Sedimentation of the Himmiste-Kuigu fish bed (Ludlow of Estonia) and taphonomy of the Phlebolepis elegans Pander (Thelodonti) shoal

Abstract

Sediments with the squamations of Phlebolepis elegans Pander at Himmiste-Kuigu were formed in a lagoon of the Palaeobaltic Sea, situated in the tropical realm during Himmiste time of the Paadla Age, Ludlow, late Silurian. From the micro- and macrolithological features of the rocks, and the distribution of facies during Himmiste time it is concluded that the thelodonts died in a shallow depression on the bottom of the lagoon behind the reef belt towards the land; the depression acted as a trap during low tide. Unfavourable conditions, primarily the lack of oxygen in warm and shallow water, caused the perishing of the Phlebolepis shoal. Very low wave activity prevented postmortem disintegration of the squamation and rapid conservation in mud saved the exoskeletons from scattering.