ammonites
†Leptauchenia major Leidy 1856 (oreodont)

Mammalia - Artiodactyla - Merycoidodontidae

Alternative combination: Pseudocyclopidius major

Synonyms: Brachymeryx feliceps Cope 1877, Cyclopidius densa Loomis 1925, Cyclopidius emydinus Cope 1884, Cyclopidius incisivus Scott 1893, Cyclopidius lullianus Thorpe 1921, Cyclopidius simus Cope 1877, Hadroleptauchenia densa Loomis 1925, Hadroleptauchenia extrema Schultz and Falkenbach 1968, Hadroleptauchenia shanafeltae Schultz and Falkenbach 1968, Leptauchenia densa Loomis 1925, Leptauchenia margeryae Schultz and Falkenbach 1968, Leptauchenia martini Schultz and Falkenbach 1968, Leptauchenia parasimus Schultz and Falkenbach 1968, Pithecistes altageringensis Schultz and Falkenbach 1968, Pithecistes copei Schultz and Falkenbach 1968, Pseudocyclopidius lullianus Thorpe 1921

Full reference: J. Leidy. 1856. Notice of some remains of extinc vertebrated animals. Proceedings of the Academy of Natural Sciences of Philadelphia 163-165

Belongs to Leptauchenia according to B. Lander 1998

Sister taxa: Leptauchenia decora, Leptauchenia eiselyi, Leptauchenia orellaensis

Type specimens:

  • Leptauchenia major: Its type locality is Eagle Nest Butte (Brule), which is in an Arikareean terrestrial horizon in the Brule Formation of South Dakota
  • Brachymeryx feliceps:
  • Cyclopidius emydinus:
  • Cyclopidius incisivus:
  • Cyclopidius lullianus: Its type locality is Big Muddy Creek, which is in an Arikareean terrestrial horizon in Wyoming.
  • Cyclopidius simus:
  • Hadroleptauchenia extrema:
  • Hadroleptauchenia shanafeltae:
  • Leptauchenia densa:
  • Leptauchenia margeryae:
  • Leptauchenia martini: Its type locality is Potato Creek (Sharps A), which is in a Geringian terrestrial horizon in the Sharps Formation of South Dakota.
  • Leptauchenia parasimus:
  • Pithecistes altageringensis: Its type locality is Little Muddy Creek (Niobrara County), which is in an Arikareean terrestrial horizon in Wyoming.
  • Pithecistes copei:

Ecology: ground dwelling herbivore

Average measurements (in mm): P1 6.00 x 6.00, M1 7.00 x 6.00, M3 12.0 x 6.0, m1 10.4 x 7.4, m2 11.0 x 6.0, m3 16.0 x 6.0