Corydoras revelatus is an extinct species of callichthyid

Callichthyidae

Callichthyidae is a family of catfishes , called armored catfishes due to the two rows of bony plates running down the length of the body. This family contains some of the most popular freshwater aquarium fish, such as the Corydoras.-Taxonomy:The family derives its name from the Greek words kallis...

 known from a single specimen found in Late Paleocene

Paleocene

The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

 strata of the Mais Gordo Formation in Salta

Salta

Salta is a city in northwestern Argentina and the capital city of the Salta Province. Along with its metropolitan area, it has a population of 464,678 inhabitants as of the , making it Argentina's eighth largest city.-Overview:...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. According to chronological dating of the strata, the fossil specimen is about 58.2–58.5 million years old.

Compared to modern species, C. revelatus has a short, comparatively rounded head, and rather low-set eyes. Although the species's position within the genus Corydoras

Corydoras

Members of the South American Corydoras genus are freshwater temperate and tropical catfish in the armored catfish family , and are commonly referred to as corydorases, cories, or cory catfish.-Taxonomy:...

is tentative and unresolved, its anatomy confirms that it is a member of the subfamily, Corydoradinae, and demonstrates that the callichthyids had already diverging or diversifying before the end of the Paleocene.