A STATISTICAL STUDY OF RHAMPHORHYNCHUS FROM THE SOUTHERN LIMESTONE OFGERMANY - YEAR-CLASSES OF A SINGLE LARGE SPECIES

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