|The Academy of Natural Sciences in Philadelphia, PA
maintains the online
Thomas Jefferson Fossil Collection and a web page about
Dr. Joseph Leidy. He is
referred to as The Father of American Vertebrate Paleontology. You will find there a link to a page prepared in his honor called
Extinct Western Vertebrates (1873): Plate XXXIII
Dr. Leidy identified the four molars there as belonging to Equus occidentalis. I labelled a copy of his
image below left as "Dr. Leidy's Equus occidentalis".|
In 1996, I placed a number of teeth in my Hallquist collection.
Two molars have attached bone fragments. The teeth are still partially in original sockets. The two specimens fit together as shown on the right below. They are 6 cm long. Four separate upper molars are in the collection. I bound them together with elastic bands, to compare them with Dr. Leidy's set. Interestingly, these four teeth together with the two just mentioned appear to be a complete set of six. I used information on the Anatomy page of the Equine Dentistry site to label the set as premolars pm2, pm3, pm4 and molars M1, M2, M3. I also learned from that site that the teeth are from a left side upper cheekbone.
You see above three image versions pm2, pm3, pm4, and M1. How do you think they compare with
E. occidentalis? Premolar pm2 is more worn than the specimen used as a model for Dr. Leidy's
leftmost tooth. My molar M1 shows a pit due to mechanical damage or decay.|
I used an Intel Create and Share PCI camera. I believe much better images would have been obtained if I had used my Olympus OM-1 35 mm film camera and a macrobellows arrangement.