ammonites
Sifrhippus grangeri Gingerich 1989 (odd-toed ungulate)

Mammalia - Perissodactyla

Alternative combinations: Arenahippus grangeri, Hyracotherium grangeri

Full reference: P. D. Gingerich. 1989. New earliest Wasatchian mammalian fauna from the Eocene of northwestern Wyoming: composition and diversity in a rarely sampled high-floodplain assemblage. University of Michigan Papers on Paleontology 28:1-97

Belongs to Sifrhippus according to R. Secord et al. 2012

Sister taxa: Sifrhippus sandrae, Arenahippus aemulor

Ecology: ground dwelling browser-grazer

Average measurements (in mm): m1 7.65 x 5.25, femur 138.3 x 13.7, fibula 119.2 x 4.1, humerus 99.0 x 11.3, radius 86.6 x 8.3, tibia 123.0 x 10.6, ulna 107.1 x 8.0

Estimated body mass: 6.06 kg based on femur length, humerus length, tibia length, and ulna length