''Maleevus'' (named in honour of

Evgeny Maleev Evgeny Aleksandrovich Maleev (, ; 25 February 1915 – 12 April 1966) was a Soviet and Russian paleontologist who did most of his research on reptiles and Asian fossils, such as the naming of the ankylosaur '' Talarurus'' and theropods '' Tar ...

) is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of herbivorous

ankylosaur Ankylosauria is a group of herbivorous dinosaurs of the clade Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful l ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

from the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

, around 90

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

(possibly 98-83 Ma), of

Mongolia Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...

Discovery and naming

Between 1946 and 1949, Soviet-Mongolian expeditions uncovered fossils at Shiregin Gashun. In 1952,

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

palaeontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Evgenii Aleksandrovich Maleev Evgeny Aleksandrovich Maleev (, ; 25 February 1915 – 12 April 1966) was a Soviet and Russian paleontologist who did most of his research on reptiles and Asian fossils, such as the naming of the ankylosaur '' Talarurus'' and theropods '' Tar ...

named some ankylosaurian bone fragments as a new species of '' Syrmosaurus'': ''Syrmosaurus disparoserratus''. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

refers to the unequal serrations on the teeth.Maleev E.A., 1952, "Новый анқилосавр из вернего мела Монголии", ''Doklady Akademii Nauk, SSSR'' 87: 273-276 The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, PIN 554/I, was found in a layer of the

Bayan Shireh Formation The Bayanshiree Formation (also known as Baynshiree/Baynshire, Baynshirenskaya Svita, Baysheen Shireh, or Bayan Shireh) is a geological formation in Mongolia, that dates to the Cretaceous period. It was first described and established by Vasilie ...

dating from the

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

. It consists of two upper jawbones, left and right

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

e. Maleev erroneously assumed these represented the lower jaws. Referred was specimen PIN 554/2-1, the rear of the skull of another individual. In 1977,

Teresa Maryańska Teresa Maryańska (1937 – 3 October 2019) was a Polish paleontologist who specialized in Mongolian dinosaurs, particularly pachycephalosaurians and ankylosaurians. She is considered not only as one of Poland's but also one of the world's leadin ...

noted a similarity with another Mongolian ankylosaur, ''

Talarurus ''Talarurus'' ( ; meaning "basket tail" or "wicker tail") is a genus of ankylosaurid dinosaur that lived in Asia during the Late Cretaceous period, about 96 million to 89 million years ago. The first remains of ''Talarurus'' were discovered in 1 ...

'', in that both taxa have separate openings for the ninth to twelfth

cerebral nerve Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and f ...

; she therefore renamed the species as ''Talarurus disparoserratus''. Having determined that ''Syrmosaurus'' is a

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

of ''

Pinacosaurus ''Pinacosaurus'' (meaning "Plank lizard") is a genus of ankylosaurid thyreophoran dinosaur that lived in Asia during the Late Cretaceous (Campanian, roughly 75 to 71 million years ago), mainly in Mongolia and China. The first remains of the genu ...

'', Soviet palaeontologist

Tatyana Tumanova Tatiana (or Tatianna, also romanized as Tatyana, Tatjana, Tatijana, etc.) is a female name of Sabine-Roman origin that became widespread in Eastern Europe. Origin Tatiana is a feminine, diminutive derivative of the Sabine—and later Latin� ...

named the material as a new genus ''Maleevus'' in honor of Maleev in 1987. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

remains ''Syrmosaurus disparoserratus'', the ''

combinatio nova In biological taxonomy, a combinatio nova (abbreviated comb. nov. or n. comb.) refers to the formal renaming of an organism's scientific name when it is transferred to a different genus, reclassified within a different species, or its taxonomic ...

'' is ''Maleevus disparoserratus''. In 1991, George Olshevsky named the species as a ''Pinacosaurus disparoserratus''.Olshevsky, G., 1991, ''A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia''. Mesozoic Meanderings 2, 196 pp 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 ''

''. She concluded that ''Maleevus'' was a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

''.Arbour, Victoria Megan, 2014, ''Systematics, evolution, and biogeography of the ankylosaurid dinosaurs''. Ph.D thesis, University of Alberta

Size

The preserved maxillae have a length of about . This indicates that ''Maleevus'' was a medium-sized ankylosaur at around in length based on the related ''

''. The height and weight of ''Maleevus'' are unknown due to the lack of known remains.

Classification

''Syrmosaurus disparoserratus'' was by Maleev placed in the

Syrmosauridae Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known ankylosaurids date to around 122 million years ago and went extinct 66 million years ago during the Cretaceous–Pal ...

. Today ''Maleevus'' is seen as a member of the

Ankylosauridae Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known ankylosaurids date to around 122 million years ago and went extinct 66 million years ago during the Cretaceous–Pal ...

References

{{Taxonbar, from=Q1755632 Ankylosauria Dinosaur genera Turonian dinosaurs Fossil taxa described in 1987 Dinosaurs of Mongolia

Discovery and naming

Size

Classification

See also

References