ArchaeotheriumÌýis anÌýentelodont which areÌýextinct membersÌýof the artiodactyls (an order that includes today’s cattle, deer, and sheep)Ìýthat lived alongside rhinos and early horses on the floodplains of eastern Å·ÃÀ¿Ú±¬ÊÓƵ, Wyoming, South Dakota, Nebraska, and Texas during late Eocene – Oligocene time (ca. 37 – 23 million years ago).ÌýÌýAn adultÌýArchaeotheriumÌýcould reach over 6 feet (2 m) in length, with a large skull over 3 feet (1 m) long. Its long jaws (like the one shown here) and low, rounded cheek teeth suggestÌýArchaeotheriumÌýwas an omnivore,Ìýas bunodont teeth typically suggest an omnivorous diet.ÌýIt may have used itsÌýtusk-like canines to dig tubers and other forms of vegetation out of the ground.ÌýHowever,Ìýrecent studies suggest it was a bone-crusher too.ÌýBones belonging toÌýthe ancient camel,ÌýPoebrotheriumÌýwere found fromÌýthe White River Formation in WyomingÌýwereÌýthought to be killed byÌýArchaeotheriumÌýas punctures match theÌýpremolarsÌýofÌýArchaeotherium.Ìý
Based on its size, body shape, teeth, and diet,ÌýArchaeotheriumÌýis often compared to today’s pigs, and in fact it has been popularly called the Giant Pig from Hell! However,Ìýin 2008 and 2009, a study concluded the entelodonts are closely related to whales and hippos, thus forming the Whippomorpha (Cetancodontamorpha) clade.ÌýWhales are evolved from artiodactyls, thus strengthening the relation between entelodonts.ÌýTheseÌýrecent studies suggest thatÌýArchaeotheriumÌýand entelodontsÌýprobablyÌýwere notÌýa close cousin to today’s pigs at all. ManyÌýArchaeotheriumÌýskulls appear to exhibit injuries, so these large mammals are often interpreted as an argumentative bunch!
Catalog Number: UCM 20457
°Õ²¹³æ´Ç²Ô´Ç³¾²â:ÌýArchaeotherium
Location: Weld Co., Å·ÃÀ¿Ú±¬ÊÓƵAge: Eocene,ÌýChadronian
Stratigraphy: White River Formation, Horsetail Creek MemberÌý
Joeckel, R. 1990. A Functional Interpretation of the Masticatory System and Paleoecology of Entelodonts. Paleobiology 16:459—482
O’Leary, M. A. &ÌýGatesy, J. 2008. Impact of increased character sampling on the phylogeny ofÌýCetartiodactylaÌý(Mammalia): combined analysis including fossils. Cladistics 24, 397-442.
Prothero, D., and S. Foss. 2007. The EvolutionÌýOfÌýArtiodactyls. Johns Hopkins University Press, p. 126—127
Spaulding, M., O’Leary, M. A. &ÌýGatesy, J. 2009. Relationships of Cetacea (Artiodactyla) among mammals: increasedÌýtaxonÌýsampling alters interpretations of key fossils and character evolution.ÌýPLoSÌýONE 4(9): e7062.Ìýdoi: 10.1371/journal.pone.00070672
Sundell, K. A. 1999. Taphonomy of a multiple Poebrotherium kill site – an Archaeotherium meat cache. Journal of Vertebrate Paleontology 19 (Supp. 3), 79A.