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Amurosaurus

Bolotsky & Kurzanov, 1991 a-MOO-uhr-o-SOR-us /əˌmʊərəˈsɔːrəs/

Named for the Amur River near where its remains were found, combined with Greek 'sauros' meaning 'lizard', meaning 'Amur lizard'.

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

Amurosaurus is a genus of lambeosaurine hadrosaurid dinosaur found in Late Cretaceous (70 to 66 million years ago) deposits of what is now eastern Asia.

Diagnosis

  1. Largely dorsally directed, helmet-shaped hollow supracranial crest, slightly longer anteroposteriorly than dorsoventrally tall (height/length ratio ~0.9)
  2. Robust, knob-like ventral end of the jugal anterior process, strongly posteriorly curved
  3. Several anterodorsally-posteroventrally oriented lateral foramina on the maxilla, the last very large and partly obscured by the jugal contact
  4. Narrow infratemporal region of the jugal, about 70% as wide as the orbit
  5. Anterior third of the strongly ventrally bowed parietal sagittal crest low, with a transversely wide, posteriorly tapered dorsal outline
  6. Mesiodistally wide maxillary tooth crowns (about 1.2-1.3 teeth per cm)
  7. Posterolateral process of the sternum slightly shorter than the anteromedial plate, and preacetabular process of the ilium gently ventrally deflected

Species

Amurosaurus riabinini Bolotsky & Kurzanov, 1991

Type species

Named for the late Russian paleontologist Anatoly Riabinin, who conducted the first Russian expeditions to recover dinosaur remains in the Amur region in 1916 and 1917.

Holotype
AEHM 1/12 , Amur Natural History Museum of the Institute of Geology and Nature Management, Russian Academy of Sciences
Material
Associated left maxilla and dentary.
Horizon
upper Udurchukan Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Blagoveschensk, Amur, Russia

Synonyms of the genus

Name Type Reason
Sahaliyania junior subjective Wulaga (Yuliangzi Formation) lambeosaurine material assigned to Sahaliyania is indistinguishable from Amurosaurus riabinini; Xing and colleagues (2022) formally synonymized Sahaliyania with Amurosaurus.

References

  1. Bolotsky, Y. L.; Kurzanov, S. M. (1991). Gadrosavry Priamuriy [The hadrosaurs of the pre-Amur Region]. Geology of the Pacific Ocean Border 94-103. Amur KNII. bolotsky1991a
  2. Xing, H.; Gu, W.; Hai, S.; Yu, T.; Han, D.; Zhang, Y.; Zhang, S. (2022). Osteological and taxonomic reassessments of Sahaliyania elunchunorum (Dinosauria, Hadrosauridae) from the Upper Cretaceous Yuliangzi Formation, northeast China. Journal of Vertebrate Paleontology 41(6): e2085111. Informa UK Limited. doi:10.1080/02724634.2021.2085111

    Refers the Wulaga lambeosaurine material (formerly Sahaliyania elunchunorum) to Amurosaurus riabinini, synonymizing Sahaliyania, and provides an amended diagnosis.

    xing2022a