This is a fossil jaw bone of&nbsp;<a href="https://www.smithsonianmag.com/science-nature/paleontologists-uncover-the-oldest-sabertoothed-predator-180979725/" class="on">Diegoaelurus vanvalkenburghae, a newly discovered, earliest-known sabertooth species</a>. This sabertooth lived approximately 42 million years ago in ancient San Diego, a warm environment covered in lush forests.

This picture depicts a reconstruction of what&nbsp;Diegoaelurus vanvalkenburghae&nbsp;would have looked like in its natural habitat.Despite its intimidating fangs, scientists estimate&nbsp;Diegoaelurus vanvalkenburghae&nbsp;to be the size of a modern bobcat. Like other sabertooths, scientists predict it possessed special feeding adaptations, such as being able to cut meat using its cheek teeth. It might have fed on primates and other mammals.

Paleontologist Ashley Poust, pictured above, examined the fossil jaw bone after finding it in the <a href="http://www.sdnhm.org">San Diego Natural History Museum</a> fossil library. Poust theorised about&nbsp;Diegoaelurus vanvalkenburghae's&nbsp;path to extinction. As a hypercarnivore,&nbsp;Diegoaelurus vanvalkenburghae&nbsp;might have a difficult time switching to other food sources when prey changed or disappeared.&nbsp;&nbsp;Poust and colleagues reported their findings in <a href="https://peerj.com/articles/13032/" class="on">PeerJ</a>.#sabertooth #fossil #scientificdiscovery #paleontologyImage source: San Diego Natural History Museum