What is "hypertragulidae"

Hypertragulidae is an extinct family of artiodactyl ungulates that lived in North America, Europe, and Asia from the Eocene until the Miocene, living 46.2—13.6 million years ago, existing for about 33 million years.

The Hypertragulidae are basal ruminants that resembled small deer or musk deer in life. However, neither deer, nor musk deer are considered to be closely related to the hypertragulids. Instead, the chevrotains are probably the closest living relatives to these ancient deer-like animals.