Pshekhagnathus

Pshekhagnathus polypterus is an extinct genus of pipefish known from the Lower Oligocene of the North Caucasus, Russia.

 Description 
The body was elongated, encased in a series of bony rings. The tail was not prehensile. The fish's body was probably not laterally compressed, since no one of the available specimens is exposed in perfect lateral view. However, this preservation makes it quite hard to identify the exact lateral pattern of ridge configuration.

The caudal fin is relatively small and consists of ten soft rays. The middle caudal-fin rays are longer than the outer ones. The structure of the caudal skeleton is not recognizable because it is hidden under dermal armor. The opercle is large and is sculptured by pits arranged in multiple rows.

Other living and fossil pipefish known have a very small anal fin with two to six rays, but this fish had a fully developed anal fin almost identical to its opposite dorsal fin. This feature led to the creation of a pipefish subfamily, the Pshekhagnathinae, to accommodate this Oligocene creature.

 Related pages 

 Karpinskiprion
 Kenyaichthys

 References 

Category:Syngnathiformes
Category:Extinct fish
Category:Ray-finned fish
Category:Oligocene
Category:Russia