Connecticut Indian Skull - May Show Trephination

(Reprinted from SCIENCE 13 November 1970, Volume 170, pp. 732-734 1,903 words)

Aboriginal Trephination: Case from Southern New England?

Bernard W. Powell

Abstract. The skull of a young adult male Amerind from a grave at a coastal site in southern Connecticut bears a largely cicatrized elliptical anomaly near bregma. Some evidence suggests deliberate antemortem trephination of the scraping type. The specimen is of interest since perhaps fewer than twenty human skulls have been advanced as putative cases of trephining by North American aborigines.

A HUMAN BURIAL at Spruce Swamp, a site of former Indian occupancy at Norwalk, Fairfield County, Connecticut (1), was vandalized by road workers who discovered it after my formal field work was completed. The individual was a young adult, probably male, whose age at death was estimated to be between 20 and 25 years on the basis of absence of tooth wear and suture closure. He had apparently been buried semiflexed, on his side, head to east, and about 0.5 m deep in loam above a glacial terrace on Long Island Sound. Quartz debitage, scattered marine shell fragments, and, notably, a clay sherd in the grave fill relate the burial tenuously to the Woodland Period. Apparently there were no deliberate grave offerings or mortuary furniture. I designated the find Spruce Swamp Burial 1 (B. 1).

By sifting the disturbed soil in the vicinity of the grave with a 7-mm screen, I recovered about 50 percent of the postcranial skeleton and 90 percent of the cranium. The cranium was reconstructcd and stabilized by immersion for several days in Alvar 7/70 solution. At that time it became apparent that a peculiar condition obtained near bregma.

Specifically, there is an only slightly elliptical cavity, which is 35 mm long by 33 mm wide and is a maximum of 7 mm deep, with the long axis parallel to the long axis of the skull and overlying the superior sagittal sinus. A thin bony floor, varying from 1 to 3 mm in thickness, covers more than 90 percent of the bottom of the cavity. A ridge of bony growth, which opens posteriorly, partially surrounds the cavity on the outer table in a shape rather like a horseshoe (see Fig. 1A).

The remainder of the cranium is normal. Wormian bones are present in the lambdoid suture. Deformation by earth pressure is not marked. Sand grains and drusy mineral crusts on the inner table probably record transient groundwater penetrations.

The general appearance suggests trephination. A search of the literature fails to disclose references to trephining for this region. The practice is worldwide at many time levels but is most marked in the New World, especially among the highland Incas of Peru (2). Stewart (3) lists fewer than 20 instances of putative cases of trephining in North America and admits to a dissatisfaction with evidence and arguments advanced in the literature. He cites a specimen from Maryland as the best example yet found in North America, but he feels it is suspect since it was an isolate among unmodified skulls.

However, Stewart concedes that "according to modern pathological knowledge, no other diagnosis fits as well" (3, p. 476). Other locales cited by him include Alaska, Arkansas, British Columbia (five specimens), Georgia, Kodiak Island, Mexico, Michigan, and New Mexico. Trephining may be postmortem or antemortem; many writers fail to make this distinction.

Fig. 1. (A) Superior aspect of B. 1 cranium from the Spruce Swamp site. A large portion of the left parietal is missing. (B) Left lateral aspect of B.1. Note angular bony ridge apparent anteriorly to anomaly in profile.

Postmortem trephining is thought to be largely thaumaturgic in origin and is responsible for the rondelles frequently cited for the European Paleolithic. Such disks, both in the Old and New Worlds, were often further modified by boring and scraping, presumably to serve as amulets, personal charms, and fetishes. Antemortem trephination is thought to he largely therapeutic in origin, and the presence or absence of bony replacement records whether individuals survived the operation. Different appearances of "green" and dry bone when cut or broken help distinguish valid postmortem trepanning from antemortem trepanning followed by immediate death. In a classic study of trephining among the Peruvian Yauyos, Tello (4) reports 250 cicatrices among a total of 400 skulls with antemortem trephining. The presence of cicatrization in the B. 1 cranium indicates that the anomaly was not an immediate cause of death.

