A new pupilloid species and some other Eocene terrestrial gastropods from Baltic amber

摘要

Though snails are only rarely embedded in amber, snail inclusions are known from amber of different ages, originating from various continents, including Baltic amber. Some such snail species were described as early as the end of the 19th c., but most snail inclusions in the Baltic amber were identified relatively recently. The record indicates that among snails, the pupilloids are the best preserved in amber. This may result from their small size and the shell structure, most often reinforced with apertural barriers. In this paper, besides pupilloids of the genera Leiostyla and Propupa (both presented earlier), we describe a new species Ptychalaea mystica and discuss the position of Ptychalaea within the Pupilloidea. Furthermore, the finding of a Hydrocena species significantly extends the stratigraphic range of this genus as far back as the Eocene.