The dental developmental status of six East African juvenile fossil hominids

Abstract

Radiographs of five juvenile fossil hominids from Koobi Fora, Kenya are described and presented together with measurements and observations made on the original speciments. Data are also presented for a single specimen from Olduvai Gorge, Tanzania. Four of these specimens are attributed to Paranthropus boisei (KNM ER 812, 1477 1820 and OH 30), and are all of remarkably similar dental developmental status. Conventional age estimates for these specimens of Paranthropus based on the first permanent molar, indicate an age at death of around 2·2 to 3 years. Perikymata counts on permanent lower central incisors of these specimens also indicate an age at death between 2·5 and 3 years. Two specimens attributed to early Homo (KNM ER 820 and 1507), are dentally more mature than specimens of Paranthropus boisei described here being closer to 5 years of age. Differences between the spacing and distribution of perikymata on the surfaces of incisor teeth are now apparent between Homo, Australopithecus. Paranthropus boisei and Paranthropus robustus: these are described in this paper. Details of the dental developmental patterns of these hominids are also discussed in the light of recent publications that have presented data about hominid eruption sequences and fossil hominid growth periods.