The original generic name of this frog was Cordicephalus Nevo (1968); however, this generic name turned out to be preoccupied by a cestode genus Cordicephalus Wardle, McLeod & Stewart (1947), which remains nomenclaturally available in spite of being considered a junior synonym of the diphyllobothriid genus Pyramicocephalus.

[2] Fossils of N. gracilis were found in a lacustrine deposit in Makhtesh Ramon called "Amphibian Hill" and it is believed they lived during the Lower Cretaceous.

[3] When first described by Eviatar Nevo of the University of Haifa[4] (in 1968) the genus Cordicephalus was thought to contain two species, C. gracilis and C.

[6] The replacement generic name is derived from the surname of Eviatar Nevo and from batrachus, a Greek word for a frog.

Other features that support that view that N. gracilis had a mainly aquatic lifestyle is its short axial column as well as large foot bones which may imply extensive webbing.