A statistical study of Rhamphorhynchus from the Solnhofen Limestone of Germany: Year-classes of a single large species

Abstract

A statistical and morphological study of the pterosaur Rhamphorhynchus from the Solnhofen Limestone of Germany shows that specimens fall into discrete size-classes that are year-classes resulting from seasonal mortality or preservation of specimens. Taxonomic characters used in the past to separate species of Rhamphorhynchus are all related to size and ontogeny, and all specimens belong to a single species, R. muensteri. Thus, the collections of Rhamphorhynchus provide an unequaled record of the growth and development of a Jurassic rhamphorhynchoid pterosaur. Rhamphorhynchus did not have rapid determinate growth; the growth rate was comparable to that of extant crocodilians, and growth continued over the course of at least three years after individuals began to fly.