1. Ablepharus kitaibelii fitzingeri Mertens, 1952 and Ablepharus pannonicus (Lichtenstein, 1823)

Leopold Fitzinger described Ablepharus pannonicus as a new species in 1824. In the description Fitzinger notes that Carl v. Schreibers had received two living animals from Professor Kitaibel named as “ Lacerta nitida ” together with a short description and a “very mediocre” picture as early as 1813. Fitzinger did not mention the location data in his introductory text but later in the detailed description. Professor Kitaibel had already died when the shipment arrived in Vienna. At that time (1806–1851), Carl von Schreibers headed the “Vereinigten k.k. Naturalien-Cabinete”, the predecessor of the Natural History Museum Vienna (NMW). Fitzinger saw himself unable to provide a detailed description of these lizards (because of the short description and the very poor picture) until he received a message from Joseph Sadler, the curator of the Natural History Cabinet of the Royal National Museum in Pesth. Because of this information, he was now able to examine the specimens in detail and to provide a good illustration of the species. It remains open whether Fitzinger received further specimens from Sadler or (only) further information. It is also unclear if Fitzinger got the terra typica data from Professor Kitaibel (via Schreibers) or from Mr. Sadler. In any case, it should take 11 more years to describe this scincid species from Hungary in detail. The generic name “ Ablepharus ” was also introduced in his description for the first time (Fitzinger, 1824). Therefore, Ablepharus pannonicus Fitzinger, 1824 is the type of the genus Ablepharus. The species description is based only on a single specimen. Place of collection—and the terra typica—is Osen at Lake Balaton. This specimen must therefore be considered as the holotype, but unfortunately cannot be found in the collection of the NMW, which has not been registered in the “Katalog der Typen der Herpetologischen Sammlung des Naturhistorischen Museums Wien” (Gemel et al. 2019) and “Supplementa & Errata zum Katalog der Typen der Herpetologischen Sammlung des Naturhistorischen Museums Wien” (Ernst et al. 2020). Actually, Lichtenstein had already described Scincus pannonicus in 1823, a new species from “Bucharei” (= Buxoro, in the German name Buhara, city and province of the same name in Uzbekistan) from the collection of Eduard Eversmann in 1821. But this species is different from the Southeast European form of the Snake-еyed Skink that Fitzinger intended to describe. Lichtenstein (1823: 145) already knew Fitzinger’s description and assumed that it was the same species as Scincus pannonicus, which is why he mentioned “ Ablepharus pannonicus Fitz. ” as a synonym in his description. In his Scincus pannonicus description, Lichtenstein only referred to the material from the Bucharei collected by Eversmann. Therefore, Fitzinger’s name from 1823 is a nomen nudum, since there was no valid description of Fitzinger yet and it was published in 1824 (ICZN: Art. 12.1.). Since Ablepharus pannonicus (Lichtenstein, 1823) is the Asian Snake-еyed Skink, this name must replace Ablepharus brandtii Strauch, 1868 as an older name.

The European Snake-eyed Skink is described with its present scientific name Ablepharis [sic] kitaibelii for first time by Bibron & Bory (1833) from the vicinity of Pilos, Peoloponnese, Greece. Therefore, Ablepharis kitaibelii is the synonym of Ablepharus kitaibelii kitaibelii (Bibron & Bory de Saint-Vincent, 1833) —the southern population of this species’ range. The holotype of the taxon is preserved in the Muséum national d’histoire naturelle, Paris, France, cat. No. MNHN- RA 5392. Ablepharus kitaibelii stepaneki is described later by Fuhn (1970) from Romania (the holotype is preserved in Grigore Antipa National Museum of Natural History, Bucurest, cat. No. 150).

According to Štepánek (1938, 1944) the correct name of the species should be Ablepharus pannonicus Fitzinger 1924, until in 1952, Mertens created a nomen novum for the Snake-eyed Skink from Hungary with “ Ablepharus kitaibelii fitzingeri ”, which had to take the place instead of Ablepharus pannonicus Fitzinger, 1824 because of the above-mentioned reasons. Mertens (1952) explained the circumstances in detail and defined the name later in the list of European amphibians and reptiles (Mertens & Wermuth 1960) as follows:

Ablepharus kitaibelii fitzingeri Mertens 1952: nomen novum pro Ablepharus pannonicus Fitzinger, 1824 with distribution in the Czech Republic, Slovakia, Hungary, Romania, Bulgaria and “ Yugoslavia ”.

Accordingly, the valid name for the Asian Snake-eyed Skink is Ablepharus pannonicus (Lichtenstein, 1823), while Ablepharus pannonicus Fitzinger, 1824 is a different species, now known as Ablepharus kitaibelii fitzingeri Mertens, 1952 (nom. nov. pro Ablepharus pannonicus Fitzinger, 1824).

The explanations of Mertens (1952) have received too little attention to this day, although he has given all the arguments for this by rejecting Štepánek’s objections (Štepánek 1938, 1944). Incorrect information can be found in several sources of recent literature (see e.g. Fuhn 1969; Poulakakis et al. 2005; Karamiani 2017; Zimić et al. 2018; Uetz et al. 2020). This may be the reason for the wrong interpretation that the taxon under “ Ablepharus pannonicus (Fitzinger, 1824) ” is a synonym of Scincus pannonicus Fitzinger in Lichtenstein 1823: 145 (nomen nudum), although a nomen nudum cannot be a synonym.