New allotherian specimens from the Middle Jurassic Woodeaton Quarry (Oxfordshire) and implications for haramiyidan diversity and phylogeny

Abstract

We report new allotherian tooth specimens from the Middle Jurassic White Limestone Formation at Woodeaton Quarry (Oxfordshire), United Kingdom. Two teeth are assigned to Kermackodon (=Eleutherodon) oxfordensis, a taxon whose original generic name (Eleutherodon) was preoccupied and is here assigned to Kermackodon to form a new binomial combination for the species name. Butlerodon quadratus gen. et sp. nov. (family Kermackodontidae), based on 13 cheek teeth and incisors, shows dental features intermediate between K. oxfordensis and the Late Triassic “haramiyidans” (Haramiyavia and Thomasia). Woodeatonia parva gen. et sp. nov. (family indeterminate), based on three teeth, is characterized by its small size. A second upper molar from a multituberculate is identified as Hahnotherium cf. H. antiquum, which possesses characters typical for multituberculates but distinctive from “haramiyidans”. The allotherian teeth from the Forest Marble Formation, previously assigned to the haramiyidans “Eleutherodon”, “Millsodon” and “Kirtlingtonia”, and the multituberculate Kermackodon, are reinterpreted as teeth from different upper or lower dental loci of the same haramiyidan species K. oxfordensis, which result in significant taxonomical modification of these allotherians (“haramiyidans” and multituberculates). Given that Kermackodon has been regarded as a transitional form between multituberculates and “haramiyidans”, these taxonomical modifications would affect interpretation of early evolution of allotherians. In a comparison of molars in known “haramiyidans”, we delve into their occlusal patterns and cusp homologies that have been controversial but pivotal for understanding evolution of allotherians. We further conduct the first phylogenetic analysis of haramiyidan species. The European Late Triassic species form the stem-ward taxa of “haramiyidans” and the Jurassic species from the United Kingdom are grouped with arboroharamiyids from the Yanliao Biota, China, and nested in “haramiyidans”.

http://zoobank.org/urn:lsid:zoobank.org:pub:38F1FB5A-17A2-498F-B1FD-38D975548201

http://zoobank.org/urn:lsid:zoobank.org:act:FF5ADA10-C044-4541-ADA6-54448F17C673

http://zoobank.org/urn:lsid:zoobank.org:act:6E59071A-56DF-43D2-A140-2860465BFECA

http://zoobank.org/urn:lsid:zoobank.org:act:CA2EE3CF-951C-450A-879D-2AE438F6BB2A

http://zoobank.org/urn:lsid:zoobank.org:act:6B26D9C3-9FC3-4517-A1EF-51822067F970

Keywords:

• allotherians
• haramiyidans
• multituberculates
• phylogeny
• Middle Jurassic
• Woodeaton Quarry

Acknowledgements

Excavation, processing, and curation of the Woodeaton specimens were led by David Ward, Emma Bernard, Simon Wills and Pip Brewer and possible due to financial support provided by the Natural History Museum, London, UK, Collections Committee Acquisitions Fund and Earth Sciences Department Investment Fund. Acquisition of the specimens was possible due to the kindness of Michael McKenna and access to the site was provided by Michael McKenna and Brian Henman. Thank you also to everyone involved in the Woodeaton project including the numerous volunteers. We thank G. Billet and E. Gheerbrant (Museum national d’Histoire naturelle, Paris, France) and B. Lindow (Natural History Museum of Denmark, University of Copenhagen, Denmark) for access to specimens under their curatorial care. Mike Day assisted with access to specimens. Svetlana Nikolaeva and Max Barclay provided advice on interpreting the ICZN. F.Y. Morgan Hill Chase and Andrew K. Smith (American Museum of Natural History) are thanked for CT scanning. Alex Ball and Tomasz Goral (Natural History Museum, London, UK) and Xiaomin Wang (Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences) are thanked for SEM imaging of the specimens. We thank A. Averianov (Zoological Institute, Russian Academy of Sciences) and T. Martin (Section Palaeontology, Institute of Geosciences, Rheinische Friedrich-Wilhelms-Universität Bonn) for helpful and constructive comments and A. Averianov for sharing photographs of specimens. Mao was supported by the National Natural Science Foundation of China (42122010; 41404022; 41688103), the Youth Innovation Promotion Association CAS (2019076), and the Kalbfleisch Fellowship, Richard Gilder Graduate School, American Museum of Natural History.

Supplemental material

Supplemental material for this article can be accessed here: http://dx.doi.org/10.1080/14772019.2022.2097021.

Associate Editor: Alistair Evans