Arctodus simus

Davis, Matt, Nye, Benjamin D., Sinatra, Gale M., Swartout, William, Sjӧberg, Molly, Porter, Molly, Nelson, David, Kennedy, Alana A. U., Herrick, Imogen, Weeks, Danaan DeNeve & Lindsey, Emily, 2022, Designing scientifically-grounded paleoart for augmented reality at La Brea Tar Pits, Palaeontologia Electronica (a 9) 25 (1), pp. 1-37 : 21-22

Arctodus simus

( Figure 13 )

Appearance. Our model of the short-faced bear follows the reconstruction done by Oscar San- Isidro for Figueirido et al. (2010). The coloration ( Figure 13 ) is based on the closest extant relative of Arctodus simus , the spectacled bear ( Tremarctos ornatus ). Pelage can vary markedly among closely-related groups, especially bears; despite the name “black” bear, Ursus americanus famously has multiple distinctive color morphs besides black including white, cinnamon, and brown (Caro, 2013). T. ornatus differs from A. simus in numerous life history characteristics including size, carnivory, and arboreality (Vela-Vargas et al., 2021). However, T. ornatus inhabits a very wide variety of habitats today from cloud forest through scrub desert (Vela-Vargas et al., 2021) and black is a common color for most extant bears (Caro, 2013), so there is no reason to think this coloration could not have been successful for A. simus in the Pleistocene savanna ecosystem of the Los Angeles Basin.

Of all our models, A. simus is probably the one we are least satisfied with from a realism perspective. In our efforts to accurately match our fossil proportions, we fell prey to the common paleoart pitfall of “shrink wrapping” soft tissues around skeletal anatomy. This led to a rather gangly looking bear. Given another chance, we would probably bulk out the model a bit to account for the large fat reserves thought to be ancestral to Tremarctinae

DAVIS ET AL.: LA BREA TAR PITS PALEOART

(Fowler et al., 2021) and long hair that the short-faced bear likely had. Although preserved skin is unknown for the short-faced bear, it seems reasonable that it would have had a full coat even though its large size may have pushed it toward gigantothermy. Their closest living relatives, spectacled bears, have long fur and even large bears like Mexican grizzlies ( Ursus arctos horribilis ) that lived in hot, dry habits had long, shaggy fur (Merriam, 1914).

Behavior. We used the polar bear ( Ursus maritimus ) as a reference for walking animations as it has similar leg proportions to the short-faced bear and is the largest extant bear ( Figueirido et al., 2010). We avoided the long running controversy over short-faced bears’ cursorial habits by only showing them in a meandering gait ( Figueirido et al., 2010).

Western Horse

Figures

FIGURE 13. Low poly reconstruction of the extinct short-faced bear (Arctodus simus). To view this model in 3D, please see the online version of this article.