19 April 2016
The closest living relatives to our giant predator is a giant herbivore. This has happened many times in the history of life and as such it is not remarkable in terms of being a revelation. However, Andrewsarchus is actually considered the sister taxon to whales and small mammals known as Raoellidae (Geisler and Theodor 2009). Spaudling, O'Leary, and Gatesy (2009) were slightly less confident with the single skull but upheld the close relationship with whales and hippos. Instead of asserting a solid relationship at a single node, Andrewsarchus is placed in a polytomy with a small group of other fossil taxa. Ignoring phylogenetics and discussions of sister groups, the initial description by Osborn is online. I always urge people to read initial descriptions and that initial description is hosted right here.