A new lightfish, †Vinciguerria orientalis, sp. nov. (Teleostei, Stomiiformes, Phosichthyidae), from the middle Miocene of South Korea

A new fossil species of miniature lightfish, dagger Vinciguerria orientalis, sp. nov., is described from the middle Miocene beds of the Duho Formation, South Korea. This is the second extinct species of this genus described from skeletal remains. The new Neogene species is very similar to recent congeners in its general appearance, morphometrics, and body proportions. It is characterized by a combination of the following features: 37-40 vertebrae, 13-16 dorsal fin rays, 13-17 anal fin rays, 13-16 photophores in the ventral series from the pectoral fin base to the pelvic (ventral) fin base, 14 or 15 photophores in the ventral series from the anal fin base to caudal fin base of the ventral series, ca. 26 gill rakers, and a caudal body part length of more than 30% of standard length. The main difference separating dagger Vinciguerria orientalis from all other representatives of the genus is the lack of fusion between hypurals 1 and 2 and hypurals 3 and 4 and the separation of the urostylar centrum from hypural elements. This caudal skeleton structure appears to be a transition link between the Paleogene and Neogene-Recent species of this evolutionary lineage.