Open Paleo

Epichirostenotes

Sullivan et al., 2011 ep-ih-KI-roh-steh-NO-teez

From Greek epi- (above/upon, in the sense 'after in time') + Chirostenotes (the related oviraptorosaurian genus): 'above Chirostenotes', because it lived stratigraphically and temporally after Chirostenotes.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Epichirostenotes is a genus of oviraptorosaurian dinosaur from the Late Cretaceous. Epichirostenotes is known from an incomplete skeleton found in 1923 at the Horseshoe Canyon Formation, in strata dated to about 72 million years ago. It was first named by Robert M. Sullivan, Steven E. Jasinski and Mark P.A. van Tomme in 2011 and the type species is Epichirostenotes curriei. Its holotype, ROM 43250, had been assigned to Chirostenotes pergracilis by Hans-Dieter Sues in 1997.

Diagnosis

  1. Braincase much deeper than long, with distinctly verticalized basicranial region
  2. Otic region with deep but anteroposteriorly narrow lateral depression
  3. Synsacrum composed of six co-ossified vertebrae with pneumatic foramina
  4. Ischium long and expanded posteriorly, broad behind obturator process, with obturator process expanded and triangular
  5. Prominent anterior proximal hook-like projection of the ischia

Species

Epichirostenotes curriei Sullivan et al., 2011

Type species

Named in honor of Philip J. Currie for scholarly work on Late Cretaceous theropod dinosaurs.

Holotype
ROM 43250 , Royal Ontario Museum
Material
Incomplete skeleton including braincase, otic region, synsacrum of six co-ossified vertebrae, ischia, and other postcranial elements.
Horizon
Horseshoe Canyon Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
about 1/4 mile above John Neills Ranch, east side of the Red Deer River, Alberta, Canada

References

  1. Sullivan, R. M.; Jasinski, S. E.; Van Tomme, M. P. A. (2011). A new caenagnathid Ojoraptorsaurus boerei, n. gen., n. sp. (Dinosauria, Oviraptorosauria), from the Upper Cretaceous Ojo Alamo Formation (Naashoibito Member), San Juan Basin, New Mexico. Fossil Record 3 53: 418-428. New Mexico Museum of Natural History and Science. sullivan2011a
  2. Sues, H. D. (1997). On Chirostenotes, a Late Cretaceous oviraptorosaur (Dinosauria: Theropoda) from western North America. Journal of Vertebrate Paleontology 17(4): 698-716.

    Describes the holotype and gives its locality as John Neills Ranch, from Lindblad's 1923 field diary, 75 feet above the river flat.

    sues1997a