Finds of fragmentary bird skeletons in the Middle Miocene of the northern Caucasus

Resumo

The first anatomically assembled skeletal remains of Neogene birds in Russia have been found. The head and a fragment of the vertebral column of a duck (Anatidae) and a hind limb of a perching bird (Passeriformes) from the Middle Miocene of the Krasnodar Region (Tsurevsky Formation) comprise the earliest known Miocene birds from European Russia. The skull of a very small duck (smaller than any extant species of Eurasian ducks) shows a combination of morphological characters characteristic of the extant species of Tadorna and Nettapus, and could belong to a representative of the fossil genus Mioquerquedula. This discovery supports a separate generic status for small-sized middle Miocene anatids from Eurasia, and suggests that they were more primitive than the extant Anatinae.