Quaternary vertebrate fauna of Bulgaria – composition, chronology and impoverishment

This study presents for the first time summarized data on 759 species/taxa (628 species at least) of six classes of Quaternary vertebrates of Bulgaria: Chondrichthyes (1); Actinopterygii (34); Amphibia (18); Reptilia (33); Aves (299); and Mammalia (374). The richest fauna has been recorded in the Late Pleistocene (285 species), followed by the Calabrian (255). Bulgaria has lost 32.3% of its former total Quaternary vertebrate fauna. The number of the lost taxa is as follows: species (245), genera (80), families (16), orders (5), of them three mammalian (Perissodactyla, Proboscidea, and Primates), and two avian (Otidiformes and Pteroclidiformes). Extinct families are: one amphibian (Palaeobatrachidae); two reptilian (Varanidae and Elapidae); three avian (Gruidae, Otididae, and Pteroclididae), and ten mammalian (Dipodidae, Eomyidae, Hystricidae, Ochotonidae, Hyaenidae, Phocidae, Equidae, Rhinocerotidae, Elephantidae, and Cercopithecidae). After the small mammals (mainly Cricetidae; 52 taxa), the composition of bovids (27 taxa) and canids (13 taxa) impoverished in a higher extent. The biggest number of recorded vertebrate families is found in the Meghalayan (79), followed by the Greenlandian (63) and the Late Pleistocene (62). At order and family levels, the most varied was the vertebrate fauna in the Meghalayan (39 orders, 79 families). In the Calabrian, the number of genera was a three times greater than in the Northgrippian, which indicates more diversified paleoenvironment. One genus, 25 species, and one subspecies have been described as new to the science from the Quaternary localities in Bulgaria