Open Paleo

Caenagnathus

Sternberg, 1940 KAY-nag-NAY-thus

From Greek 'kainos' (new, recent) and 'gnathos' (jaw); meaning 'recent jaw', alluding to the novel jaw morphology distinct from then-known birds and reptiles.

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

Caenagnathus is a genus of caenagnathid oviraptorosaurian dinosaur from the late Cretaceous period (Campanian stage, about 75 million years ago). It is known from partial remains including lower jaws, a tail vertebra, hand bones, hind limbs, and pelvis, all found in the Dinosaur Park Formation of Alberta, Canada.

Diagnosis

  1. No teeth present
  2. Dentaries fused at symphysis; pars symphysis relatively long and broad
  3. Rami parallel throughout their length
  4. Mandibular fossa large, elongate with flattened-oval shape, extending 60 mm posteriorly from its anterior border
  5. Articular surface large, oval, and convex with a ridged axis parallel to the direction of the ramus
  6. Mandibular processes (internal, external, and posterior) short and fairly stout, subcircular and horizontal
  7. Anterior tip of the dentary (occlusal beak tip) not upturned

Species

Caenagnathus collinsi Sternberg, 1940

Type species

Named in honor of W. H. Collins, longtime director of the Geological Survey of Canada.

Holotype
CMN 8776 , Canadian Museum of Nature
Material
Complete lower jaw (mandible) except for the ventral border of the right ramus
Horizon
Dinosaur Park Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Quarry 112, Steveville, Alberta, Canada

References

  1. Funston, G. (2020). Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution. Vertebrate Anatomy Morphology Palaeontology 8: 105-153. University of Alberta Libraries. doi:10.18435/vamp29362

    Gives the horizon as "Upper Cretaceous (Campanian) Dinosaur Park Formation".

    funston2020b
  2. Sternberg, R. M. (1940). A toothless bird from the Cretaceous of Alberta. Journal of Paleontology 14(1): 81-85. sternberg1940a
  3. Funston, G. F.; Currie, P. J. (2020). New material of Chirostenotes pergracilis (Theropoda, Oviraptorosauria) from the Campanian Dinosaur Park Formation of Alberta, Canada. Historical Biology. Taylor & Francis. doi:10.1080/08912963.2020.1726908

    Chirostenotes revision providing anatomical evidence that Caenagnathus collinsi is distinct: holotype lacks the upturned dentary tip seen in Chirostenotes.

    funston2020c
  4. Lamanna, M. C.; Sues, H. D.; Schachner, E. R.; Lyson, T. R. (2014). A new large-bodied oviraptorosaurian theropod dinosaur from the latest Cretaceous of western North America. PLoS ONE 9(3): e92022. Public Library of Science (PLoS). doi:10.1371/journal.pone.0092022

    Anzu wyliei description; phylogenetic analysis recovers Caenagnathus collinsi as sister to Anzu, distinct from Chirostenotes — beginning the modern revival of Caenagnathus as a valid genus.

    lamanna2014a