• No results found

CAVE BEAR

In document Extinct Animals (Page 136-139)

Scientific name: Ursus spelaeus Scientific classification:

Phylum: Chordata

Cave Bear—The cave bear’s steep forehead is clearly visible in this picture. Much of the space inside the forehead is taken up by the structures that supported the nasal tissue. This probably gave the bear an excellent sense of smell. (Ross Piper)

Cave Bear—Our ancestors would have frequently encountered the cave bear as they sought refuge in caves. (Phil Miller)

Class: Mammalia Order: Carnivora Family: Ursidae

When did it become extinct? Although they disappeared from many areas of Eurasia as early as 20,000–30,000 years ago, the cave bear fi nally became extinct around 10,000 years ago.

Where did it live? Th e remains of the cave bear have been found throughout Europe, to Russia in the east, Spain in the south, and France in the northwest. Th ey may even have reached Britain.

Of all the animals that have become extinct during the last 10,000 years or so, the remains of the cave bear are among the most numerous. In Dragon’s Cave, near Mixnitz in Austria, the remains of around 50,000 cave bears have been found. Indeed, almost every cave in central Eu-rope with an entrance big enough to permit the entry of a large animal will have, at some point, played host to this extinct bear. Suitable caves were used by generation upon generation of these bears over hundreds of thousands of years, and where the passages are quite narrow, the walls have been polished by the comings and goings of countless furry bodies over the ages.

Superfi cially, the cave bear was very similar to the living brown bear, but it was undoubt-edly a distinct species. It was much bigger than a European brown bear ( Ursus arctos ), and some adult males, fat from feeding in preparation for the winter hibernation, probably weighed in the region of 400 kg. Th e cave bear also had a relatively large head and short, powerful limbs, while the brown bear has a leggier appearance. Th e most notable feature of the cave bear’s skeleton is its large, domed skull, which has a characteristically steep fore-head. Unfortunately for this extinct bear, this vaulted cranium did not house an enlarged brain. Cutting one of these ancient skulls in half shows that the braincase of the cave bear was no bigger than that of the brown bear, and much of the extra space is actually taken up by air spaces and all the elaborate structures that gave the cave bear a very acute sense of smell. Th e living bears are renowned for their keen sense of smell, but it seems the cave bear could probably outperform any bear, living or dead, in tracking scents.

As with the bones of the giant short-faced bear (see the entry on this animal in chapter 6), chemical analyses of the remains of the cave bear have revealed some interesting things about the life of this animal. Most living bears are opportunistic omnivores that eat what-ever, whenever they can fi nd it. Apparently, the cave bear was predominantly a herbivore that probably fueled its bulk with all manner of succulent leaves, bark, roots, tubers, fruits, nuts, and seeds. Although the teeth of the cave bear are undoubtedly those of a generalist, they have lost some of the carnivorous edge seen in the dentition of the living brown bear.

Its molars were absolutely massive, perfect for crushing and pulverizing tough plant foods.

Although the cave bear may have been very keen on plant food, it is very unlikely it turned its sensitive nose up at the chance of consuming meat when it was easily available such as from an abandoned carcass. Th ere are even bones from some localities that suggest that, at least in some places, the bears were mostly feeding on meat.

Because so many remains of the cave bear have been found over the years, we have a very good picture of what ailments these animals suff ered from. Th e skeletons of many cave bears show signs of osteoarthritis, and in severe cases, the vertebrae of the spine have fused together or elaborate outgrowths of bone have sprouted from the limbs. Severe cases of this disease made the suff ering animal lame. In many skeletons, there are the telltale signs of severe dental wear and disease, and in the sinuses of the heads of a few individuals, there are the large pockmarks of bone-eating bacterial infections. Although cave bears were robust animals, they broke their bones in falls and fi ghts, and in many cases, the bones were mis-aligned when they knitted back together, leaving the poor animal crippled, but apparently still able to survive. Some individuals also suff ered from rickets, a disease caused by a lack of vitamin D and which results in bone deformities such as bowed limbs. Bears, like hu-mans, synthesize vitamin D in their skin in the presence of sunlight, and as cave bears were forced to see out the harsh winter by hibernating in rocky refuges, they often didn’t produce enough vitamin D. Rickets was particularly common in bears living at high altitudes due to the short ice age summer season in the high mountains. Th ese high mountain bears were forced to spend more time in their caves than bears living at lower elevations. Perhaps the most bizarre affl iction is the injury sustained by some unfortunate male bears. All male bears, and many other male mammals, for that matter, have a bone in their penis called the baculum. In some male cave bears, this bone was broken, but exactly how it was fractured is a mystery. Was it broken when a mating male bear was fending off other potential suitors, or was it stepped on in a dark cave long after the bear died?

Th is extinct bear’s predilection for caves must have brought it into direct competition with prehistoric humans, who prized these places as refuges from the elements and preda-tors. Our Pleistocene ancestors defi nitely knew of the cave bear and even depicted it in various paintings, which can be seen in a number of caves throughout Europe. One very interesting painting shows a cave bear that seems to be bristling with spears, blood gush-ing from its mouth. Early cave bear fi nds suggested to some experts that our ancestors may have revered these animals. High up in the Swiss Alps, Drachenloch Cave was reported to contain what appeared to be the oldest stone structure of religious signifi cance anywhere in the world. Attributed to Neanderthals who lived 70,000 years ago, this case was the basis for the so-called Cave Bear Cult. One cave bear skull was even found with a cave bear femur twisted behind the cheekbone and was considered to be the work of human hands. Th e

famous paleontologist Björn Kurtén challenged this view and suggested that the peculiar arrangements of bones could have been produced by chance as other bears shoved old bones around the cave fl oor, preparing their winter retreat.

Th ese and other fi nds give us a fascinating glimpse of how early humans and long-dead animals interacted in a very diff erent world. Some cave bear bones have been found bearing the scorches from fi re and the cut marks from stone tools. Th ese show that prehistoric hu-mans hunted the cave bear. But did they drive it into extinction? Th e cave bear survived hun-dreds of thousands of years of oscillating climatic conditions and changing habitat, and in the very harsh glacial periods, the species may have been reduced to small populations that man-aged to cling to survival in sheltered valleys. Perhaps it was human hunting in combination with the pressure of a changing climate that led to the demise of these interesting mammals.

• During the age of discovery, when gentlemen scholars started to probe the prehistory of the earth, it was thought that the cave bear fell into two distinct groups: dwarves and giants. In actual fact, the diff erence in size of the cave bear skeletons was due to sexual dimorphism: adult male cave bears could weigh twice as much as females.

• In some caves, there are deep scratches in the walls, which were almost certainly left by the claws of a cave bear. Were they marking their bedding areas, or were they trapped in a rock fall? It is thought the former is more likely.

• A complete fl int weapon tip was found in a cave bear skull discovered near Brno in the Czech Republic, indicating that a human hunter was trying to kill the animal at very close quarters. Hunting a cave bear must have been a very dangerous business. Th ey may have been herbivorous, but they were immensely strong and probably very easily angered. A large, rearing cave bear was at least 3 m tall, and a swipe from one of its massive paws would have easily snapped the neck of a human assailant.

Further Reading: Kurten, B. The Cave Bear Story . New York: Columbia University Press, 1976.

In document Extinct Animals (Page 136-139)