Fossil Deer-like Ruminant Skull | Leptomeryx evansi | South Dakota

Leptomeryx evansi Oligocene Brule Formation White River Badlands Custer County, South Dakota   Specimen approx. size: 3.5" x 1.75" x 2.25" Stand not included.   Leptomeryx evansi is an extinct species of small artiodactyl (even-toed ungulate) that lived during the Eocene to early Oligocene epochs, approximately 40 to 30 million years ago, primarily in what is now North America. It belongs to the genus Leptomeryx, which is part of the family Leptomerycidae—a primitive and early offshoot of ruminant evolution.   Morphology Leptomeryx evansi was a diminutive, slender-limbed ungulate, about the size of a modern jackrabbit or small deer (roughly 5–10 kg in body mass). Its body was gracile, with long limbs adapted for swift, cursorial locomotion. Like other members of Leptomeryx, it had: Long metapodials (fused lower limb bones), indicating fast-running adaptations. Digitigrade posture, walking on its toes, much like modern deer. Small, simple cheek teeth, suggestive of a diet that inc