Published online by Cambridge University Press: 14 July 2015
The genus Salopina Boucot (in Boucot et al., 1960) is now widely recognized in Silurian to Middle Devonian rocks (Walmsley et al., 1969); its Ludlovian type species is S. lunata J. de C. Sowerby (Walmsley, 1965). From the outset, a variety of morphs and named species have been gathered within the genus Salopina, although some significant differences have been evident. The most obvious difference is size, which is often ignored as a consequence only of ontogenetic variation. Size can also be a hallmark of habitat, or biofacies, or position in the benthic community chain.