OSTRICH 2011, 82(1): 57–63 Printed in South Africa — All rights reserved Copyright © NISC (Pty) Ltd OSTRICH ISSN 0030–6525 EISSN 1727–947X doi: 10.2989/00306525.2011.561526 Ostrich is co-published by NISC (Pty) Ltd and Taylor & Francis Introduction A chat (Saxicolinae, Muscicapidae) from the mid-Holocene of Florisbad, South Africa Albrecht Manegold 1 * and James S Brink 2 1 Forschungsinstitut Senckenberg, Sektion Ornithologie, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany 2 Florisbad Quaternary Research, National Museum, PO Box 266, Bloemfontein 9300, South Africa * Corresponding author, e-mail: albrecht.manegold@senckenberg.de A fragmentary skull of a small passerine from the mid-Holocene organic-rich deposits at Florisbad, South Africa, shows a pattern of distinctive characters that allows its identification as a Cercomela chat. It resembles most closely the Familiar Chat C. familiaris and Karoo Chat C. schlegelii, which are still part of the avifauna in this part of South Africa. Furthermore, the significance of several characters of the skull for hypotheses on the phylogeny of Muscicapoidea in general, and Saxicolinae in particular, is discussed. Florisbad, about 45 km north-north-west of Bloemfontein in the Free State, South Africa, is a fossil-rich spring mound deposit most famous for the great diversity of large mammals dating from the mid-Pleistocene, a skull fragment of an archaic human and Middle Stone Age artefacts (Brink 1987). Several thousand fossil specimens, most of them referable to mammals, were found during the early Florisbad excavations led by TF Dryer in the late 1920s and 1932, and by AC Hoffman in 1952 (Brink 1987, Manegold and Brink in press) and are now part of the so-called ‘Old Collection’ at the Florisbad Quaternary Research Station of the National Museum, Bloemfontein (Brink 1987). Bird remains are very scarce in the Old Collection; only 14 isolated bird bones were discovered, and half of them are identifiable as remains of Ostrich Struthio camelus, Greater Flamingo Phoenicopterus ruber roseus, Wattled Crane Bugeranus carunculatus, francolin cf. Scleroptila shelleyi and dabbling duck (Anatini, Anatidae) (Manegold and Brink in press). The remaining specimens are rather indistinct and nondescript splinters of bone. All these specimens stem from spring deposits and are of late mid-Pleistocene age (Manegold and Brink in press). Apart from these specimens, the Old Collection also contains a partial skull of a passerine that apparently is much younger in age. Its state of preservation and adhering matrix indicate that it was probably recovered from younger organic- rich deposits that formed during the mid-Holocene and that cover the spring deposits in the area of spring activity. Original information regarding the circumstances of its excavation and an original catalogue number is missing, but the skull’s packaging was such to reflect the time of Hoffman’s 1952 season of excavation. In many cases, specimens from the 1952 excavation were not individually numbered, but kept in packages labelled in Hoffman’s handwriting. Here, we present a description of the skull that shows characters of saxicoline chats of the genus Cercomela, which is still represented with several species in southern Africa. The described specimen FLO 7905 is part of the Florisbad vertebrate collection at the Florisbad Quaternary Research Station, National Museum, Bloemfontein. Comparisons were made with extant species of chats and Old World flycatchers (Muscicapidae) and representatives of other passerine taxa using the collections of the Iziko South African Museum, Cape Town, and the Forschungsinstitut Senckenberg, Frankfurt/Main, Germany (Appendix 1). Jon Fjeldså provided supplemental information on characters of Pogonocichla stellata, Sheppardia gunningi and S. sharpei based on specimens in the collections of the Zoological Museum of the University of Copenhagen, Denmark (ZMUC). Terminology of anatomical terms follows Baumel and Witmer (1993), though English translations are generally preferred over the Latin terms. Three sections of measure- ments were introduced for comparing the size of the incomplete fossil skull with that of the skulls of extant species; one section measures the maximal width of the skull on the level of the temporal region (section ‘α’; Figure 1a), another measures the width of the frontalia between the orbits (section ‘β’, corresponding to ‘SBO’ of von den Driesch 1976; Figure 1a) and the third measures the width on the level of the ectethmoids (section ‘γ’; Figure 1a). Results Systematic palaeontology Passeriformes (Linnaeus, 1758) Muscicapidae Fleming, 1822 Saxicolinae (Vigors, 1825) cf. Cercomela sp. Bonaparte, 1856 Material examined: FLO 7905, skull Locality and horizon The skull fragment FLO 7905 is of a dark colour and partially Materials and methods