Equus occidentalis (Leidy, 1865)

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 : 22-23

Equus occidentalis

( Figure 14 )

Appearance. Extinct North American Equus is perhaps the taxon where our understanding of external appearance lags the most behind available evidence and methods. The modern horse husbandry industry has developed a detailed understanding of the genetics underlying different coat coloration and patterns (Pruvost et al., 2011). Combined with a prevalent fossil record (Barrón-Ortiz et al., 2017), many sequenced ancient genomes (Orlando, 2020), well-preserved frozen carcasses (Boeskorov et al., 2014), and (at least in Europe) numerous cave paintings (Pruvost et al., 2011), we have the potential to accurately reconstruct the appearance of several fossil equid species. However, application of these techniques in North

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America is hindered by the century old debate of American fossil horse taxonomy and difficulty matching up genetically identified clades with traditional morphospecies (Barrón-Ortiz et al., 2017). While out of the scope of this paper, synthesizing evidence from frozen remains and matching up existing DNA samples of extinct American horses with known coat patterning genes offers a promising direction for future research on North American fossil equids.

For our model ( Figure 14 ) of the western horse ( Equus occidentalis ), we followed the general appearance of Przewalski’s horse ( Equus ferus przewalskii ). Although now thought to actually represent the feral descendants of a very early domestic horse, their dun coats are considered a common ancestral wildtype for horses (Orlando, 2019).

Behavior. We used Przewalski’s horse as an animation reference. We displayed the western horse in groups as all living horses are herd animals, and E. occidentalis is the second most common herbivore found at Rancho La Brea (Stock and Harris, 1992; Bennett and Hoffman, 1999).

Shasta Ground Sloth

Figures

FIGURE 14. Low poly reconstruction of the extinct western horse (Equus occidentalis). To view this model in 3D, please see the online version of this article.