Maleevus
Maleevus Temporal range: Late Cretaceous | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | †Ornithischia |
Clade: | †Thyreophora |
Clade: | †Ankylosauria |
Family: | †Ankylosauridae |
Genus: | †Maleevus Tumanova, 1987 |
Species: | †M. disparoserratus |
Binomial name | |
†Maleevus disparoserratus Tumanova, 1987 | |
Synonyms | |
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Maleevus (named in honour of Evgeny Maleev) is an extinct genus of herbivorous ankylosaurid dinosaur from the late Cretaceous, around 90 million years ago (possibly 98-83 Ma), of Mongolia.[1]
Discovery and naming
[edit]Between 1946 and 1949, Soviet-Mongolian expeditions uncovered fossils at Shiregin Gashun. In 1952, Soviet palaeontologist Evgenii Aleksandrovich Maleev named some ankylosaurian bone fragments as a new species of Syrmosaurus: Syrmosaurus disparoserratus. The specific name refers to the unequal serrations on the teeth.[1]
The holotype, PIN 554/I, was found in a layer of the Bayan Shireh Formation dating from the Cenomanian-Santonian. It consists of two upper jawbones, left and right maxillae. Maleev erroneously assumed these represented the lower jaws. Referred was specimen PIN 554/2-1, the rear of the skull of another individual.[1]
In 1977, Teresa Maryańska noted a similarity with another Mongolian ankylosaur, Talarurus, in that both taxa have separate openings for the ninth to twelfth cerebral nerve; she therefore renamed the species as Talarurus disparoserratus.[2] Having determined that Syrmosaurus is a junior synonym of Pinacosaurus, Soviet palaeontologist Tatyana Tumanova named the material as a new genus Maleevus in honor of Maleev in 1987.[3] The type species remains Syrmosaurus disparoserratus, the combinatio nova is Maleevus disparoserratus.[4] In 1991, George Olshevsky named the species as a Pinacosaurus disparoserratus.[5] In 2014, Victoria Megan Arbour determined that the rear skull was not different from that of many other ankylosaurids and that the single distinguishing trait of the teeth, a zigzag pattern on the cingulum, was shared with Pinacosaurus. She concluded that Maleevus was a nomen dubium.[6]
Size
[edit]The preserved maxillae have length of about twelve centimetres.[1] This indicates that Maleevus was a medium-sized ankylosaur of around 6 metres (20 ft). The height and weight of Maleevus is unknown due to the lack of known remains. (size estimates based on the related Talarurus).
Classification
[edit]Syrmosaurus disparoserratus was by Maleev placed in the Syrmosauridae.[1] Today Maleevus is seen as a member of the Ankylosauridae.
See also
[edit]References
[edit]- ^ a b c d e Maleev E.A., 1952, "Новый анқилосавр из вернего мела Монголии", Doklady Akademii Nauk, SSSR 87: 273-276
- ^ T. Maryańska, 1977, "Ankylosauridae (Dinosauria) from Mongolia", Palaeontologia Polonica 37: 85-151
- ^ The armored dinosaurs of Mongolia [in Russian], Tumanova - 1987.
- ^ T.A. Tumanova, 1987, "Pantsirnyye dinozavry Mongolii", Trudy Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya 32: 1-80
- ^ Olshevsky, G., 1991, A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2, 196 pp
- ^ Arbour, Victoria Megan, 2014, Systematics, evolution, and biogeography of the ankylosaurid dinosaurs. Ph.D thesis, University of Alberta