''Jianghanichthys'' is an extinct genus of freshwater

cypriniform Cypriniformes is an order of ray-finned fish, which includes many families and genera of cyprinid ( carps and their kin) fish, such as barbs, loaches, botias, and minnows (among others). Cypriniformes is an "order-within-an-order", placed und ...

fish from the

Late Paleocene The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Serie ...

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

of central and southern China, and the only member of the family Jianghanichthyidae. It is the oldest cypriniform fish known from body fossils, and the most basal known cypriniform. The genus name ''Jianghanichthys'' derives from " Jianghan", the place where the first fossil remains of ''J. hubeiensis'' were found, and "ichthys" derives from the Greek word for 'fish'. It is also known as the "Chan Han fish" in the fossil trade.

Taxonomy

Two species are known, both of which were previously placed in ''

Osteochilus ''Osteochilus'' is a genus of freshwater ray-finned fish belonging to the family Cyprinidae, the family which includes the carps, barbs, minnows and related fishes. The fishes in this genus are mainly found in Southeast Asia with a few exten ...

:'' * ''J. hubeiensis'' (Lei, 1977) - Early Eocene (

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

) of

Hubei Hubei is a province of China, province in Central China. It has the List of Chinese provincial-level divisions by GDP, seventh-largest economy among Chinese provinces, the second-largest within Central China, and the third-largest among inland ...

, China ( Yangxi Formation) * ''J. sanshuiensis'' (Li & Wang, 1979) - Late Paleocene (

Thanetian The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Serie ...

) and Ypresian of

Guangdong ) means "wide" or "vast", and has been associated with the region since the creation of Guang Prefecture in AD 226. The name "''Guang''" ultimately came from Guangxin ( zh, labels=no, first=t, t= , s=广信), an outpost established in Han dynasty ...

, China ( Buxin Formation) (=''Osteochilus laticorpus'' Li & Wang, 1979, ''O. longipinnatus'' Li & Wang, 1979) There are still disagreements as to the scientific classification, name and age of this genus. However the body shape of ''Jianghanichthys ''differs from that of all '' Amyzon'' species. ''J. hubeiensis'' was reclassified from ''Osteochilus'' into the new genus ''Jianghanichthys'' in 1987, and in 2015 it was moved from the

Catostomidae The Catostomidae are the suckers of the order (biology), order Cypriniformes, with about 78 species in this family (biology), family of freshwater fishes. The Catostomidae are almost exclusively native to North America. The only exceptions are ' ...

to the new, basal family Jianghanichthyidae. In 2024, the slightly older species ''J. sanshuiensis'' was also reclassified into this genus from ''Osteochilus'', marking both a slight temporal extension and a range extension for the genus.

Distribution

These fishes lived in the early

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

period. Fossils of ''Jianghanichthys'' have been found in

and

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 ...

. Fossils of ''J. hubeiensis'' are quite common and can be found in most shops. Most of these are among the thousands of well-preserved ''J. hubeiensis'' fossils which were discovered in an outcrop in a farm near

Songzi Songzi () is a city in the southwest of Hubei province, People's Republic of China, located in the middle reach and southern bank of the Yangtze River. It is a county-level city under the administration of the prefecture-level city of Jingzhou, a ...

in the 1980s. However, overcollection by commercial fossil collectors had destroyed this locality by 2005, though some new specimens have since been discovered with later fieldwork.

References

Organism Names

Enciclopaedia of Life
* Fish, Reptilia & Mammalia. Biostratigraphy of the Yangtze Gorge area. Volume 5. Cretaceous and Tertiary., Geological Publishing House, Beijing, 1987: 133–187. Chapter pagination: 187–200. Zoological Record Volume 127 * Juan Liu, Mee-mann Chan
A new Eocene catostomid (Teleostei: Cypriniformes) from northeastern China and early divergence of Catostomidae

Universal Biological Indexer
* LIU Juan, TSENG Zhijie J., WILSON Mark V., MURRAY Alison M.
ASIAN FOSSIL CATOSTOMIDS AND ONTOGENETC CHANGE IN EARLY CYPRINIFORMS
;Specific Cypriniformes Prehistoric ray-finned fish genera Paleogene fish of Asia Fossils of China Thanetian genus first appearances Ypresian extinctions Fossil taxa described in 1987 {{paleo-rayfinned-fish-stub