''Paralitherizinosaurus'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

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 ...

therizinosaurid Therizinosauridae (meaning 'scythe lizards')Translated paper
is an extinct family of derive ...

theropod Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...

dinosaurs from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Osoushinai Formation of

Hokkaido is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...

, Japan. The genus contains a single species, ''Paralitherizinosaurus japonicus'', known from a partial right hand and

cervical vertebra In tetrapods, cervical vertebrae (: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In sauropsid s ...

. ''Paralitherizinosaurus'' represents the youngest

therizinosaur Therizinosaurs (; once called segnosaurs) are an extinct group of large herbivorous theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been foun ...

known from

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Discovery and naming

The ''Paralitherizinosaurus''

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 ...

specimen, NMV-52, was discovered in September 2000 in layers of the Osoushinai Formation (

Yezo Group The Yezo Group is a stratigraphic group in Hokkaido, Japan and Sakhalin, Russia which is primarily Late Cretaceous in age (Aptian to Earliest Paleocene). It is exposed as roughly north–south trending belt extending 1,500 kilometres through centr ...

) in Nakagawa, Hokkaido, Japan, which dates to the early

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

age of the late Cretaceous period. The specimen consists of a partial

and the

metacarpal In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones ( wrist bones), which articulate ...

I, proximal ends of

unguals An ungual (from Latin ''unguis'', i.e. ''nail'') is a highly modified distal toe bone which ends in a hoof, claw, or nail. Elephants and ungulates have ungual phalanx bones, phalanges, as did the sauropods and ceratopsia, horned dinosaurs. A claw i ...

I and II, and nearly complete ungual III of the right hand. Some of these remains were first described by Murakami et al. in 2008 as belonging to an indeterminate genus of

maniraptoran Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the non-avian dinosaurs that were more closely related to them than to '' Ornithomimus velox''. It contains the major subgroups Avialae, Dromaeosauridae, Troodontidae ...

theropod, possibly with therizinosauroid affinities. In 2022,

Kobayashi Kobayashi (Japanese language, Japanese: , 'small woods') is the 8th most common Japanese surname. A less common variant is . Notable people with the surname include: Arts Film, television, theater and music *, Japanese actress and voice a ...

et al. described ''Paralitherizinosaurus'' as a new genus and species of therizinosaurid making it the third therizinosaur found in Japan. This taxon represents the first named therizinosaur from Japan, with two other unnamed specimens being known. The generic name, "''Paralitherizinosaurus''", combines the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

words "paralos", meaning "tidal" and "therizo", meaning "scythe", and the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

"sauros", meaning "lizard". The specific name, "''japonicus''", refers to the taxon's discovery in Japan.

Classification

In their

phylogenetic analyses In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...

, Kobayashi et al. (2022) recovered ''Paralitherizinosaurus'' as a member of an unresolved

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

containing ''

Therizinosaurus ''Therizinosaurus'' (; meaning 'scythe lizard') is a genus of very large therizinosaurid dinosaurs that lived in Asia during the Late Cretaceous period in what is now the Nemegt Formation around 70 million years ago. It contains a single speci ...

'', ''

Suzhousaurus ''Suzhousaurus'' (meaning "Suzhou lizard") is a genus of large therizinosauroid dinosaur from the Early Cretaceous of China. The genus is known from two specimens discovered on the Xiagou Formation and Zhonggou Formation—which are situated in t ...

'', and an unnamed therizinosaurid from the

Bissekty Formation The Bissekty Formation (sometimes referred to as Bissekt) is a formation (geology), geologic formation and Lagerstätte which outcrop, crops out in the Kyzyl Kum desert of Uzbekistan, and dates to the Late Cretaceous Period (geology), Period. Laid ...

Uzbekistan , image_flag = Flag of Uzbekistan.svg , image_coat = Emblem of Uzbekistan.svg , symbol_type = Emblem of Uzbekistan, Emblem , national_anthem = "State Anthem of Uzbekistan, State Anthem of the Republ ...

. The

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below displays the results of their phylogenetic analyses. Similar results were recovered in an expanded version of this matrix in the 2025 description of ''

Duonychus ''Duonychus'' (meaning "two claws") is an extinct genus of therizinosaurid theropod dinosaurs that lived during the Late Cretaceous (Cenomanian to early Coniacian age) of what is now Mongolia. It is known from a partial skeleton, including sever ...

''.

References

External links

* {{Taxonbar, from=Q111821206 Therizinosauria Dinosaur genera Campanian dinosaurs Fossil taxa described in 2022 Dinosaurs of Japan