Harry Pristis Posted March 15, 2010 Share Posted March 15, 2010 Here are a couple of teeth, a lower and an upper, from a little-known equid horse from Florida. This is a Mio-Pliocene horse from around 4.5 Ma. You could find fossils of this horse in the Peace River! This horse is also known from similar-aged faunas from North Carolina, Texas, Oklahoma, and Kansas. What is the scientific name of the horse, and what is unique about it? You could win a Golden Kudo with a modicum of research! 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...
Pool Man Posted March 16, 2010 Share Posted March 16, 2010 I'd say Nannippus aztecus. This horse seems to be found in all those areas. The most unique feature on these teeth I think is the protocone on the upper molar.Most other horses have a loop instead of a closed circle. Dan Link to comment Share on other sites More sharing options...
TourmalineGuy Posted March 16, 2010 Share Posted March 16, 2010 How "little-known" do you mean? Those look a lot like nannippus molars, which is unique because of its small size... Link to comment Share on other sites More sharing options...
Harry Pristis Posted March 16, 2010 Author Share Posted March 16, 2010 Nannippus is a reasonable guess, but it's not Nannippus. 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...
worthy 55 Posted March 16, 2010 Share Posted March 16, 2010 (edited) I will try Pseudhipparion,P. simpsoni...and the unusal thing about this horse is their cheek teeth are rootless for the first years of it's life and as the crown of the teeth are worn away additional enamel and dentine are added at the root ends to keep the teeth at the same height. From the Fossil Vertebrates of Florida Edited by Richard C. Hulbert, Jr. Edited March 16, 2010 by worthy 55 It's my bone!!! Link to comment Share on other sites More sharing options...
TourmalineGuy Posted March 16, 2010 Share Posted March 16, 2010 Alright, so its a Hipparion horse, due to the isolated protocone. (From what I've gathered) I'm going to say Pseudohipparion (simpsoni?)(if someone already didn't beat me to the post again) Unsure of what is exactly unique about this horse...it is also, very small. Link to comment Share on other sites More sharing options...
TourmalineGuy Posted March 16, 2010 Share Posted March 16, 2010 Ahhh, foiled again, although at least I had an incomplete answer! Haha, I'll give up on this one. Link to comment Share on other sites More sharing options...
JohnJ Posted March 16, 2010 Share Posted March 16, 2010 More homework and no guarantees. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Harry Pristis Posted March 16, 2010 Author Share Posted March 16, 2010 (edited) I will try Pseudhipparion,P. simpsoni...and the unusal thing about this horse is their cheek teeth are rootless for the first years of it's life and as the crown of the teeth are worn away additional enamel and dentine are added at the root ends to keep the teeth at the same hight. From the Fossil Vertebrates of Florida Edited by Richard C. Hulbert, Jr. Bingo! A Golden Kudo to 'worthy 55'! You are the man! This the only equid horse to develop hypselodonty to any degree. According to Hulbert in THE FOSSIL VERTEBRATES OF FLORIDA, "Pseudhipparion simpsoni occurs in the Palmetto Fauna of the Bone Valley region [at about 4.5 Ma], and is also known from similar aged faunas from North Carolina, Texas, Oklahoma, and Kansas. P. simpsoni is the only known horse that began to evolve hypselodont teeth. "The cheek teeth of P. simpsoni are rootless for first few years of its life, and as the crown of its teeth are worn away, additional enamel and dentin are added at the root-end of the teeth, keeping [them] at the same height. This process finally stopped, roots were added, and the teeth eventually were like those of other equids. Due to structual limitations,the portion added to the base of the teeth cannot contain fossettes, so their presence or absence indicates the relative age of the individual. Several incisors of P. simsoni are known and are all rootless, suggesting that they are fully hypselodont." I don't have an indisputable example of a rootless tooth; but, here's an image of a senile upper tooth. Note the missing fossettes, then notice how long proportionally the tooth is to be from a senile individual. Thanks to all who participated! Edited March 16, 2010 by Harry Pristis 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...
siteseer Posted March 16, 2010 Share Posted March 16, 2010 Pseudhipparion is also one of a few hipparionine horse genera that survives into the Pliocene of North America. Link to comment Share on other sites More sharing options...
worthy 55 Posted March 16, 2010 Share Posted March 16, 2010 Thanks Harry, just glad I had the book to look it up with. It's my bone!!! Link to comment Share on other sites More sharing options...
Harry Pristis Posted March 18, 2010 Author Share Posted March 18, 2010 As an afterthought, I'm adding an explanation of "fossette" to the thread. 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...
Uncle Siphuncle Posted March 19, 2010 Share Posted March 19, 2010 Thanks for the expert tutelage, Harry. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Harry Pristis Posted March 19, 2010 Author Share Posted March 19, 2010 Post from another thread by 'TourmalineGuy' copied here for its usefulness in IDing this little horse. Well, Roddy, I'm impressed! The outline of the enamel walls is one of the most useful diagnostic efforts I have seen on the Forum. Tell us how you did it so it can be replicated by other subscribers. I think you may have a Pseudhipparion cheek tooth. The size is correct. Plus, it has a diagnostic feature of that little horse: a hypoconal fossette. Congratulations! Image by 'TourmalineGuy' modified to highlight the hypoconal fossette. 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...
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