Article: Micro-ornamentation of some spiriferide brachiopods

The use of the term microspine by Balinski (1975) for a variety of structures on several taxa of spiriferides is discussed and, in part, rejected. Balinski described two distinct structures; true microspines and a papillose ornamentation resulting from external shell erosion. Evidence for a microspinose ornamentation on species of Crurithyris is presented together with models distinguishing the growth of spines in spiriferides from that in productaceans.