title: The timing of spheno-occipital fusion in hominoids.
abstract: The degree of spheno-occipital fusion has been used to assign a relative age to dentally mature hominoid cranial specimens. However, a recent study of captive individuals (Poe: Am J Phys Anthropol 144 (2011) 162–165) concluded that fusion of the spheno-occipital suture in great ape taxa is of little utility for aging dentally mature individuals. In this contribution, I use dentally mature samples of extant hominoid taxa (Homo sapiens, Pan troglodytes schweinfurthii, Gorilla gorilla gorilla, Pongo pygmaeus pygmaeus and Hylobates lar) to investigate a) the temporal relationship between spheno-occipital fusion and dental maturity, b) whether there is an association between the degree of spheno-occipital fusion and relative age, c) whether there are differences in relative timing of spheno-occipital fusion between taxa, and d) whether there are sex differences in the relative timing of spheno-occipital fusion. Results suggest that a) a substantial proportion of dentally mature wild-shot chimpanzee, gorilla and orang-utans have unfused or partially fused spheno-occipital synchondoses, b) there is an association between the degree of spheno-occipital fusion and age, c) there are interspecific differences in the timing of spheno-occipital fusion, and d) there are significant sex differences in spheno-occipital fusion in chimpanzees, orang-utans and gibbons. Thus, contrary to previous work, degree of spheno-occipital fusion is a potentially useful indicator of relative maturity, especially in great ape taxa.
authors.affiliation: Center for the Advanced Study of Hominid Paleobiology, Department of Anthropology, George Washington University, WA, DC, 20052; Department of Anthropology, University College London, London, WC1H 0BW, UK.
authors.forename: Katharine L
authors.initials: KL
authors.lastname: Balolia
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D000818:Animals; D000885:Anthropology, Physical; D003393:Cranial Sutures; D005260:Female; D015186:Hominidae; D006801:Humans; D008297:Male; D008875:Middle Aged; D009777:Occipital Bone / Q000033:anatomy & histology* / Q000254:growth & development*; D012727:Sex Characteristics; D013100:Sphenoid Bone / Q000033:anatomy & histology* / Q000254:growth & development*; D055815:Young Adult
keywords: aging; basilar suture; maturity; sexual dimorphism; synchondrosis