Hyracodon

Hyracodon ('hyrax tooth') is an extinct genus of perissodactyl mammal.

H. nebraskensis skull, found near Hermosa, South Dakota.

Hyracodon Temporal range: Middle Eocene–Late Oligocene PreꞒ Ꞓ O S D C P T J K Pg N
Skeleton in Natural History Museum of Los Angeles
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	†Hyracodontidae
Genus:	†Hyracodon Leidy, 1856[1]
Species
†H. browni †H. leidyanus †H. medius †H. nebraskensis †H. petersoni †H. affinis †H. eximus †H. modestus †H. primus †H. princeps †H. priscidens

It was a lightly built, pony-like mammal of about 1.5 m (5 ft) long. Hyracodon's skull was large in comparison to the rest of the body. Hyracodon's dentition resembled that of later rhinocerotoids, but it was a much smaller animal and differed very little in appearance from the primitive horses of which it was a contemporary (32–26 million years ago). It had a short, broad snout and its long, slender limbs had three digits.^[2]

Like the primitive horses, hyracodonts inhabited open forests and wooded steppes and turned from browsing foliage to grazing grass. They died out without leaving any descendants and they mark the end of the phylogenetic branch of hornless, running rhinocerotoids.

Illustrations

1896, Charles R. Knight

1913, Robert Bruce Horsfall

1920, Heinrich Harder