Elmisaurus

Elmisaurus Temporal range: Late Cretaceous, 70 Ma PreЄ Є O S D C P T J K Pg N ↓
Skeletal restoration showing elements known before 2015
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Family:	†Caenagnathidae
Subfamily:	†Elmisaurinae
Genus:	†Elmisaurus Osmólska, 1981
Species:	†E. rarus
Binomial name
Elmisaurus rarus Osmólska, 1981
Synonyms
Chirostenotes rarus (Osmólska, 1981)

Elmisaurus is an extinct genus of dinosaur from the Late Cretaceous. It was a theropod belonging to the Oviraptorosauria. Its fossils have been found in Mongolia. It is known from foot and hand bones.

Discovery

Frontal bone, indicating the presence of a crest

In 1970 a paleontological Polish-Mongolian expedition discovered two fragmentary specimens of a small theropod in the Ömnögovĭ province of Mongolia. The type species, Elmisaurus rarus, was named and described by Halszka Osmólska in 1981. The generic name is derived from Mongol elmyi or ölmyi, "foot sole" as the type specimen consisted of a metatarsus. The specific name means "rare" in Latin. The holotype is ZPAL MgD-I/172, a left metatarsus fused with the tarsalia. There are two paratypes: ZPAL MgD-I/98, consisting of a right hand and foot, and ZPAL MgD-I/20, the upper part of the left metatarsus of a larger individual.^[1]

A second species, Elmisaurus elegans, was named in 1989 by Philip J. Currie.^[2] This represented a North American form originally described as a species of Ornithomimus by William Arthur Parks in 1933, based on specimen ROM 781, a foot.^[3] Currie also referred the material of the American form Caenagnathus sternbergi, based on a jaw fragment, to Elmisaurus elegans. Due to their poor preservation and geographical distance from the type species, the classification of the American forms has been contentious. In 1997, Hans-Dieter Sues stated that this supposed second species of Elmisaurus should be referred to Chirostenotes, as a Chirostenotes elegans,^[4] though this position was not accepted by Currie.^[5] However, other researchers, including Maryanska, Osmólska, and their colleagues, followed Sues in reassigning E. elegans to Chirostenotes.^[6]

In a 2001 study conducted by Bruce Rothschild and other paleontologists, 23 foot bones referred to Elmisaurus were examined for signs of stress fracture, but none were found.^[7]

Classification

Life restoration

The cladogram below follows an analysis by Longrich et al. in 2013, which found Elmisaurus to be a Caenagnathid.^[8]

Caenagnathidae	Microvenator celer unnamed Gigantoraptor erlianensis unnamed Caenagnathasia martinsoni Elmisaurus rarus Caenagnathinae Leptorhynchos elegans Leptorhynchos gaddisi Hagryphus giganteus unnamed Chirostenotes pergracilis Caenagnathus collinsi Anzu wyliei

See also

• Timeline of oviraptorosaur research

References

1. Osmólska, H. (1981). Coossified tarsometatarsi in theropod dinosaurs and their bearing on the problem of bird origins. Palaeontologica Polonica 42:79-95.
2. Currie, P.J. (1989). "The first records of Elmisaurus (Saurischia, Theropoda) from North America." Canadian Journal of Earth Sciences 26(6):1319-1324
3. Parks, W.A. (1933). New species of dinosaurs and turtles from the Upper Cretaceous formations of Alberta. University of Toronto Studies, Geological Series 34:1-33.
4. Sues, H.-D. (1997). "On Chirostenotes, a Late Cretaceous oviraptorosaur (Dinosauria: Theropoda) from western North America." Journal of Vertebrate Paleontology 17(4):698-716.
5. Currie, P.J., 2005, "Theropods, including birds". In: Currie, P.J. and Koppelhus E.B. (eds). Dinosaur Provincial Park, a spectacular ecosystem revealed, Part Two, Flora and Fauna from the park. Indiana University Press. pp. 367-397
6. Maryanska, Osmolska and Wolsan, (2002). "Avialan status for Oviraptorosauria." Acta Palaeontologica Polonica, 47(1): 97-116.
7. Rothschild, B., Tanke, D. H., and Ford, T. L., 2001, Theropod stress fractures and tendon avulsions as a clue to activity: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 331-336.
8. Longrich, N. R.; Barnes, K.; Clark, S.; Millar, L. (2013). "Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae". Bulletin of the Peabody Museum of Natural History. 54: 23. doi:10.3374/014.054.0102.