Maleevus

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Maleevus
Temporal range: Late Cretaceous, 90Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Dinosauria
Order: Ornithischia
Suborder: Ankylosauria
Genus: Maleevus
Tumanova 1987
Species: M. disparoserratus
Binomial name
Maleevus disparoserratus

Maleevus is a genus of herbivorous ankylosaurid dinosaur from the late Cretaceous, around 90 million years ago, of Mongolia.

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. The type species remains Syrmosaurus disparoserratus, the combinatio nova is Maleevus disparoserratus.[3] In 1991, George Olshevsky named the species as a Pinacosaurus disparoserratus.[4] 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.[5]

The preserved maxillae have length of about twelve centimetres. This indicates that Maleevus was a medium-sized ankylosaur.

Syrmosaurus disparoserratus was by Maleev placed in the Syrmosauridae.[1] Today it is seen as a member of the Ankylosauridae.

See also[edit]

References[edit]

  1. ^ a b c Maleev E.A., 1952, "Новый анқилосавр из вернего мела Монголии", Doklady Akademii Nauk, SSSR 87: 273-276
  2. ^ T. Maryańska, 1977, "Ankylosauridae (Dinosauria) from Mongolia", Palaeontologia Polonica 37: 85-151
  3. ^ T.A. Tumanova, 1987, "Pantsirnyye dinozavry Mongolii", Trudy Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya 32: 1-80
  4. ^ Olshevsky, G., 1991, A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2, 196 pp
  5. ^ Arbour, Victoria Megan, 2014, Systematics, evolution, and biogeography of the ankylosaurid dinosaurs. Ph.D thesis, University of Alberta