Systematic reassessment of Edaphodon eyrensis Long, 1985 (Holocephali, Chimaeroidei) from the Early Cretaceous of South Australia

ABSTRACT

A chimaeroid species, Edaphodon eyrensis Long, 1985 (Holocephali, Chimaeroidei), from the Lower Cretaceous Bulldog Shale of the Eromanga Basin, South Australia, is reassessed as Ptyktoptychion eyrensis (Long, 1985), comb. nov. This is the oldest representative of the endemic Australian chimaeroid genus Ptyktoptychion Lees, 1986. An ancestor of this genus could be the Early Cretaceous chimaeroid Ischyodus thurmanni Pictet and Campiche, 1858 from the northern hemisphere. Ptyktoptychion eyrensis survived in Australia in southern polar environment conditions.

ACKNOWLEDGMENTS

Sincere thanks to B. McHenry (SAM, Adelaide) for scientific loan of the Holotype SAM P24770 to the Museum of Victoria and to the late D. Pickering (VM, Melbourne) for access provided to the loaned specimen and hospitality during my short stay in Melbourne in 2010. The following persons are kindly acknowledged for the opportunity to study chimaeroid comparative material under their care in 2007 and 2011: Z. Johanson (NHMUK), M. Howe and L. Neep (BGS), A. Cook and K. Spring (QMF). J. Pollerspöck and the “Shark-references” web-project (Pollerspöck and Straube, 2019) are thanked for permanent access to rare chondrichthyan publications. I thank D. J. Ward (NHMUK) for primarily correcting English and scientific editing of an early draft of the manuscript. D. Cicimurri and S. Gouiric-Cavalli provided careful reviews, and editors J. Kriwet and J. Harris provided helpful comments; I am grateful for all their suggestions for improvement to the manuscript. The research was supported by grants no. 10–05–00927–a and 18–05–01045–a of the Russian Foundation for Basic Research (RFBR), and by the Kazan Federal University Strategic Academic Leadership Program.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.