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Bears of the Pleistocene
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Body mass estimation On The steppe brown bear (Ursus arctos Priscus) From Marcizak et al. 2019; It seems to suggest that Ursus priscus overlapped with The short faced bears (arctodus simus & Arctotherium angustidens) In weight.
 *This image is copyright of its original author
Middle Pleistocene genome calibrates a revised evolutionary history of extinct cave bears
Summary: Palaeogenomes provide the potential to study evolutionary processes in real time, but this potential is limited by our ability to recover genetic data over extended timescales.1 As a consequence, most studies so far have focused on samples of Late Pleistocene or Holocene age, which covers only a small part of the history of many clades and species. Here, we report the recovery of a low coverage palaeogenome from the petrous bone of a ∼360,000 year old cave bear from Kudaro 1 cave in the Caucasus Mountains. Analysis of this genome alongside those of several Late Pleistocene cave bears reveals widespread mito-nuclear discordance in this group. Using the time interval between Middle and Late Pleistocene cave bear genomes, we directly estimate ursid nuclear and mitochondrial substitution rates to calibrate their respective phylogenies. This reveals post-divergence mitochondrial transfer as the dominant factor explaining their mito-nuclear discordance. Interestingly, these transfer events were not accompanied by large-scale nuclear introgression. However, we do detect additional instances of nuclear admixture among other cave bear lineages, and between cave bears and brown bears, which are not associated with mitochondrial exchange. Genomic data obtained from the Middle Pleistocene cave bear petrous bone has thus facilitated a revised evolutionary history of this extinct megafaunal group. Moreover, it suggests that petrous bones may provide a means of extending both the magnitude and time depth of palaeogenome retrieval over substantial portions of the evolutionary histories of many mammalian clades. 
Velizar Simeonovski
Some big bears: Cave bear ( Ursus spelaeus ) (top) Short-faced bear ( Arctodus simus ) (middle) "African bear" Agriotherium africanum (bottom)  *This image is copyright of its original author Note the cave bear but it's another African extinct bear specy , the Atlas bear , this skull was discovered in Algeria , the last recorded sight of that bears was in 1950  *This image is copyright of its original author  *This image is copyright of its original author
Cave bear predation
"Leopards must have followed, similar as known for larger felids steppe lions (cf. Diedrich, 2012, 2013e) the cave bear scavenging (or cub hunt) in mountain, and especially alpine regions even far deep in caves (Baumann’s Cave, Wildkirchli Cave, Vjetrenica Cave, Zoolithen Cave). This predation stress by two large nocturnal best climbing felids (lion/leopard) are the main reason, why cave bears hibernated as deep as possible in large cave systems to protect themselves and their cubs (Diedrich, 2012; 2013e;Fig. 14). The fossil ratio in European cave bear den caves between leopards and lions is nearly 100 lion/1 leopard bones, which demonstrate much less predation/scavenging stress onto cave bears by leopards. (Fig. 15)" (PDF) Late Pleistocene leopards across Europe - northernmost European German population, highest elevated records in the Swiss Alps, complete skeletons in the Bosnia Herzegowina Dinarids and comparison to the Ice Age cave art (researchgate.net)
Ice Age Cave Bear With Hole in Its Skull May Have Been Stabbed by Ancient Humans
Cave bears were hulking beasts you wouldn’t want to run into in the dark (even if they were mostly vegetarians). But it seems a human got the better of one of these now-extinct ursids, according to an assessment made by Russian paleontologists last month. The team revealed cave bear remains found in the Imanay Cave in the Southern Ural mountains. The cave is chock full of thousands of bone fragments, including remains of red foxes, mammoths, cave lions, marmots, woolly rhinos, and steppe bison. Among the bones was the skull of a small cave bear, Ursus rossicus. Based on a narrow, oblong hole found in the animal’s skull, the team determined the ancient bear was likely killed by a human, as discussed in a paper describing the find recently published in Vestnik Archeologii, Anthropologii I Ethnographii. “The hole in the skull could be either natural or artificial,” said Dmitry Gimranov, senior researcher at the Ural Branch of the Russian Academy of Sciences and the Ural Federal University, in a university press release. “In the first case, for example, a stone could fall on the bear’s head, or water dripped onto the skull during thousands of years. But this is highly unlikely. Most likely the animal was killed by ancient people.” Gimranov and his colleagues dated the bear skull to about 35,000 years old, and, based on growth layers in the animal’s teeth, deduced that it was about 10 years old when it died. The skull was found near evidence of Pleistocene human habitation and comes after three years of excavations in the cave, which sits in Bashkiria National Park. Paleontologists have known that Pleistocene humans relied on large mammals for food, including woolly mammoths, and some cave bear bones have shown evidence of meat removal. But this is the first direct evidence of a bear being hunted, according to the team. It’s not the first time an Ice Age cold case has turned up. In 2019, a saber-toothed cat cranium with a hole in skullcap led researchers to believe the big cats may have fought amongst their own species. Though not a murder mystery, last summer a cave bear came out of the Siberian permafrost so well preserved that its toothy grin could be seen on a head still covered in muscle tissue and fur. No arrowhead or spearpoint was found in the recently excavated bear skull, but the researchers determined that the hole was more likely made by a human weapon than by natural deterioration. Layers of the cave that included human-made materials contained a sharp flint biface, for example, which could have been used to stab the animal. “A hole in the skull could have been made after the death of the bear as a ritual practice,” Gimranov said, adding that evidence of bear hunting from this period is “extremely rare.” Perhaps most intriguingly, this dead bear showed no evidence of hack marks or other traces that would suggest its meat had been removed for consumption. So why poke a hole in it? As Gimranov noted, it may have been a ritual stabbing. Maybe humans walked into the cave after a long day out on the ice and stumbled upon a hibernating bear. While the case might never be solved, it’s a fascinating glimpse into another epoch.  
