Saurischia Theropoda Tetanurae Coelurosauria Oviraptorosauria Caenagnathidae [Carnivore]
Caenagnathidae: Sternberg, 1940, Cracraft, 1971, Genus type: Caenagnathus Sternberg, 1940.
Diagnosis: Moderately large oviraptorosaurs, the lower jaw of which is elongated and concave in the occlusal part, low adductoral projection, elongated symphysis and narrowed lateral opening.
Composition: One genus Caenagnathus Sternberg, 1940.
Comparison: According to the type of lower jaw structure the caenagnathid is principally similar with that of the oviraptorid and does not have analogues among other toothless theropods. At the same time its general proportions and the character of the parts composing it are basically different from that of the lower jaw of oviraptorids. Among the characteristics that differentiate the caenagnathids are the size and configuration of the occlusal 16 part, the degree of development of the adductoral extension, the character of the symphysis, and the shape and size of the lateral opening.
Remarks: During the first description of the caenagnathids were placed in an independent order of birds (Sternberg, 1940), which found support later (Russell, 1964; Cracraft, 1971), although ornithologists denied the presence of bird characteristics and stressed the common reptilian structure of the lower jaw (Wetmore, 1956, 1960). Later finds of the oviraptorids in Mongolia led to the placement of the caenagnathids with the theropods (Osmolska, 1976).
Cretaceous Late Canada
|Caenagnathus collinsi - Judith River Group (Wedge), Alberta|
|Caenagnathus sternbergi - Judith River Group (Wedge), Alberta|
|Chirostenotes pergracilis - Judith River Group (Wedge), Horseshoe Canyon Formation, Alberta|
|Elmisaurus elegans - Judith River Group (Wedge), Alberta|
|Macrophalangia canadensis - Judith River Group (Wedge), Alberta|
|Ornithomimus elegans - Red Deer River, Oldman Formation, Judith River Group (Wedge), Alberta|
Cretaceous Late US
|Caenagnathus sternbergi - Two Medicine Formation, Montana|
|Ojoraptorsaurus boerei||Ojo Alamo Sandstone, New Mexico|
Cretaceous Late Kazakhstan
|Caenagnathasia martinsoni||?Bostobe Svita Bostobinskaya Svita|
Cretaceous Late Mongolia
|Elmisaurus rarus||Nemegt Formation, Omnogov|
Cretaceous Late Uzbekistan
|Caenagnathasia martinsoni||Bissekt Formation|