Cave bears

You thought there was only one cave bear species? You were wrong!

First, a big shout-out to for helping me with this, giving me all the info to get these bears as accurate as I could, discussing their colouration and even for coming up with common names. Thanks a lot dude!



 Ursus dolinensis - Trinchera Dolina cave bear

The most basal of all cave bears known from fragmentary remains from Sierra de Atapuerca, Spain. It lived from 900 000 to 780 000 years ago and had a size smaller than a black bear and had a more slender build than later cave bears, being more comparable to brown bears which isn't suprising when you know cave bears and brown bears split from a common ancestor 1.5 to 1 million years ago.


 Ursus savini nordostensis - Beringian cave bear

A basal cave bear from North Eastern Siberia, making it the most north-eastern cave bear known. It’s older than U. dolinensis, living 1.5 to 0.5 million years ago. The size of this bear was somewhere between that of the modern black bear and the modern brown bear.
U. s. nordostensis wasn’t a direct ancestor to more derived cave bears, but it likely was comparable to them only having less developed traits and being more gracile. Craniodental morphology suggests it was well-adapted to grazing. It also lived in hilly, mosaic landscape.

 Ursus savini rossicus - Small cave bear

These bears are really small, about as big as a black bear, and are known from the Ural and Altai Mountains. Their remains are carbon dated at 39.1 to 28.9 thousand years ago. First thought to be closely related to Ursus ingrussus  it turned out they actually are a subspecies of Ursus savini. 

 Ursus deningeri - Deninger's cave bear

Ancestral to all later cave bears is Ursus deningeri. It lived between 1.8 million and 100 000 years ago and was as big as a modern brown bear. The skull was already becoming proportionally larger and steeper, but not as pronounced as in its descendants.

A subspecies of this bear lived in the Caucasus region and Siberia, called U. d. kudarensis. They lived later, 560 000 to 37 000 years ago, and were as large as Ursus spelaeus spelaeus, the animal we all think of with the term “cave bear”.


 Ursus kavinetz ingressus - Gamssulzen cave bear

DNA evidence suggest U. k. ingressus diverged from U. spelaeus something of 400 000 to 170 000 years ago. These giant bears lived originally in Eastern Europe, remains show, but at about 32 000 B.C. a westward migration happened causing them to enter the parts of Europe where the classical cave bears lived. 23 780 years ago, when the latter went extinct, they were the only remaining cave bears left.
U. k. ingressus were huge! The biggest cave bears actually: at more than 130 cm tall at the shoulders and a weight coming close to 600 kg for the largest males, they're bigger than a Kodiak bear. Just like all later cave bears they were more robustly build than a normal bear, with proportionally bigger, steeper skulls. Special about U. k. ingressus is that isotope analysis from Romanian specimens showed their diet was different from other cave bears, which means they were or more omnivorous or ate a different source of plant food.
First considered to be  a species on its own (Ursus ingressus) a new study suggests it's a junior synonym of U. kavinetz which gave it the current name.

 Ursus spelaeus spelaeus - Classical cave bear

This is the cave bear you all know and have grown up with. They are your traditional, large headed, huge Ice Age bears. With a shoulder height of about 130 cm and a weight of 400 to 500 kg they are just a tad smaller than U. ingressus, but apart from this and their diet there isn’t much difference.
Like is probably known by most is that U. spelaeus were fully herbivore, rivaling even giant pandas at it. Of course the level of herbivory differed a bit from individual to individual and location. Although it was thought they went extinct about 28 000 years ago and got replaced by U. ingressus, there is fossil evidence from Rochenade, France, that they were still around here until 23 900 years ago. The immigration of U. ingressus and this species replacing them was probably more complicated than first thought.

A subspecies called U. s. eremus, was smaller than the classical cave bear and lived in higher latitudes, namely those of the Austrian Alps, Italian Alps and the Altai Mountains. They coexisted with U. ingressus for about 15 000 years: from 50 000 to 30 000 B.C. We know they aren’t the same species, because no gene flow is recorded between the two. What’s also interesting is that U. ingressus didn’t shrink as much in size up in the Alps in contrary to U. s. eremus, which could be explained by the different diet making U. ingressus more adaptable and eventually replacing all U. spelaeus subspecies at the very end of the Pleistocene.

And finally there was also a subspecies called U. s. ladinicus, the smallest of the trio. Remains of this small bear were found in the Dolomites, Northern Italy. They lived there from 60 000 to 30 000 years ago. How these almost fully herbivores were able to live in this Alpine environment could be explained that the Alps simply were warmer during this part of the Late Pleistocene allowing these animals to survive there. 
The size of U. s. ladinicus and U. s. eremus are a bit iffy, because I had to go from comparing their skulls with that of a subadult U ingressus. I might be a little off here...




A little note about the bears' sizes: The ones drawn are all males. Just like in today's bears they were sexually dimorphic, but the size difference in cave bears was even bigger so females would look quit small if they were in this chart. 

Size comparisons are made with Ursus arctos, the European brown bear, one Homo sapiens with lower quality and my hamster who passed away yesterday.


UPDATE 05-03-18:
U. rossicus turned into U. savini rossicus. I should redraw it because its colouration doesn't really seem to fit anymore looking at its relation to U. s. nordostensis.
U. ingressus is now considered a junior synonym of U. kavinetz which results in U. kavinetz ingressus.