Cave Bear skeleton
Credit to Daniel Loke  *This image is copyright of its original author
Cave Bear in American Museum of Natural History
Photo by D. Finnin  *This image is copyright of its original author  *This image is copyright of its original author
Palaeoecological and genetic analyses of Late Pleistocene bears in Asiatic Russia
Abstract: Brown bears are one of the few large carnivore species that survived the final Pleistocene wave of extinctions, perhaps in part owing to their wide ecological plasticity, variety of forms and polyphagia. Although the brown bear has become a well-studied system, many questions remain regarding the ecological, trophic and genetic diversity throughout their distribution. For example, knowledge about Asiatic Russian brown bears from the Late Pleistocene arctic tundra steppe, an ecosystem with no analogue in modern times, is sparse. Here we compared diets, morphometry and genetic affinities of Late Pleistocene bears based on broadly sampled subfossil remains from Asiatic Russia. Collecting sites included the Ural Mountains, the lower reaches of the Irtysh River, the upper reaches of the Ob River, the Altai Mountains of western Siberia, the Indigirka–Kolyma Lowlands and northwestern Chukotka. An extremely large bear specimen from the middle Indigirka (41 090 14C a BP) that lived in landscapes of treeless shrubs and wet meadows had a diet composed principally of large herbivorous mammals. A bear from western Chukotka (25 880 14C a BP), much smaller in size, had a diet close to that of modern brown bears. These two Late Pleistocene NE Russian brown bears may comprise a previously undiscovered, but extinct, genetic lineage. At the end of the Pleistocene (MIS 3 and MIS 2), the brown bears from the Ob River Valley and Urals lived in periglacial forest-steppes and those from the southern Urals in conditions of periglacial steppe. Brown bears from the Ob River valley and Urals, as well as ancient Altai bears, were characterized by avaried diet, from polyphagia to vegetarianism. In living brown bears, the proportions of different dietary foods are primarily related to food availability, which depends on the geographical zone and climatic conditions. We conclude that the same was true for Late Pleistocene brown bears of NE Siberia 
I read that in the Pleistocene, the cave bear limited the distribution of the brown bear, and that it became widespread after the cave bear became extinct. This is true?
After all, the Pleistocene steppe brown bear was even larger than the cave bear + they have different niches. The steppe bear was more predatory than the modern brown bear, which in turn is more predatory than the almost completely herbivorous cave bear. So they have different niches. How could a cave bear "keep out" a brown one? In addition to the huge U. a. priscus in the Late Pleistocene was inhabited by almost the same huge U. a. kamiensis. About the first they write that the average weight was from 700 to 1000 kg. Is this true or an exaggeration? If so, this is the average weight of the arctodus, and is more than the polar bear, the kodiak bear, and the cave bear, whose average weight was about 500 kg.
Hi.
Ursus arctos priscus was really a huge bear and it is probably not an exaggeration. I am european and i am in contact with professional paleontologists. This year, it is possible that some new materials will be available about giant prehistoric brown bears in Europe. According to my contact some bones suggest skulls between 550 mm and 650mm, if this is confirmed it is absolutely gigantic. Without limb bones it is difficult to evaluate the mass of an animal. But no doubt that this bear were among the largest and the most powerful carnivores in Europe. Some cave bears were not entirely herbivorous. Skulls around between 500 mm and 550 mm are in fact not exceptional, we have a skull which is 571 mm in length and a european paleontologist have personally measured a skull which is 600 mm in length, almost the length of the skull of Megistotherium! So there were very large bears in Europe but a lot of material is not published.
Some prehistoric bears had really big mandibles. Here i would like to point out a huge mandible concerning Arctotherium Angustidens which is 395mm in length (specimen BMNH32916, first column of the Table)!
