• A study of the body sizes of
Devonian and
Carboniferous vertebrates (jawless vertebrates, placoderms, acanthodians, cartilaginous fishes,
ray-finned fishes and
sarcopterygians, including
tetrapods) is published by
Sallan & Galimberti (2015), who conclude that following the
Hangenberg event the majority of vertebrate lineages experienced persistent reductions in body size for at least 36 million years, and that the few large-bodied survivors of the Hangenberg event failed to diversify, while small-bodied survivors gave rise to all subsequent vertebrate lineages. • A study on the skull anatomy of
Acanthodes and its implications for inferring the phylogenetic placement of
acanthodians is published by Brazeau & de Winter (2015). • A study on the fossil specimens considered to be either decomposed or immature specimens of
Triazeugacanthus affinis is published by Chevrinais, Cloutier & Sire (2015), who reinterpret the variation initially thought to be caused by various degrees of decomposition as corresponding to
ontogenetic changes. • A study on the development of saw-teeth in the
Cretaceous ray
Schizorhiza stromeri is published by Smith
et al. (2015). • Three large
mackerel shark vertebrae, interpreted as belonging to a single individual with a calculated total body length of 6.3 m, are described from the
Lower Cretaceous Duck Creek Formation (
Texas,
United States) by Frederickson, Schaefer & Doucette-Frederickson (2015). ==New taxa==