MS. HERMIONE BECKETT (Orcid ID : 0000-0003-4475-021X) DR. ZERINA JOHANSON (Orcid ID : 0000-0002-8444-6776) Article type : Original Article Handling Editor: Lionel Cavin Running head: Relationships of London Clay trichiuroids Hermione Becketta,b, Sam Gilesa, Zerina Johansonb and Matt Friedmana,c aDepartment of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK bDepartment of Earth Sciences, Natural History Museum, London, SW7 5BD, UK cCurrent address: Museum of Paleontology and Department of Earth and Environmental Sciences, University of Michigan, 1109 Geddes Ave, Ann Arbor, MI 48109-1079, USA *Correspondence to: Hermione Beckett, +44 (0) 1865 272000
[email protected], Department of Earth Sciences, University of Oxford, Oxford, UK, OX1 3AN Short title: Relationships of London Clay trichiuroids Author Manuscript Key words: Trichiuroidea, morphology, London Clay, Trichiuridae, Gempylidae, fossil This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/spp2.1221 This article is protected by copyright. All rights reserved A ‘Gempylids’ (snake mackerels) and trichiurids (cutlassfishes) are pelagic fishes characterised by slender to eel-like bodies, deep-sea predatory ecologies, and large fang-like teeth. Several hypotheses of relationships between these groups have been proposed, but a consensus remains elusive. Fossils attributed to ‘gempylids’ and trichiurids consist almost exclusively of highly compressed body fossils and isolated teeth and otoliths. We use micro-computed tomography to redescribe two three- dimensional crania, historically assigned to †Eutrichiurides winkleri and †Progempylus edwardsi, as well as an isolated braincase (NHMUK PV OR 41318).