Probably, the cause of death of cave bears (Ursus spelaeus) was too large sinuses, write in Science Advances. With them, the device of the skull was such that did not allow animals to eat meat while on a strict plant-based diet they were not able to survive the harsh winters of the maximum of the last glaciation.
Cave bears got their name because their bones are very often found in caves. They lived in Eurasia 300000-24000 (for other estimates — 15000) years ago. For a long time, the main reason for the extinction of these animals are considered intensive hunting people on them. Recently, however, paleontologists have suggested that to kill a cave bear could run out of food. The remains of individuals of this species, which from 100,000 to 20,000 years, showthat during this period the cave bears were adapted to eating only plants. And the amount of plant biomass with the onset of the maximum of the last glaciation 24,000 years ago has declined substantially.
The question arises, prevented the cave bears to rebuild your diet to become omnivorous, like bears (which at that time already existed). He was tried to meet scientists from Austria, Spain and the USA, headed by Alejandro pérez-Ramos (Alejandro Pérez-Ramos) from Málaga University. They compared the structure of the skulls of the cave bears and the now existing species of bear: brown, white, Himalayan, Malay, of sloth, American black bear, great Panda, and spectacled bear.
With the help of computer tomography, the researchers made three-dimensional models of the skulls of these species and determined the bite force of each of the species provided that the animal opens its jaws by 12 degrees. Points of application of power considered, or upper canines, or the fourth upper premolars or upper first or second molars. Paleontologists have created two series of models of skulls — the sinuses without them.