''Nemicolopterus'' is a dubious

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 ...

tapejaromorph Azhdarchoidea ( , meaning " azhdarchid-like forms") is a group of pterosaurs within the suborder Pterodactyloidea. Pterosaurs belonging to this group lived throughout the Early and Late Cretaceous periods, with one tentative member, '' Tendagur ...

pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earli ...

, based on a very small specimen described as the smallest known "adult" pterosaur to date. It lived in the

Jehol Biota The Jehol Biota includes all the living organisms – the ecosystem – of northeastern China between 133 and 120 million years ago. This is the Lower Cretaceous ecosystem which left fossils in the Yixian Formation and Jiufotang Formation. These d ...

120 million years ago.

Discovery and naming

The

generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

name "Nemicolopterus" comes from the following Ancient Greek words: "Nemos" meaning "forest", "ikolos" meaning "dweller", and "pteron" meaning "wing". The

specific Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the final ...

name ''crypticus'' is from "kryptos", meaning "hidden". Thus "''Nemicolopterus crypticus''" means "Hidden flying forest dweller".

Description

The type fossil specimen of ''N. crypticus'', catalog number IVPP V-14377, is housed in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China. The fossil was collected from the

Jiufotang Formation The Jiufotang Formation () is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms (see Jehol Biota). It is a member of the Jehol group. T ...

, which is of

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

age (120 mya). It was discovered in the Luzhhouou locality of Yaolugou Town, Jianchang County, Huludao City, western

Liaoning Province ) , image_skyline = , image_alt = , image_caption = Clockwise: Mukden Palace in Shenyang, Xinghai Square in Dalian, Dalian coast, Yalu River at Dandong , image_map = Liaoning in China (+all claims hatched).svg , ...

in northeastern

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It has a

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingsp ...

of slightly under 25 centimeters (10 in), making it smaller than all but a few specimens of hatchling pterosaurs. Wang et al. (2008), who originally described the specimen, concluded that it was immature, citing the amount of bone fusion and the

ossification Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in t ...

of the toes, gastralia, and sternum as indicating that it was a sub-adult rather than a hatchling. However,

Darren Naish Darren William Naish (born 26 September 1975) is a British vertebrate palaeontologist, author and science communicator. As a researcher, he is best known for his work describing and reevaluating dinosaurs and other Mesozoic reptiles, including ...

argued on his popular weblog that, due to the hypothesis that pterosaurs were highly

precocial Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

, bone fusion and ossification could have occurred very early in life, and that ''Nemicolopterus'' might in fact be a hatchling individual of the genus ''

Sinopterus ''Sinopterus'' (meaning "Chinese wing") is a genus of tapejarid pterodactyloid pterosaur from the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China. It was first described and named by Wang Xiaolin and Zhou Zhonghe. Hi ...

''. This identification was formally presented in 2021 study, which found that ''Nemicolopterus'' fit into a growth series as a young juvenile or hatchling ''Sinopterus''.

Classification

An analysis of pterosaur relationships by Andres and colleagues in 2014 found the specimen in a sister group relationship with "''Sinopterus''" ''gui''. A 2023 revision of ''Sinopterus'' concluded that it was impossible to assign the ''Nemicolopterus'' specimen to either ''Sinopterus'' or the new genus ''

Huaxiadraco ''Huaxiadraco'' (meaning "Huaxia, Hua Xia

hina Hina may refer to: People and deities * Hina (given name), including a list of people and fictional characters with the name * Hina (goddess), the name assigned to a number of Polynesian deities. * Hina (singer), of 2021 group Lightsum Other u ...

dragon") is a genus of Tapejaridae, tapejarid pterodactyloid pterosaur from the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, Chaoyang, Liaoning, China. It is the third va ...

'', and it was therefore considered an indeterminate sinopterine.

References

{{Portal bar, Paleontology, China Early Cretaceous pterosaurs of Asia Tapejaromorphs Fossil taxa described in 2008 Taxa named by Alexander Kellner Jiufotang fauna

Discovery and naming

Description

Classification

See also

References