The "gravel beasts" of the Oligocene and Pliocene are a bit of a skip from our normal fare here. Now and again we drop into the mammal-centric era of the Quaternary Period. The animals we find there are truly unique and bizarre. Some of the most unique, of course, are the gravel beasts, or the Chalicotheria. In particular this week is going to center on a single genus within the family: Chalicotherium. There are three recognized species of the enormous herbivorous browsing perissodactyls (odd-toe ungulates): Chalicotherium goldfussi Kaup, 1833; Chalicotherium salinum Forster-Cooper 1922; and Chalicotherium brevirostris Colbert 1934. Discovered throughout all of Eurasia regularly during the 19th and early 20th centuries, the first fossil was described by Johann Jakob Kaup in 1833 and originated in Miocene beds strata of Germany. The most intriguing elements of Chalicotherium species are the amalgam of characteristics that are seen together in this extremely tall and weird fossil mammal. These characteristics include horse-like heads, stout hindlimbs, and sloth-like forelimbs.