Enigmatic Cranial Superstructures among Chamorro Ancestors from the Mariana Islands: Comparative Geographic Variation and a Proposal About Their Meaning

Publication Date

1-1-2021

Document Type

Article

Publication Title

Journal of Island and Coastal Archaeology

Volume

16

Issue

2-4

DOI

10.1080/15564894.2019.1638470

First Page

438

Last Page

481

Abstract

Sublime expression of three ectocranial occipital superstructures (OSSs)—occipital torus tubercles (TOTs), retromastoid processes (PRs), and posterior supramastoid tubercles (TSPs)—is virtually restricted to Oceania, with epicenters in the Mariana Islands, Tonga, Mocha Island, and perhaps other Oceanic locales such as the West Sepik Coast of New Guinea. Enigmatic in etiology, OSSs are anatomically related to entheses for the trapezius, superior oblique (suboccipital), and sternocleidomastoid muscles, respectively. Our study focuses on Latte Period (950–250 BP) Chamorro ancestors of the Mariana Islands, contextualized with other skeletal samples from Remote Oceania, Near Oceania, and the Asian and American Pacific Rims. Frequent co-variation and pair-wise patterning of multiple markedly expressed OSSs distinguishes ancestral Chamorros from all other populations, but markedly expressed individual OSSs exhibit a broad network of pan-Pacific morphological affinities. The presence of markedly developed PRs and TSPs in archaic Javanese hominins indicates deep Southeast Asian origins for these morphs, but a Northeast Asian origin for tuberculated TOTs is suggested by their earliest presence in Late Pleistocene Okinawans and Neolithic Taiwanese. The central goal of this paper is to present and evaluate evidence that OSSs are informative of both Pacific population history and the life histories of “bone-forming” Pacific Islander and Pacific Rim individuals.

Funding Number

ES05064

Funding Sponsor

National Institute of Environmental Health Sciences

Keywords

bioarchaeology, Micronesia, occipital superstructures, osteobiography, Pacific

Department

Anthropology

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