Taphonomic evidence of a Paleogene mammalian predator–prey interaction Katerina Vasileiadou a,b, ⁎ , Jerry J. Hooker a , Margaret E. Collinson b a Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5 BD, UK b Department of Geology, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK Received 9 December 2005; received in revised form 28 June 2006; accepted 3 July 2006 Abstract A taphonomic study has been undertaken on an assemblage of bones and teeth of Isoptychus sp. and Thalerimys fordi (extinct rodent family Theridomyidae) from a single bed in a coastal plain setting, in the Late Eocene (Priabonian) Osborne Member, Headon Hill Formation (Hampshire Basin, UK). The vertebrate fossils show good preservation and do not bear the marks of obvious long distance transport. The two theridomyid species show similar patterns of mortality, element representation and surface modifications, which indicate similar mechanisms of accumulation. There is high mortality of juvenile and old individuals indicating accumulation of the assemblage by the action of attritional not catastrophic agents. The postcranial elements show fragmentary states and very low relative abundances. The vast majority of elongate bones (limb bones, phalanges and metapodials) are broken and exhibit a spiral irregular type of fracture with rounded fracture edges indicating that the bones were broken when they were fresh and have subsequently undergone additional modification. The enamel of most of the cheek teeth and incisors shows localized etching to various degrees and most of the bones show etching. By elimination of other modifying agents the observed etching is attributed to digestive corrosion. Collectively, these data indicate that the majority of the theridomyid individuals were eaten and digested by an animal that could cause high fragmentation during ingestion and with stomach juices of relatively high acidity. Both these features characterize mammalian carnivores. The presence of puncture marks on bones of both theridomyid species and comparisons with sizes of bite marks caused by extant mammalian carnivores suggest predation by a small mammalian carnivore about the size of an arctic fox. The extinct amphicyonid carnivoran Cynodictis cf. lacustris occurs in the same bed and the sizes of some of its teeth match well with the sizes of the puncture marks on the theridomyid bones. A predator– prey interaction is, therefore, deduced for the amphicyonid and the two theridomyid species, thereby reconstructing a small part of the continental Paleogene food chain. © 2006 Elsevier B.V. All rights reserved. Keywords: Theridomyidae; Rodents; Carnivore; Eocene; Etching; Bite marks 1. Introduction Predator–prey relationships involving Paleogene mammals are generally not known. A noteworthy ex- ception is the established predator–prey relationship between crocodiles and the primate Europolemur at the Middle Eocene site of Messel, Germany (Franzen and Palaeogeography, Palaeoclimatology, Palaeoecology 243 (2007) 1 – 22 www.elsevier.com/locate/palaeo ⁎ Corresponding author. Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5 BD, UK. E-mail address: k.vasileiadou@nhm.ac.uk (K. Vasileiadou). 0031-0182/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2006.07.001