Two extinct predators had a thing in common apart from, well, being defunct. Scientists have found that the sea bear's (Kolponomos) powerful bite was similar to that of the saber-toothed cat (Smilodon).

Despite having different habitat and food preferences, the research team at the American Museum of Natural History (AMNH) has found that the two predators had the same jaw structure.

Based on high-resolution X-ray images and digital bite simulations, the two predators are more alike than previously thought.

"Both of them have a distinctive profile with a deep jaw bone that tapers off toward the back," said one of the researchers, Z. Jack Tseng.

Tseng said their team didn't expect that the Smilodon would be linked into the study of a clam-eating extinct predator but that's what they ended up with. The discovery was published in the journal Proceedings of the Royal Society B.

The two predators also shared the same extension on the back surface of the skull as well as the mastoid processes. This evidence suggests the presence of massive attachment areas, which allows the extinct animals to move their heads in a powerful but controlled motion.

Very few Kolponomos skulls and teeth fossils were discovered from ancient marine sediments in Oregon's Pacific coast and in Alaska. With very little fossils to work with, the sea bears remain a mystery in the animal kingdom's evolutionary tree.

Ancient sea bears were first described way back in the 1960s. However, they were first thought to be prehistoric relatives of the raccoon.

Succeeding studies of the fossil skulls suggested it might be related to the seal and eventually a bear. Research on its teeth fossil also revealed similarities on the shape and tooth wear of those in sea otters that use them to crush their hard-shelled prey.

The research team at the AMNH used CT scans to identify the bite style of the sea bears in comparison to those of the saber-toothed cat, river and sea otters, grey wolf, leopard and brown bear. The sea bear and the saber-toothed cat were found to have shared the closest jaw similarities.

Tseng added that the chewing bites of the sea bears and sea otters were not the same and the previously documented tooth wear was probably the result of overlapping diets. However, the evolutionary solutions at play to help them feed on hard-shelled preys were very much different.