Eopinacosaurus
| Eopinacosaurus Temporal range: Cretaceous, | |
|---|---|
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| Holotype | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Thyreophora |
| Clade: | †Ankylosauria |
| Family: | †Ankylosauridae |
| Subfamily: | †Ankylosaurinae |
| Genus: | †Eopinacosaurus Penkalski, 2026 |
| Type species | |
| †Pinacosaurus mephistocephalus Godefroit et al. 1999 | |
| Synonyms | |
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Eopinacosaurus (meaning "dawn Pinacosaurus") is an extinct genus of ankylosaurid armored dinosaur known from the Late Cretaceous (Campanian age) Bayan Mandahu Formation of China and Djadokhta Formation of Mongolia. The genus contains a single species, Eopinacosaurus mephistocephalus, which was originally assigned to the coeval genus Pinacosaurus.
Discovery and taxonomy
In 1996, a Belgian-Chinese expedition discovered a large, articulated skeleton in the Bayan Mandahu Formation of China. In 1999, Pascal Godefroit and colleagues named this specimen, accessioned as IMM 96BM3/1, as a new species of the genus Pinacosaurus, P. mephistocephalus. The specific name is a contraction of Mephistopheles and the Greek κεφαλή, kephalè, "head", in reference to the "devilish" squamosal horns.[1] In 2010, Gregory S. Paul suggested that P. mephistocephalus were a junior synonym of P. grangeri.[2] It was considered a valid species by Robert Hill in 2012, based on the "secondary dermal" (squamosal) horns and narial characteristics. Victoria Arbour and Michael Burns have confirmed that the species was valid.[3]
In 2026, Paul Penkalski transferred P. mephistocephalus to a new genus, Eopinacosaurus.[4]
Classification
Eopinacosaurus is regarded as a member of the ankylosaurid subfamily Ankylosaurinae, although phylogenetic analyses including it (as "Pinacosaurus" mephistocephalus) since its description have recovered it in a variable position within the clade and in relation to the Pinacosaurus type species, P. grangeri. In 2023, Raven and colleagues recovered it diverging immediately before P. grangeri. These results are displayed in the cladogram below,[5] though later expansions and modifications of this matrix recovered both Pinacosaurus species as sister taxa.[6][7]
In his 2026 revision of the genus Pinacosaurus, Penkalski performed a specimen-level analysis of fossils regarded as belonging to the genus in addition to putative close Asian relatives. These results are displayed in the cladogram below:[4]
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References
- ↑ Godefroit, P.; Pereda-Suberbiola, X.; Li, H.; Dong, Z. M. (1999). "A new species of the ankylosaurid dinosaur Pinacosaurus from the Late Cretaceous of Inner Mongolia (P.R. China)" (PDF). Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre. 69 (supp. B): 17–36.
- ↑ Paul, G. S. (2010). The Princeton Field Guide to Dinosaurs. Princeton, New Jersey: Princeton University Press. p. 232. ISBN 978-0-6911-3720-9.
- ↑ Arbour, V. M. (2014). Systematics, evolution, and biogeography of the ankylosaurid dinosaurs (PDF) (PhD Thesis). University of Alberta.
- 1 2 Penkalski, Paul (2026-05-12). "The morphology and systematics of Pinacosaurus". Historical Biology: 1–42. doi:10.1080/08912963.2026.2633178. ISSN 0891-2963.
- ↑ Raven, T. J.; Barrett, P. M.; Joyce, C. B.; Maidment, S. C. R. (2023). "The phylogenetic relationships and evolutionary history of the armoured dinosaurs (Ornithischia: Thyreophora)". Journal of Systematic Palaeontology. 21 (1). 2205433. Bibcode:2023JSPal..2105433R. doi:10.1080/14772019.2023.2205433.
- ↑ Xing, Lida; Niu, Kecheng; Mallon, Jordan; Miyashita, Tetsuto (2023). "A new armored dinosaur with double cheek horns from the early Late Cretaceous of southeastern China". Vertebrate Anatomy Morphology Palaeontology. 11. doi:10.18435/vamp29396. ISSN 2292-1389.
- ↑ Agnolín, Federico L.; Rozadilla, Sebastián; Marsà, Jordi García; Álvarez Nogueira, Rodrigo; Miner, Santiago; Álvarez-Herrera, Gerardo; Novas, Fernando E.; Pol, Diego (2026-01-13). "New remains of the armored dinosaur Patagopelta cristata Riguetti et al. 2022 (Ornithischia, Parankylosauria) from the Late Cretaceous of Patagonia, Argentina". Historical Biology: 1–64. doi:10.1080/08912963.2025.2583504. ISSN 0891-2963.
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