Arctodus pristinus Miragaia longicollum Approximate measurements of the Sphenacodon:

Approximate measurements of the Sphenacodon:

which measured around 30 centimeters

Medidas aproximadas del Thalassodromeus :

ready to fight for its life

with extensive grasslands and scattered forests

Arctodus pristinus Miragaia longicollum Approximate measurements of the Sphenacodon:Arctodus pristinus is an extinct species of short faced bear belonging to the genus Arctodus , which lived in North America during the Pleistocene, approximately between 2. 5 million and 10,000 years ago. It was a close relative of Arctodus simus , although smaller in size and with some morphological differences in its skeleton that suggest different ecological adaptations. Its fossil remains have been found mainly in the southeastern United States,