New Crassigyrinus-like fibula from the Tournaisian (earliest Carboniferous) of Nova Scotia

The transition between the Devonian and Carboniferous is important for tetrapod vertebrates. By the end of the Devonian the first limbs are present in aquatic animals, and by the mid Carboniferous fully terrestrial tetrapods have diversified. Knowledge of the fin-to-limb transition is sparse because few fossils from the earliest Carboniferous (Tournaisian) are known. Blue Beach Nova Scotia, in addition to a small number of sites in Scotland and Australia, is an exception to this global trend. Previous reports from Blue Beach identified fossils from a variety of Devonian-like and Carboniferous-like tetrapod body forms, making it a valuable site for studying the fin-to-limb transition. Here we report on a new left fibula from Blue Beach, which we attribute to the later occurring Visean-aged (early Carboniferous) Crassigyrinidae. Recent investigations of deposits in Scotland, similar in age to the Tournaisian exposed at Blue Beach, have found Crassigyrinus-like elements as well, reinforcing this 20-million-year lineage extension.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author