Three cases of brachydactyly type E from two commingled tombs at the Late Intermediate period - Late Horizon site of Marcajirca, Ancash, Peru

Abstract

Objective: Here we present the first known examples of brachydactyly from an Andean archaeological context by describing the affected bones, presenting a differential diagnosis, and discussing the cultural implications of there being shortened metapodials in multiple tombs.

Materials: 3232 well-preserved tubular bones representing an MNI of 250 human adults.

Methods: Each bone was visually inspected. Measurements were taken with an osteometric board, sliding calipers, and a flexible tape measure.

Results: Of 1210 metapodials excavated from eight burial contexts, ten were atypically short.

Conclusions: The ten shortened elements represent an MNI of three individuals with brachydactyly from two tombs. The presence of at least two individuals with brachydactyly in one tomb adds support to a previous suggestion that tombs were used for familial interment. It is plausible that the third individual from a different tomb was related to the other two, and the different burial contexts may reflect postmarital practices.

Significance: These cases offer insight into tomb use and underscore the importance of identifying rare developmental anomalies in the archaeological record as their presence may indicate genetic relationships within or among archaeological cemeteries.

Limitations: With commingled contexts and incomplete recovery of skeletal remains, individualizing the brachydactylous elements was not possible. There is also a lack of comparative data from other Andean sites.

Suggestions for further research: Identify more Andean cases of brachydactyly to learn if the relatively frequent involvement of the first digit is more common among Andean skeletal samples than North American, or if it is unique to Marcajirca.

Keywords: Albright’s hereditary osteodystrophy; Brachymetacarpia; Brachymetatarsia; Developmental anomalies; Rare diseases; South America.