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+---- Thread: Bears of the Pleistocene (/topic-bears-of-the-pleistocene)
RE: Bears of the Pleistocene - brotherbear - 08-12-2016
Any information about the claws and teeth of Arctodus simus? I'm sure that his claws were not designed for climbing trees. Was he a digger like the grizzly or perhaps his claws were simply dog-like for walking and running. What length canine teeth and claws?
RE: Bears of the Pleistocene - GrizzlyClaws - 08-12-2016
(08-12-2016, 02:03 AM)brotherbear Wrote: Any information about the claws and teeth of Arctodus simus? I'm sure that his claws were not designed for climbing trees. Was he a digger like the grizzly or perhaps his claws were simply dog-like for walking and running. What length canine teeth and claws?
Polar bear canine = 5 inches max
Brown bear canine = 4.5 inches max
Cave bear canine = 6 inches max
Short faced bear canine = 6 inches max???
RE: Bears of the Pleistocene - brotherbear - 08-12-2016
Thank you GrizzlyClaws. I did find this, but of course with just one tooth five inches long we can only say that their canines could have been at least this long.
https://boneclones.com/product/short-faced-bear-canine-teeth-single-KO-115S
*This image is copyright of its original author
RE: Bears of the Pleistocene - brotherbear - 08-12-2016
https://www.jstor.org/stable/20627694?seq=1#page_scan_tab_contents
Fossils of the giant short-faced bear, Arctodus simus (Cope, 1879), have been recovered from over 100 localities in North America, extending from Mexico to Alaska and California to Virginia. Despite this large range, the species has never been recorded from the southeastern United States. The lesser short-faced bear, Arctodus pristinus Leidy, 1854 is well represented from this region, particularly Florida, but all known occurrences are late Pliocene — middle Pleistocene in age (about 2.5 to 0.3 Ma). Differentiating A. simus from A. pristinus can be difficult because large individuals of A. pristinus overlap in size with small individuals of A. simus, and there are few morphological differences. However, these two taxa can be clearly separated based on the relative proportions of their molars and premolars. Two Pleistocene records of A. simus representing a minimum of three individuals from the Withlacoochee River drainage of central Florida are reported here, substantially extending the distribution of this massive bear into southeastern North America. A late Pleistocene age for these occurrences is corroborated by an associated Rancholabrean fauna and rare earth elemental analyses. One of the reported individuals is quite large, supporting the hypothesis of extreme sexual dimorphism in A. simus and rejecting a hypothesis of two subspecies.
RE: Bears of the Pleistocene - GrizzlyClaws - 08-12-2016
Based on a holotype skull of the Ussuri Brown bear, its canines are 4 inches from a 16 inches skull.
Since the Cave bear got the similar proportional canine teeth with the Brown bear, then I assume the largest Cave bear skull (24 inches as a record) should have 6 inches canine teeth.
RE: Bears of the Pleistocene - GrizzlyClaws - 08-13-2016
4 inches brown bear canines
*This image is copyright of its original author
RE: Bears of the Pleistocene - brotherbear - 08-13-2016
This bear "Indarctos" predates the Pleistocene: https://en.wikipedia.org/wiki/Indarctos
Body mass
Two specimens were examined by Legendre and Roth for body mass.
- Specimen 1 estimated to weigh: 244 kg
- Specimen 2 estimated to weigh: 2517 kg
2517 kg = 5,549 pounds. Is this a typo?
RE: Bears of the Pleistocene - tigerluver - 08-13-2016
Here's the paper cited in that article. I don't see any mention of Indarctos but I just skimmed the paper so maybe I missed it.
RE: Bears of the Pleistocene - brotherbear - 08-27-2016
http://www.dailymail.co.uk/sciencetech/article-3759796/Can-vegan-make-EXTINCT-Picky-prehistoric-cave-bear-s-diet-caused-die-out.html
Weighing more than half a ton and equipped with huge teeth capable of crushing bones, the prehistoric cave bear would seem equipped to be a top Ice Age predator.
But new research suggests these enormous bears may actually have been absurdly picky eaters that survived on a largely vegan diet.
The findings provide new clues for what led these beasts to die out around 25,000 years ago during the last glacial period.
