Battle beyond Epochs 2 Big Bears and Beardog study

Cons: The smallest in this lineup and the least carnivorous / predatory.


Bison latifrons / Long horned bison
(The late Pleistocene North America) 


Arctodus simus / North American Giant Short faced bear
(The late Pleistocene North America)

BM=c.750 kgs (Christiansen, 1999)

Pros: Outstanding body dimensions, significant reach advantage and strong bite force.

Cons: Not particularily well suited to grappling nor agility, somewhat awkwardly(for lack of a better word) tall and long limbed. 


Agriotherium africanum / African Short faced bear
(The Mio-Pliocene Africa)

BM=c.540 kgs (Sorkin, 2006)

Pros: Very large yet the limbs not too elongated, similar to ursine bears than to tremarctine short faced bears in this respect. Believed to have been the most predatory among bears. The strongest bite force in this lineup.

Cons: One of the smallest competitors.

Arctotherium angustidens / South American Giant Short faced bear
(The middle Pleistocene South America)

BM=c.1000+ kgs*
(*Soibelzon's BM figure(2009) for A. angustidens appears not only somewhat too excessive judging from the size comparison between A. angustidens and the largest Arctodus specimens from Yukon / Nebraska (the specimen 'UVP015', estimated at weighing mean.957 kgs was the largest analysed by Figueirido et.al., 2010), but also the BM of over 1.5 tons would be simply too much for other bears to compete against, so I set the figure for A. angustidens at c.1000 kgs on this occasion. This might be unduly small for the species or might not be, but still larger than any other competitors.)

Pros: Outstanding body dimensions, significant reach advantage and strong bite force. Even larger than A. simus.

Cons: Not particularily well suited to grappling nor agility, somewhat awkwardly tall and long limbed.

Amphicyon ingens / North American Giant Beardog
(The middle Miocene North America)

BM=c.547 kgs (Figueirido et.al., 2011)

Pros: Significantly more carnivorous and predatory than others. Very large yet has agility and leaping advantages. Very versatile predator.

Cons: Perhaps lesser in endurance and less stable than in true bears. Built somewhat similarly to big cats but no killing bite technique.



●Some random updates regarding ancient bear and beardog

[Taxonomic positioning of Beardogs]

Although the family Amphicyonidae('beardogs') has long been considered to have been most closely related to bears based on a number of morphological similarities between the two groups, the recent taxonomic study(Tomiya et.al., 2016) proposes the placement of Amphicyonidae as an early diverging group of caniforms, not particularly closely related to either bears nor dogs(thus, the description of them being closer to dogs on wikipedia article is erroneous). The authors however, still consider the shared presences of deep basioccipital embayment and postscapular fossa among Amphicyonids and Ursids are not found on other carnivorans and merit further disccusion on their closer affinity.


[Short faced bears as omnivorous giants]

Several recent morphological and mechanical researches(Sorkin, 2006, Figueirido et. al., 2009, Figueirido et. al., 2011) agree upon the assumption that tremarctine giant short faced bears were actually omnivorous rather than hyper canivorous as previously assumed but their diet included certain amount of animal material which was obtained mainly by scavenging. This theory seems to be in accord with a lack of adaptations in giant short faced bears to both pursuing or ambushing predation and their peculiar morphological traits: The relatively short and broad, somewhat hyena like rostrum(actually, Figueirido et. al., 2011 reveals that the snout of A. simus was in fact, not particularly short) and the high bite force may have been adaptations for carrion consumption, including bones. The elongated limbs and the huge body size were perhaps the result of adaptations for covering large home range and facilitating kleptoparasitism of carcasses, respectively.

Giant short faced bears probably did occasional big game hunting as well but they may be best interpreted as huge, formidable omnivores whose diet included varying amonts of meat according to food availability(Figueirido et. al., 2011). In a sense, I guess their mode of life should have been similar to that of some populations of North American brown bears but the emphasis may be put greatly more on kleptoparasitism in giant short faced bears. There were significantly greater amount of mega fauna carcasses available in the Pleistocene Americas. This was especially the case where saber toothed cats co-existed, because these specialised hyper carnivores could only consume softer tissues and as a result, relatively large amount of flesh and bone nutrients were left available.

Lastly, I can't be sure if the omnivory theory applies to another 'giant short faced bear', Agriotherium africanum because, unlike Sorkin(2006) who dealt with genera Agriotherium and Arctodus as the same ecomorpho-type as 'short faced bears'(as far as I know, they were only distantly related phylogenetically, but it may also have been the case that Agriotherium was ancestral to tremarctine short faced bears) and concluded omnivorous diet for both, the study by Wroe et. al.(2011) shows a little possibility of Agriotherium africanum being omnivorous, judging from analysis on its craniodental variables.   

©Jagroar