DailyMail They were bear-sized creatures that prowled the coastline of the north west United States around 20 million years ago gobbling up shellfish on the shore. But a giant otter-like animal, which is thought to be a distant relative of modern bears, appears to have had a far more formidable bite than had been expected. Researchers have discovered the extinct Kolponomos had a jaw that worked in a similar way to another very different kind of carnivore – the sabre toothed cat Smilodon. But while sabre-toothed cats are thought to have used their powerful lower jaws as anchors to thrust their knife-shaped teeth into flesh, Kolponomos did not have similar teeth. Instead scientists now believe the animal, which is often nicknamed the ‘marine bear’, may have used its jaws to pry lose food from rocks along the shore. Using computer models of the animal’s jaw, researchers have been able to reconstruct how they think it may have fed. Placing its lower jaw as an anchor against the shellfish on the rock, it would have then thrown its skull forward forcefully to pry its stubborn prey loose. Dr Jack Tseng, a fellow at the American Museum of Natural History who was the lead researcher on the study, said: ‘I started seeing a great deal of similarity between the jaws of Kolponomos and Smilodon. ‘Both of them have a distinctive profile with a deep jaw bone that tapers off toward the back, and both have an expansion of the mastoid processes and the skull’s back surface, suggesting large attachment sites for muscles that let the animal move its head powerfully but with control. ‘We definitely didn’t expect to bring Smilodon into this study of feeding in a clam-eating marine carnivore, but that’s what we ended up doing.’ Kolponomos is only known from a handful of fossils – mainly skulls and teeth from two species, found in ancient marine deposits along the Pacific coast of Oregon, Washington and Alaska. The ancient predators are thought to have been around the size of a small bear, growing to be 4ft-long (1.2 metres) and 2.2ft-tall (0.6 metres), while weighing around 180lbs (82kg). It was first discovered in the 1960s when palaeontologists believed it may be a relative of the raccoon. Later research suggested it may be more similar to a seal or a bear. However, wear on the teeth has also been found to be similar to sea otters, which use their powerful jaws to pry open shellfish and eat the soft meat inside. The researchers, whose work is published in the journal Proceedings of the Royal Society B, initially set out to examine whether Kolponomos crushed shells in a similar way to otters when eating. However, the predator appears to have had a very different approach to tackling its food. Dr Tseng said: ‘Our biomechanical data show that the chewing bites of sea otters and Kolponomos are not very similar. ‘They probably still have an overlapping diet based on tooth wear, but their evolutionary solutions for getting to those hard-shelled animals are dramatically different.’ Dr Tseng and his colleagues used computed tomography scans of the skulls of Kolponomos and compared them to six other canivores – smilodon, grey wolves, sea otters, river otters, brown bears and leopards. The scans were used to build sophisticated biomechanimcal models of each animal to look at how they might have performed various bites. The work suggests Kolponomos may have pried shellfish off rocks with its lower jaw, swung its skull forward to dislodge it before crushing the shell as it chewed.
In this blogger’s opinion, the coolest time in the history of earth was post-dinosaurs, when early mammals ruled the planet’s dry land. Some of these creatures evolved into animals that still exist today, some were giant relatives of mammals that exist today, and some went extinct and ceased to exist entirely leaving behind small bone fragments as part of the fossil record. Today I came across this article about an amazing prehistoric creature called Kolponomos, a which is an early ancestor of modern bears and otters, that scavenged the prehistoric coastlines eating shellfish and scavenging on whatever else washed up from the prehistoric seas. Kolponomos was the size of a small modern-day bear used it’s extremely powerful jaws to crush prehistoric seashells to get to the meat inside. Bears, seals, otters and raccoons are all believed to have a common ancestor at some point deep in prehistory, and while Kolponomos may not be the link, it is an amazing branch on the evolutionary family tree.