Species distribution and differentiation of Eurasian Hypolagus (Lagomorpha: Leporidae)

Features of p3 (width, length, AER and PER deepth, and AER-factor and PER-factor), as well as of mandible (diastema length, lower tooth row length, and mandible height) of five Eurasian Hypolagus species were analysed. The "beremendensis-igromovi" morphological group is distinguished on the basis of similar dimensions and proportions of mandible and teeth. The Pleistocene Central European populations of Hypolagus beremendensis, characterised by larger dimensions, resemble Hypolagus igromovi (Don Region). The division of Hypolagus beremendensis into two, previously proposed, subspecies is maintained. H. beremendensis beremendensis existed from Late Ruscinian to Late Villányian and H. beremendensis brachygnathus was known from Late Villányian to Steinheimian (Q3). Similarity between Hypolagus b. brachygnathus resemble Hypolagus igromovi could be the result of either parallel evolution or closer relationships. Thus, it is possible that the significantly larger, Late Villányian and Early Pleistocene populations of Hypolagus beremendensis are the descendants of Hypolagus igromovi, which invaded Central Europe in the Villányian. Hypolagus schreuderae, described from the Nihewanian deposits, is characterised by a long diastema, a simple enamel pattern and forms a distinct species.