[MM] Ctenacodon sp.
DESCRIBER Simpson, 1928 / Engelmann & Callison, 1998 / Engelmann, 2004
TIME Jurassic Late
FOSSILSITE Dinosaur National Monument, Ninimile Hill, Morrison Formation, Wyoming, United States
FALL UNDER Ctenacodon serratus
Ctenacodon serratus (Marsh, 1879 ) > Ctenacodon laticeps (Marsh, 1881) > Ctenacodon scindens (Simpson, 1928) > Ctenacodon sp. (Simpson, 1928 / Engelmann & Callison, 1998 / Engelmann, 2004 ) Collections of fossil mammals from the Upper Jurassic Morrison Formation of Dinosaur National Monument (DINO), Utah, have been made following discovery of a microvertebrate site (DNM 96) there in 1984 (Engelmann et al., 1989; Chure and Engelmann, 1989). Specimens of fossil mammals have been collected at the site by both hand-quarrying and screen-washing methods. Screen washing of sediment that had no apparent indication of contained fossils when initially quarried has produced a relatively diverse fauna that otherwise never would have come to light. But most of the numerous mammalian fossil specimens recovered by screen washing are isolated teeth. Complementing these specimens obtained by screen washing is a small number of specimens discovered and recovered by hand quarrying. Although few in number, these specimens are more completely preserved and provide much more information (both paleobiological and systematic) about the animals. Engelmann and Callison (1998) described at DINO, selecting from the large number of isolated teeth those specimens that were readily identifiable as representing new or existing taxa. The greatest proportion of mammalian fossils consists of isolated teeth of multituberculates that range in quality from small fragments to complete teeth with relatively unworn crowns. Most of these teeth were referred (Engelmann and Callison, 1998) to the genus Ctenacodon, either C. serratus (for lower teeth) or C. laticeps (for uppers), based on their similarity in size and morphology to the sample of Ctenacodon from Como Bluff, Wyoming. Of the many specimens left undescribed, however, some remained unidentifiable despite relatively good preservation. A damaged, partial palate of the multituberculate Ctenacodon has helped identify some of these unknown specimens and extends our knowledge of this taxon. (Engelmann, 2004)