A historical overview of the reptile fauna from the Eocene Bolca Fossil-Lagerstätte (Italy)

The Eocene fossil reptiles from the Bolca Fossil-Lagerstätte (Verona, Italy) have been known in the literature since at least the 1850’ and were the subject of many studies during the second half of the XIX century and the first decades of the XX century. However, with the exception of a few papers, only rare works have been published on the Monte Bolca herpetofauna in recent years, and in many cases knowledge of the anatomy, taxonomy, and proper nomenclature of the Bolca reptiles still remains uncertain. Herein, we reassess the history of the discoveries, the earlier taxonomy and revisions of the crocodilians, turtles, and snakes from Bolca. To date, a total of 13 crocodilian specimens have been described in the literature or are housed in museum collections and remain unpublished. Two of the crocodilian specimens formerly cited and/or described are currently lost. All the fossil crocodilian specimens had originally been referred to two species, Crocodilus vicetinus Lioy, 1865, and Crocodilus bolcensis Sacco, 1895. In this study these identifications are considered invalid, and some specimens are referred to the genera Asiatosuchus, Boverisuchus, Diplocynodon and Hassiacosuchus while assignment at species level is still debatable. The turtles are represented by multiple specimens, which had been referred in the past to several different taxa of pleurodires and trionychids. However, only two species of turtles from Monte Bolca are currently accepted as being valid, both with species epithets dedicated to the renowned Italian palaeontologist Giovanni Capellini (1833-1922): the pleurodire Neochelys capellinii (de Zigno, 1890), which is the type species of its genus, and the trionychid “Trionyx” capellinii Negri, 1892. Both the crocodilians and the turtles had been collected at the Purga di Bolca locality. Only three snake specimens have been described from the Bolca area, representing also the oldest Cenozoic snakes from Italy: Coluber ombonii de Zigno, 1889 from Purga, and the archaeophiine Archaeophis proavus Massalongo, 1859 and anomalophiid Anomalophis bolcensis (Massalongo, 1859) from the Pesciara locality. The affinities of C. ombonii are still not clear, whereas A. proavus and A. bolcensis are considered valid and represent the type species of their genera but also are among the very few representatives of Archaeophiinae and Anomalophiidae respectively. The fossil reptiles from Bolca are housed in public collections in Italy (Turin, Verona, Padua, Rome, Pavia), the United Kingdom (London), USA (Pittsburgh, Cambridge), Germany (Darmstadt, Berlin) and Austria (Vienna).