Open Paleo

Plesiohadros

Tsogtbaatar et al., 2014 PLEH-see-o-HAH-dros

From Greek 'plesios' meaning 'near' and 'hadros' meaning 'thick' (as in Hadrosauridae), meaning 'near to hadrosaurids.'

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

Plesiohadros is an extinct genus of hadrosauroid dinosaur. It is known from a partial skeleton including the skull collected at Alag Teg locality, from the Campanian Alagteeg Formation of southern Mongolia. The type species is Plesiohadros djadokhtaensis.

Diagnosis

  1. Prefrontal flares dorsolaterally to form a rugose, everted, wing-like rim around rostrodorsal orbital margin
  2. Dentary teeth with one or two accessory ridges mesial and distal to primary carina
  3. Diastema between first dentary tooth and predentary approximately one-third of tooth row length
  4. Dentary tooth row does not extend beyond apex of coronoid process
  5. Reflected rim around oral margin of premaxilla
  6. Premaxillary bill constricted abruptly behind oral margin

Species

Plesiohadros djadokhtaensis Tsogtbaatar et al., 2014

Type species

Named for the Djadokhta Formation of Mongolia.

Holotype
MPC-D 100/745 , Paleontological Center, Mongolian Academy of Sciences
Material
Partial skull, lower jaw, cervical vertebra, hyoid, metacarpals, and phalanges.
Horizon
Alagteeg Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Alag Teeg, Ömnögovi, Mongolia

References

  1. Tsogtbaatar, K.; Weishampel, D. B.; Evans, D. C.; Watabe, M. (2014). A new hadrosaurid (Plesiohadros djadokhtaensis) from the Late Cretaceous Djadokhtan Fauna of southern Mongolia. Hadrosaurs 108-135. Indiana University Press. tsogtbaatar2014a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length estimate, and the appearance features.

    jones2026a