EXOSKELETON STRUCTURE AND THE DISTRIBUTION OF AESTIASPIS VIITAENSIS (AGNATHA) FROM THE SILURIAN OF ESTONIA

Abstract

The exoskeleton of one of the earliest osteostracans, Aestiaspis viitaensis Janvier et Lelievre, 1994, from the Silurian of Saaremaa Island (Estonia) was studied using a scanning electron microscope. On the basis of the study of exoskeleton fragments by dissolving samples from different sites and their comparison with the holotype exoskeleton, it is concluded that the members of the genus Aestiaspis are distributed in the Viita and Vesiku Beds of the Rootsiküla Regional Stage and, probably, Kuusnymme Beds of the Rootsiküla Regional Stage and Himmiste Beds of the Paadla Regional Stage.