The Pironaea species (Bivalvia: Hippuritidae), other than P. milovanovici Kühn, from SE Spain, E Serbia and E and SE Anatolia, and a revision of the genus Pironaea from the Upper Cretaceous of Eurasia

Multiple-fold hippuritid rudist bivalves –those having infolds of the outer shell layer into the inner shell layer (secondary pillars or rays) other than the three hippuritid pillars– from Eurasia have been referred to genus Pironaea Meneghini. The characters considered in taxonomy caused a somewhat confusing large number of Pironaea species in literature. The study of new material from SE Spain, E Serbia and E and SE Anatolia, stressing the taxonomic relevance of the ontogenetic and intraspecific variability, as well as published material from these or other areas, has resulted in reducing the number of species to three, besides P. milovanovici Kühn. Thus, a clearer and simpler taxonomic framework of Pironaea species, and their evolutionary relationship, is proposed. P. polystyla (Pirona) is recognized in N and S Italy, Slovenia, Croatia, E and W Serbia, W Bulgaria, Turkey, and UAE, including as junior synonyms P. anatolica Karacabey, P. buseri Pejović, P. dalmatinica Milovanović, P. dinarica Milovanović, P. fruscagorensis Milovanović, Sladić-Trifunović, Grubić, P. lisansis Pamouktchiev, P. machnitschi Wiontzek, P. praeslavonica Milovanović, Sladić-Trifunović, Grubić, P. sladici Pamouktchiev, and P. slavonica Hilber. P. corrugata (Woodward) is only recognized in E and SE Anatolia and not considered the primitive ancestor of the other species. P. transitoria Milovanović is recognized in SE Spain, N Italy, E and W Serbia, W Bulgaria, NW Turkey, and Tunisia and includes as junior synonyms P. branislavi Sladić-Trifunović, P. corrugata nicklesi Philip, P. garlensis Pamouktchiev, P. negrichorensis Pamouktchiev, P. pejovici Pamouktchiev, P. praeyaroslavensis Pamouktchiev, P. timacensis Milovanović, P. udinensis Pamouktchiev, and P. yaroslavensis Pamouktchiev.