Sedimentology, fauna, and taphonomy of the Pavâri site, Late Devonian of Latvia

The distribution, sorting, orientation, state of preservation, and wearing of vertebrate remains from the upper Famennian (Upper Devonian) Ketleri Formation of the Pavâri site, western Latvia, have been studied. The vertebrate fauna is dominated by the placoderm, Bothriolepis ciecere, and includes also acanthodians, several sarcopterygian taxa and the primitive tetrapod Ventastega curonica. Taxonomic composition, pattern of distribution, sorting, preferred orientation of vertebrate remains suggest that the assemblage was winnowed by water transport in a low concentration flow. Nevertheless, an almost total lack of wearing and the high degree of preservation, including many articulated skeletal parts, indicate short transportation of the remains before burial. An almost autochtonous character of the oryctocoenosis is, therefore, suggested. Sedimentological and taphonomic studies of the locality suggest that it was formed in relatively shallow sea conditions dominated by stream and weak wave influence, probably representing a low-tidal near-shore depositional environment. Most likely, vertebrates from the Ketleri Formation dwelled in a marine coastal environment, although the possibility that the remains have been transported for a considerable distance can not be excluded.