Bears of the Pleistocene

[hibernours]

(07-02-2023, 10:33 AM)johnny rex Wrote:

(06-07-2023, 11:50 AM)hibernours Wrote: 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.

Can I see the link where someone found a 600 mm long bear skull?

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.

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