アメリカ自然史博物館のインスタグラム(amnh) - 10月15日 05時41分

#NationalFossilDay Puzzle 6/6: The nose knows! A keen sense of smell in many mammals is made possible by a maze of thin, heavily folded bones called turbinates in the nasal and forehead cavities. Different divisions of turbinate bones function as sticky traps for chemical compounds (“smell”) or help to warm up the inhaled breath before it travels to the lungs. A large nasal opening on this skull and large space within the nasal cavity both indicate that this mammal could have had a lot of turbinate surface area to smell with. Have you guessed what this mammal is yet? Take a look at the AMNH Instagram feed in grid view to see!

Answer: this skull belongs to Amphicyon ingens, the largest land predator of its time--about the size of a large grizzly bear. Commonly known as bear-dogs, the family Amphicyonidae (in which Amphicyon belongs) is in the carnivoran group, which also includes bears and dogs. But paleontologists don’t agree on which of those animals it is closer to on the carnivoran tree of life. That’s a piece of the “puzzle” we still haven’t figured out. Happy National Fossil Day!

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