M Christopher Dean1, Helen M Liversidge2. 1. a Department of Cell and Developmental Biology , University College London , London , UK and. 2. b Queen Mary University of London, Institute of Dentistry , London , UK.
Abstract
BACKGROUND: Previous studies have used molar tooth eruption as a comparative marker of maturation in early fossil hominins. However, tooth eruption and tooth formation are independent maturational processes. AIM: To determine whether estimates of age for entering a stage of dental development in three early hominin fossils fell within the distribution of a modern human sample. METHODS: This study used a comparative model of dental development to identify the stages of dental development most likely to provide information about length of the growth period in early fossil hominins. Age estimates for stages of dental development in fossils were superimposed onto a normal distribution of the same radiographically defined stages derived from a sample of 6540 children of diverse geographical origin. RESULTS: Both within the dentition of S7-37, from Sangiran, Java, but also for stages of two other specimens (KNM-WT 15000 from Kenya and StW 151 from South Africa), all age estimates for later stages of tooth formation fell within the modern sample range. CONCLUSIONS: A pattern appears to exist in early Homo where, both within and between developing dentitions, age estimates for stages of P4, M2 and M3 tooth formation fell consistently among the more advanced individuals of the modern human sample.
BACKGROUND: Previous studies have used molar tooth eruption as a comparative marker of maturation in early fossil hominins. However, tooth eruption and tooth formation are independent maturational processes. AIM: To determine whether estimates of age for entering a stage of dental development in three early hominin fossils fell within the distribution of a modern human sample. METHODS: This study used a comparative model of dental development to identify the stages of dental development most likely to provide information about length of the growth period in early fossil hominins. Age estimates for stages of dental development in fossils were superimposed onto a normal distribution of the same radiographically defined stages derived from a sample of 6540 children of diverse geographical origin. RESULTS: Both within the dentition of S7-37, from Sangiran, Java, but also for stages of two other specimens (KNM-WT 15000 from Kenya and StW 151 from South Africa), all age estimates for later stages of tooth formation fell within the modern sample range. CONCLUSIONS: A pattern appears to exist in early Homo where, both within and between developing dentitions, age estimates for stages of P4, M2 and M3 tooth formation fell consistently among the more advanced individuals of the modern human sample.
Entities:
Keywords:
Australopiths; age estimation; dental development; dental histology; early Homo; hominin; human evolution; radiography
Authors: Song Xing; Paul Tafforeau; Mackie O'Hara; Mario Modesto-Mata; Laura Martín-Francés; María Martinón-Torres; Limin Zhang; Lynne A Schepartz; José María Bermúdez de Castro; Debbie Guatelli-Steinberg Journal: Sci Adv Date: 2019-01-16 Impact factor: 14.136