title: A new partial temporal bone of a juvenile hominin from the site of Kromdraai B (South Africa).
abstract: The site of Kromdraai B (KB) (Gauteng, South Africa) has yielded a minimum number of nine hominins including the type specimen of Paranthropus robustus (TM 1517), the only partial skeleton of this species known to date. Four of these individuals are juveniles, one is a subadult and four are young adults. They all occur with a macrofaunal assemblage spread across the succession of at least two time periods that occurred in South Africa approximately two million years ago. Here we report on an additional, newly discovered petrous temporal bone of a juvenile hominin, KB 6067. Following the description of KB 6067, we assess its affinities with Australopithecus africanus, P. robustus and early Homo. We discuss its developmental age and consider its association with other juvenile hominin specimens found at Kromdraai B. KB 6067 probably did not reach five years of age and in bony labyrinth morphology it is close to P. robustus, but also to StW 53, a specimen with uncertain affinities. However, its cochlear and oval window size are closer to some hominin specimens from Sterkfontein Member 4 and if KB 6067 is indeed P. robustus this may represent a condition that is evolutionarily less derived than that shown by TM 1517 and other conspecifics sampled so far. The ongoing fieldwork at KB, as well as the petrography and geochemistry of its deposits, will help to determine when the various KB breccias accumulated, and how time may be an important factor underlying the variation seen among KB 6067 and the rest of the fossil hominin sample from this site.
authors.affiliation: Computer-Assisted Palaeoanthropology Team, UMR 5288 CNRS-Université de Toulouse (Paul Sabatier), 37 Allées Jules Guesde, 31000 Toulouse, France; Ditsong National Museum of Natural History, 432 Paul Kruger Street, Pretoria 001, South Africa. Electronic address: jose.braga@univ-tlse3.fr.
authors.forename: José
authors.initials: J
authors.lastname: Braga
authors.forename: John Francis
authors.initials: JF
authors.lastname: Thackeray
authors.forename: Jean
authors.initials: J
authors.lastname: Dumoncel
authors.forename: Didier
authors.initials: D
authors.lastname: Descouens
authors.forename: Laurent
authors.initials: L
authors.lastname: Bruxelles
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Loubes
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Kahn
authors.forename: Marco
authors.initials: M
authors.lastname: Stampanoni
authors.forename: Lunga
authors.initials: L
authors.lastname: Bam
authors.forename: Jakobus
authors.initials: J
authors.lastname: Hoffman
authors.forename: Frikkie
authors.initials: F
authors.lastname: de Beer
authors.forename: Fred
authors.initials: F
authors.lastname: Spoor
mesh_terms: D000818:Animals; D005075:Biological Evolution; D015186:Hominidae / Q000033:anatomy & histology* / Q000145:classification; D010579:Petrous Bone / Q000033:anatomy & histology*; D010802:Phylogeny; D013019:South Africa
keywords: Australopithecus africanus; Bony labyrinth; Cochlea; Early Homo; Paranthropus robustus; Pleistocene