New information on the Early Devonian acanthodian Mesacanthus mitchelli from the Midland Valley of Scotland
The Palaeozoic genus Psephodus (Chondrichthyes, Cochliodontiformes) and the transition from teeth to tooth plates in holocephalians
Desiccation cracks in Middle Devonian rhythmic lacustrine sediments of Rousay Flagstone, West Kirbest, island of Westray, Orkney. The mud cracks here represent a temporary dry period within a lake bed where polygons are 25 – 30cm across and crack infills have been dolomitized, providing a colour contrast, enhanced by the presence of microbialites. Image courtesy of Dr David Leather, reproduced with permission.