“I” is for Ictidopappus
Ictidopappus is known only from one locality, the Torrejonian-aged Gidley Quarry in the Crazy Mountains Basin of Montana. At best it’s known from only one individual.
It’s certainly not found in The Breaks.
So why include it here?
Ictidopappus is one of the few Paleocene mammalian carnivores that are known. It’s in a Family called the Vivveravide, which went extinct in the Eocene. While clearly carnivores (based upon their tooth morphology), they do not appear to be related to the modern mammalian Order Carnivora.
Viverravus (above) is a typical member of the Vivveravidae. The overall shape of the back portion of the jaw, and the structure of the molars are what gives this away as a carnivore.
Carnivores tend to be rare in the fossil record. This makes sense. Consider lions and antelope on the Kalahari. There are always way more antelope than lions. Thus, it is more likely that antelope remains will be preserved than lion remains. The same relationship holds true in the fossil record. Any time a fossil mammalian carnivore is collected, it’s important.
Only four specimens that are clearly carnivorans (in this case the genus Protictis) are known from The Breaks. That’s four teeth, out of about 800 that were identified to the species level!
Part of the Blogging from A to Z challenge.