While most modern bears are omnivorous, consuming everything from tiny berries to fish and deer, analysis of bones from extinct cave bears has revealed that they stuck to a strictly plant-based diet.
Using cave bear bones found at the Goyet Cave in Belgium, a team of international researchers managed to reconstruct the bears' diet.
Specifically, they looked at the isotope composition of collagen in the bones.
Collagen - a protein that makes up the scaffolding of most tissues including bones, teeth, tendons and skin - is made up of amino acids that vary according to an animal's diet.
The analysis eventually revealed cave bears lived on subsisted on a rigidly vegan diet.
Even bear cubs that had been suckling milk showed a vegan-like collagen make-up due to their mother's dietary regime.
'Similar to today's giant panda, the cave bears were therefore extremely inflexible in regard to their food,' said lead researcher Professor Hervé Bocherens, from the Senckenberg Center for Human Evolution and Palaeoenvironment at the University of Tübingen in Germany.
'We assume that this unbalanced diet, in combination with the reduced supply of plants during the last ice age, ultimately led to the cave bear's extinction.'
Cave bears first appeared in Europe around 400,000 years ago. Measuring up to 11 feet (3.5m) long and 5.5 feet tall at the shoulder (1.7m) they were formidable animals.
They earned their name as many remains of these beasts have been found in caves.
However, they are only thought to have hibernated in caverns and spent most of their time roaming searching for food.
'We believe that the reliance on a purely vegan diet was a crucial reason for the cave bear's extinction,' Professor Bocherens added, whose work is published in the Journal of Quaternary Science.
The team is now hoping to study cave bear bones from other areas in order to confirm their hypothesis.
'We now intend to examine additional cave bear bones from various European locations with this new method, as well as conducting controlled feeding experiments with modern bears, in order to further solidify our proposition,' Professor Bocherens explained.
RE: Bears of the Pleistocene - tigerluver - 08-27-2016
(07-21-2016, 11:47 PM)brotherbear Wrote: Tigerluver; Your post on four of the biggest bears ever ( post #53 ) is really outstanding. I'd love to see a modern polar bear, Florida cave bear, European cave bear, and Agriotherium africanus... if possible. Thank you.
I'm working in this request by first looking at bone data myself.
Here's a humerus of the Florida cave bear I've found (about 400 mm based on the scale bar):
*This image is copyright of its original author
Source
Kurten has a few volumes dedicated to fossil bears. Unfortunately, I can't find a location to get my hands on such.
RE: Bears of the Pleistocene - brotherbear - 08-30-2016
Bones are sometimes fossilized and teeth are often well preserved. But, what about claws? The shape and size and other specifics about claws could provide evidence as to the habbits of a bear species. Are there any well preserved ancient bear claws to be found?
RE: Bears of the Pleistocene - GrizzlyClaws - 08-31-2016
I've seen some Cave bear claws, and they weren't as impressive as the modern grizzly's.
RE: Bears of the Pleistocene - brotherbear - 08-31-2016
(08-31-2016, 02:13 AM)GrizzlyClaws Wrote: I've seen some Cave bear claws, and they weren't as impressive as the modern grizzly's.
Yes, post #81 describes the claws of a cave bear as being shorter than those of a grizzly but very stout, probably used for digging. I would agree with the digging theory as cave drawings portray the cave bear with a huge shoulder hump similar to that of a grizzly. But, while I know that short-faced bear remains have been found in the La Brea tar pits, I have yet to read any description of their claws. Just curious.
RE: Bears of the Pleistocene - GrizzlyClaws - 08-31-2016
Although the Cave bear species is closely related to the Brown bear, but still a different species nevertheless, so we cannot really generalize them with the Brown bear.
As for the Short Faced bear, they were built as the runner, so those long claws are definitely not suitable for sprinting.
RE: Bears of the Pleistocene - brotherbear - 09-02-2016
These Irish grizzlies survived the Pleistocene, but just barely: http://mysteriousuniverse.org/2016/03/fossils-shed-new-light-on-what-or-who-killed-the-irish-bears/
Fossils Shed New Light on What or Who Killed the Irish Bears