Open Paleo

Elmisaurus

Osmólska, 1981 EL-mi-SAWR-us

From Mongolian elmyi/ölmyi (foot sole) + Greek sauros (lizard): 'foot sole lizard', because the type specimen consisted of a fused metatarsus.

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Elmisaurus is an extinct genus of caenagnathid theropod dinosaur from the Late Cretaceous Nemegt Formation of Mongolia.

Diagnosis

  1. Metatarsal III visible anteriorly for about 90% of its entire length
  2. Length/width ratio of metatarsus 0.18
  3. Metacarpal I about 2/3 the length of phalanx I of digit I
  4. Digit III of manus markedly thinner than digits I and II, which are equally thick
  5. Ventroposterior portions of manus phalanges distinctly thickened at proximal surfaces
  6. Tarsal 4 with an upward process at lateral margin; cross-section of metatarsus semilunar

Species

Elmisaurus rarus Osmólska, 1981

Type species

From Latin 'rarus' meaning 'rare', reflecting the scarcity of this dinosaur's remains in the Nemegt Formation.

Holotype
ZPAL MgD-I/172 , Institute of Paleobiology, Polish Academy of Sciences
Material
Complete left tarsometatarsus (lacking Mt I).
Horizon
Nemegt Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Nemegt, Ömnögovi, Mongolia

References

  1. Osmólska, H. (1981). Coossified tarsometatarsi in theropod dinosaurs and their bearing on the problem of bird origins. Palaeontologica Polonica 42: 79-95. osmólska1981a
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026c
  4. Funston, G. F.; Mendonca, S. E.; Currie, P. J.; Barsbold, R. (2018). Oviraptorosaur anatomy, diversity and ecology in the Nemegt Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 494: 101-120. doi:10.1016/j.palaeo.2017.10.023

    Treats ZPAL MgD-I/98, a specimen Osmólska (1981) referred to the species, as the holotype, and says its precise site in the Western Sayr is not known.

    funston2018a