Ponerosteus

Ponerosteus is a dubious genus of extinct archosauromorph from the Late Cretaceous (Cenomanian-aged) Korycanar Formation of the Czech Republic that was initially identified as a species of the dinosaur Iguanodon.^[1]

Ponerosteus Temporal range: Upper Cretaceous, Cenomanian PreꞒ Ꞓ O S D C P T J K Pg N
Holotype tibia of P. exogyrarum (National Museum in Prague)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Genus:	†Ponerosteus Olshevsky, 2000
Species:	†P. exogyrarum
Binomial name
†Ponerosteus exogyrarum (Fritsch, 1878)
Synonyms
Iguanodon exogirarum Fritsch, 1878 Iguanodon exogyrarum (Fritsch, 1878) vide Chure & McIntosh, 1989 Iguanodon exogirarus Brinkmann, 1988 Procerosaurus Fritch, 1905 (preocccupied) Procerosaurus exogirarum Brinkmann, 1988 Procerosaurus exogirarus Brinkmann, 1988

The type, and currently only, species is P. exogyrarum.^[2]

Discovery and naming

The holotype, NAMU Ob 40, consisting solely of an internal cast of a tibia, was discovered near Holubice, Kralupy nad Vltavou, and was first identified as a dinosaur, which was named "Iguanodon exogirarum" (later "Iguanodon exogyrarum") by Antonín Frič in 1878.^[1][3] He later (1905) renamed it Procerosaurus,^[4] unaware that this name was already in use (von Huene, 1902^[5]) for what is now a synonym of Tanystropheus. NAMU Ob 40 was renamed Ponerosteus exogyrarum (species name amended) by George Olshevsky in 2000, and Olshevsky considered Ponerosteus to be a nomen dubium;^[2] the holotype has since been put on display at the National Museum in Prague.^[2]

The name Ponerosteus can be translated as "bad", "worthless", or "useless bone", which describes the fragmentary nature of the holotype.^[6]

Classification

Although initially identified as being a dinosaur belonging to the genus Iguanodon,^[1] Ponerosteus is currently classified within Archosauromorpha.^[2]