A multivariate taxonomic analysis of the Late Carboniferous vertebrate ichnofauna of Alveley, southern Shropshire, England

Abstract

A diverse Late Carboniferous (Westphalian D; Moscovian) vertebrate ichnofaunal assemblage from the Alveley Member (Salop Formation, Warwickshire Group) of Alveley, southern Shropshire, UK, is a significant example of an early, transitional tetrapod community. Positive tetrapod footprint casts (convex hyporeliefs) within fine‐ and medium‐grained sandstone red‐beds were formed subaqueously in an alluvial floodplain setting. A statistical analysis of this material, the first using multivariate techniques on Late Palaeozoic trackways, has been undertaken to determine the ichnospecific diversity and morphological variation within the ichno‐assemblage. Nine ichnotaxa have been identified, following a study of more than 200 trackways. These include the amniote ichnogenera Dimetropus Romer and Price, 1940, Ichniotherium Pohlig, 1885 and Hyloidichnus Gilmore, 1927, but there is a dominance of trackways of the ichnogenus Limnopus Marsh, 1894, which represent stem‐lissamphibian ‘temnospondyls’. Following statistical analysis, the ichnogenera Limnopus and Batrachichnus are subsumed as ichnosubgenera under the senior available name Limnopus. The Alveley ichnofaunal assemblage provides significant range extensions for a number of amniote and stem‐lissamphibian trackmakers from the latest Carboniferous or Permian down into the mid‐Late Carboniferous. It also marks a key transitional stage in the evolution of tetrapod communities, from the ‘amphibian’ grade assemblages of the Carboniferous to the more terrestrial, amniote‐dominated communities of the Early Permian.