20 April 2016
Superb Skull of A Gigantic Beast
The remain of Andrewsarchus consist of a single Mongolian skull from a presumed adult specimen. The skull is not a complete cranium and is lacking the mandible. This means that we do not know anything from solid evidence about the dentition of the lower jaw. The assumptions that are considered when looking at possible stand ins for the lower jaw include similarly built carnivores and members of Andrewsarchus' branches of the mammalian family tree. Simply put, this means that we have to consider whales, hippos, and small extinct mammals of the family Raoellidae. An assumption exists, regardless of the model taxon used to inform the mandible, that the teeth belonged to a strict carnivore. Contention in the field crew existed over this idea with Roy Chapman Andrews asserting that the 3 foot long skull belonged to a great predator and the chief paleontologist (Walter Granger) attributing the skull to a giant pig, essentially calling it an omnivorous beast of great size. No one disagreed on the great size, whatever their view of the diet. The known dentition is respectable and fearsome in the 3 foot skull. The dental formula is 3 incisors, 1 canine, 4 premolars, and 3 molars. This is the exact dental formula of extant pigs. That explains Granger's suspicions of the phylogenetic position of Andrewsarchus. Hippos have the same formula, with some variation, which backs up Chapman's assertions. Recent evidence has also reinforced Chapman's position rather than Granger's, but we cannot argue that he had a valid reason for being suspicious of the origin of the beast we know as Andrewsarchus.