comment Share on other sites More sharing options...
Miocene_Mason Posted December 1, 2017 Share Posted December 1, 2017 Well I’m not from there and I’m not sure about all this Metaxytherium tusk business (I didn’t know they had tusks) but that look a lot like a whale tooth to me. If there is someone to settle the matter I suppose it would be @Boesse “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
Harry Pristis Posted December 1, 2017 Share Posted December 1, 2017 Anything helpful here? dugongid_dentition.pdf 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...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 a while back I posted an excerpt from this: 1 Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 from 1994(edit:I'll let it stand,although it might be considered (minor)threadjacking) 1 Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 3 Link to comment Share on other sites More sharing options...
Boesse Posted December 1, 2017 Share Posted December 1, 2017 This looks dugongid to me, and the flattened root - with flattening of the crown in the same plane - makes this resemble sirenian tusks. 3 Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 Link to comment Share on other sites More sharing options...
siteseer Posted December 1, 2017 Author Share Posted December 1, 2017 5 hours ago, Harry Pristis said: Anything helpful here? dugongid_dentition.pdf Thanks for the paper, Harry. Jess 3 hours ago, doushantuo said: Thanks for posting the figure, Doushnatuo. Jess Link to comment Share on other sites More sharing options...
siteseer Posted December 1, 2017 Author Share Posted December 1, 2017 1 hour ago, Boesse said: This looks dugongid to me, and the flattened root - with flattening of the crown in the same plane - makes this resemble sirenian tusks. Thanks for taking a look, Bobby. There's a shot of sirenian fossils on page 20 of the mainstream guide, "Manatees and Dugongs of the World" by Jeff Ripple. It's a photo of a fossil dugong molar and tusk plus a manatee tooth. The specimens are not identified to genus nor are the localities noted. The tusk appears rather large - roughly 3 inches long and maybe 1 3/4 - 2 inches wide. Maybe you recall the photo. The tusk does not look like the same form figured by Domning. Do the tusks differ that much from genus to genus? I would assume some variation even within a species (some tusks longer; some more robust) but the tusk shown looks more probiscidean to me. Jess Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 maybe,given the specific use of sirenian tusks,there might be distinctive attrition ("dental wear")patterns. meanwhile edit: before i forget: recommended,althought the taxonomy might be obsolete Outtake: edit two: And also available in Fruitbat's library,I belatedly noticed(AFTER i posted this). As always kudo's to Joe Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 also recommended: Link to comment Share on other sites More sharing options...
doushantuo Posted December 1, 2017 Share Posted December 1, 2017 Link to comment Share on other sites More sharing options...
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