Source: First Record of Arctotherium (Ursidae, Tremarctinae) in Northwestern Argentina and its Paleobiogeographic Significance - 2008. According to you, what would be the length of the skull of this specimen? I don't know the ratio between skulls and mandibles in bears. But there is more surprising: look at the specimen MACN 851 in the second column. The length of the mandible is not specified but all others measurements seems larger than the one previously cited. So correct me if i am wrong but maybe we have a mandible of Arctotherium around 400mm??? Thanks for your responses.  (06-07-2023, 11:50 AM)hibernours Wrote: Hi. Can I see the link where someone found a 600 mm long bear skull? (07-02-2023, 10:33 AM)johnny rex Wrote:(06-07-2023, 11:50 AM)hibernours Wrote: Hi. Well, i will summarize you some measurements and data about prehistoric bear skulls (cave bears and brown bears) and answer to your question. Keep in mind that the longest skull is not necessarily the largest skull because we must take into account the width and the height of a skull in order to determine its volume. So: 1. Cave bears had proportionally larger head relative to body size than brown bears. The longest skull (not necessarily the largest in term of volume) that i know from recent source was 571,4 mm in length. Source: Fossil findings of cave bears from the upper Pleistocene sediments of selected caves in Slovakia - Martin Sabol - 2000. 2. The 600mm long skull that i mentionned in my previous post concerned a personal communication with a paleontologist who had confirmed to me that the longest skull he had measured was 600mm in length. 3. The longest skull that i know for a cave bear is 715mm. Source: Zeme_Ceske_Zijic_Fossilni - Josef Kafka - 1901. As the source is old, i take this data with cautious and i prefer to be conservative but i don't exclude the possibility of such length. But for the moment, 571mm is for me the longest complete skull that i know. 4. The longest skulls that i know in extant brown bears range between 470mm and 500 mm in length; Source: Steppe brown bear Ursus arctos “priscus” from the Late Pleistocene of Europe. They mostly belongs to gigantic Kodiak bears where the largest specimens are 2 times heavier than the largest prehistoric big cats. 5. Concerning the giant skulls (between 550mm and 650mm) that i mentionned in my previous post, here is the source: Carnivores record and Palaeolithic bear cult in Europe: a review from Radochowska Cave (Sudety Mts, SW Poland) Historical Biology An International Journal of Paleobiology ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/ghbi20 I give you the citation: The body and skull size and its general reduction over the last 15 kyr in Europe was found to be more informative (Marciszak et al.2015; 2017, 2019a, c). Skulls of Eurasian Late Pleistocene brown bears are far larger than those Holocene or recent specimens of the nominative subspecies. The mean of the total length of skulls of the Late Pleistocene individuals is 430 mm (380–480 mm, n = 22) for males and 350 mm (320–380 mm, n = 7) for females. The Holocene and recent individuals are far smaller. The mean of the total skull length is equal to 360 mm (335–390 mm, n = 0) for males and less than 300 mm (270–355 mm, n = 82) for females. The skull length of Holocene and extant Carpathian U. arctos males does not exceed 400 mm and 350 mm in females. Other authors (Kohl and Stugren 1981; Sládek and Štollmann 1985; Jakubiec 2001) obtained the same results for populations from Central and Eastern Europe. Similar decreasing size process was observed for the West Siberian brown bear (Moskvitina et al. 2017). Skulls of U. a. priscus are comparable with the record-sized ones of the largest recent subspecies of U. arctos, living around the Bering Sea. The maximum values obtained for the Late Pleistocene and largest recent individuals are similar and range between 470 and 500 mm for males (Heptner and Naumov 1967; Zavatskij 1978; Baryshnikov 2007). The world record Kodiak bear killed in 1948 had the skull of 487 mm long (Couturier 1954). Analysis of an abundant material of U. arctos across European sites and collections showed that there are still even larger Late Pleistocene specimens among them. Some fragmentary skulls from the Netherlands, Germany or Poland showed similar estimated length of 550–650 mm. U. a. priscus in overall has the size comparable with the largest extant individuals. Big Late Pleistocene specimens exceed the maximal value of the recent U. arctos. Best regards.
07-03-2023, 02:47 AM
( This post was last modified: 07-03-2023, 02:48 AM by hibernours
Edit Reason: orthography
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I can add these informations:
We have a mandible which is at least 360mm in length (Fig 6 D) and it belongs to a brown bear (confirmed by DNA) and the bear was still growing... So we apply the ratio 1.47 for cranial total length / mandibular length (the same used in the paper about Huracan) we obtain a skull length around 529,2 mm for a bear which was not fully grown. If you know the ratio about cranial total length / mandibular length for brown bear, please share it... Source: The history of bears (Ursidae, Carnivora, Mammalia) from Silesia (Southern Poland) and the neigh Bouring areas - 2020. Now, i remember you that we have a mandible of Arctotherium angustidens which is 395mm in length. If we apply the same ratio, we have a skull around 580 mm. Given the fact that short faced bears didn't have large skulls relative to their body size, i let you imagine how big was this specimen of Arctotherium angustidens... |
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