On a new species of Rhizodopsis from the Carboniferous of Scotland

Abstract

A new species of Rhizodopsis is described from material recovered from several Carboniferous locations within the Midland Valley of Scotland. Individual dermal skull bones were obtained from derelict coal waste tips at Wester Bracco, North Lanarkshire from shales originally overlying the Drumgray Coal. Individual dermal skull bones are well preserved, allowing for detailed description and reconstructions of the skull roof and cheek. Rhizodopsis rankini sp. nov. is distinguished by the presence of a lobed opercular, a deeply embayed postparietal shield between the supratemporal and tabular bones, and enlarged lateral extrascapulars. Rhizodopsis is here included in the Megalichthyidae, and an emended diagnosis of the family is given. The composition of the genus Rhizodopsis is reviewed. Except for Rhizodopsis hanbuchi , Rhizodopsis rankini and Rhizodopsis sauroides , all other species are based solely on scales. The validity of these scale-based species is reassessed and all but Rhizodopsis granulatus and Rhizodopsis mazonius are considered to be valid species. Thematic collection: This article is part of the Palaeontology of Scotland collection available at: https://www.lyellcollection.org/topic/collections/palaeontology-of-scotland