Is that shrunken head really human? Combining imaging methods yields clues - Ars Technica

Enlarge / 3D rendered representation of the micro-CT scan of a tsantsa, oregon shrunken head.

Andrew Nelson, CC-BY 4.0

There's seldom clip to constitute astir each chill science-y communicative that comes our way. So this year, we're erstwhile again moving a peculiar Twelve Days of Christmas bid of posts, highlighting 1 subject communicative that fell done the cracks successful 2020, each time from December 25 done January 5. Today: Sophisticated imaging methods tin beryllium utilized to authenticate whether the shrunken heads (tsantsas) successful depository collections are genuine.

In Tim Burton's 1993 animated diagnostic The Nightmare Before Christmas, there's country wherever a small lad receives a shrunken head arsenic a Christmas acquisition from Jack Skellington. It does not spell implicit well, with either the lad oregon his parents. But determination was a clip successful the aboriginal 20th period erstwhile these macabre objects were successful specified large request by Western collectors that it triggered a lucrative marketplace for counterfeits. Many museums astir the satellite number shrunken heads (known arsenic tsantsas by the Shuar people) among their collections, but however tin curators find if those items are authentic? Certain blase imaging methods tin help, according to an August paper published successful the diary PLoS One.

The signifier of headhunting and making shrunken heads has mostly been documented successful northwestern parts of the Amazon rainforest, arsenic good arsenic among definite tribes successful Ecuador and Peru, similar the Shuar. Accounts struggle connected the circumstantial details of the manufacturing process. But the tsantsas were typically created by removing the tegument and soma from the skull's cranium via an incision connected the backmost of the ear, and past discarding the skull. The nostrils were packed with reddish seeds and the lips sewn shut. Next, the tegument was boiled successful h2o saturated with tannin-rich herbs for 15 minutes to 2 hours, truthful that the abdominous and grease would interval to the top. This besides caused the tegument to declaration and thicken. Then the caput was dried with blistery rocks and molded backmost into thing resembling quality features and the eyes were sewn shut. As a last interaction the tegument was rubbed with charcoal ash—apparently to support the avenging psyche from escaping—and sometimes beads, feathers, oregon different adornments were added for decoration.

Traditionally, the completed tsantas were displayed connected poles wrong houses—not worn, per the authors of the August paper, contempt what 1 mightiness work successful the existing anthropological literature. Shrunken heads were a fashionable collectible among Victorian-era priests, Europeans, and American explorers anxious to bring exotic things backmost for their backstage collections. Eventually a commercialized marketplace developed arsenic the signifier became much broadly known aft 1860. But these commercialized tsantsas were often made from carnal skins (usually pigs, monkeys, oregon sloths), though immoderate were made from quality heads collected from corpses successful morgues. The manufacturers nevertheless claimed their wares were genuine.

Lauren September Poeta of Western University successful London, Ontario, and her coauthors estimation that arsenic overmuch arsenic 80 percent of the tsantsas presently kept successful collections worldwide are of commercialized origin, and determination are precise fewer reliable methods susceptible of determining their existent origin. Curators person usually relied connected ocular inspections oregon CT scanning for authentication. But Poeta et al. enactment that 4 cardinal features are poorly resolved utilizing modular CT scanning: the stitching, oculus anatomy, receptor anatomy, and scalp anatomy. So they decided to spot if they could amended the solution of those features by combining CT scanning with high-resolution micro-CT scanning—an attack known arsenic correlative tomography.

The squad utilized a tsantsa from the postulation of the Chatham-Kent Museum successful Chatham, Ontario, acquired by the depository successful the 1940s from a section household who bought it portion exploring the Amazonian basin. The lone enactment of root was that it came from "Peruvian Indians," and determination was nary definitive impervious that the Chatham tsantsa was the genuine article. The researchers did a objective CT scan of the full entity and 2 micro-CT scans—one of the full head, the different a high-resolution scan of portion of the scalp—using a instrumentality astatine the Museum of Ontario Archaeology.

Poeta and her colleagues confirmed that the Chatham tsantsa is made of genuine quality remains, though they could not find whether it was made ceremonially oregon commercially. The unsmooth chopped astatine the backmost of the skull and the usage of double-hiding are accordant with the former, but modern thread was utilized to stitch the incision, eyes, and lips, which suggests commercialized production. "In fact, it whitethorn beryllium that the part betwixt ceremonial and commercialized manufacture is much hard to specify than mostly believed, arsenic the signifier of creating tsantsas apt exists connected a spectrum alternatively than an either/or dichotomy," the authors wrote.

More mightiness beryllium learned by subjecting tsantsas of known provenance to correlative tomography imaging. The authors concluded that portion accepted CT scanning remains utile for reconstructing a basal visualization of these fascinating artifacts—enabling researchers to intimately analyse them without risking harm from repeated handling—micro-CT scanning tin find whether a fixed tsantsas is made of quality materials, and supply higher solution details for circumstantial features.

DOI: PLoS ONE, 2022. 10.1371/journal.pone.0270305 (About DOIs).