Natural holes in human skulls may be caused by diseases, notably osteoperiostitis, rarefying osteitis from lesions of the periosteum, and syphilis; by anomalies such as congenital aperture with hernia of the brain and meninges; and by genetic conditions such as parietal fenestrae ("Catlin marks") (4, 5). Placement (bilaterally symmetrical holes in parietals for Catlin marks) and presence of ancillary conditions (stellar gumma cicatrices in syphilis; everted edges in hernia; and other diseased conditions) help eliminate cases otherwise referable to trephining. There are no such conditions for the B. 1 cranium. Wells (6) illustrates "horns" from sebaceous cysts, which he says leave marks on the skull “indistinguishable" from healed trepans. Presumably this condition is rare.

Fig. 2. (A) Superior aspect of cranium 18, a triple-trephined skull of a middle-aged Inca from Cuzco. (B) Left lateral aspect of cranium 18. Note angular bony ridge apparent posteriorly in profile around uppermost aperture. [From plates XXXVII and XXXVIII, Muniz and McGee (9)]

Scraping, boring, and sawing, as well as a lesser known rubbing technique, were all used in primitive trephining. Scraping often yielded ellipsoid cavities with their long axes in the direction of the scraping. Boring left buttons of bone and round holes in skulls; it is the method of modem neurosurgeons. Sawing, usually accompanied by elevating individual bone polygons freed by the kerfs, was a common method among the Inca. Of these techniques, the B. 1 specimen most suggests the scraping technique, which may have stopped short of complete removal of all bone (Fr. raclage trephine).

Fractures are probably the most common motive for trephining; primitive warfare and daily hazards might be expected to result in a fair number of such wounds. One authority, Fletcher (7), notes that the well-defined, beveled edges of trephined apertures contrast to the "blows of stone hammers or axes [which] resulted generally in necrosis, or death of the bone, and often disruption or bulging of the inner table of the skull for some distance from the seat of the

injury." He cites examples of the latter condition from a prehistoric cemetery near Madisonville, Ohio. Radiating fractures, in contrast to depressed fractures, show radial cracks around the point or points of impact. If a fracture preceded the B.1 anomaly, no evidence is discernible on the inner table, and the presumptive trephination and healing have obliterated any evidence on the outer table and diploe.

Fletcher (7) says further of trephined apertures that they are nearly always elliptical; they fall within a range of 35 to 50 mm in length and 6 to 10 mm in width; and they show oblique edges at the expense of the outer table. The B. 1 cranium fulfills these criteria, save for that of width. This size range, however, seems restrictive to me, judging from relative appearance of illustrated Inca remains.

In a study of perforated crania from southern Michigan, Hinsdale and Greenman (8) indicate a point near bregma as a preferred locus for perforations (again like B.1), but the Michigan specimens were postmortem trephinations. They postulated cultural connections south and east of Michigan.

The B.1 cranium shows striking parallels to a known triple-trephined skull of a middle-aged Inca (Fig. 2) designated as cranium 18 by Muniz and McGee (9). These parallels are a trephination near bregma; bony ridges in profile around the trephination (see Fig. 1B and Fig. 3); an inner table with visible suture remnant; and a horseshoe shape, opening posteriorly. This last condition prompted the authors to posit that the operation was done by a righthanded individual with the patient’s head between his knees and the patient supine before him, with both patient and operator facing the same direction.

It would seem that the B. 1 cranium might be advanced as a case of antemortem trephining on the following grounds: absence of bone erosion or rarefaction as in disease; no evidence for either a depressed or a radiating fracture; well-defined, beveled exterior edges, oblique at the expense of the outer table; ellipsoid shape; length within a cited range for primitive trephination; evidence of bony regrowth; and general similarity in appearance and in orientation to a verified Inca trepan.

T. Stewart, who has examined many trepans on skulls in the U.S. National Museum collections, suggested that the B. 1 cranial aperture might be from a cyst or tumor. He conceded, however, that be had never seen anything quite like this specimen. Of five pathologists who examined the skull, four were flatly of the opinion that it was a trephination and not meningioma or other disease; the fifth, M. Helpern, a specialist in forensic medicine, suggested that a downward invasion of a basal cell tumor of the scalp could cause the condition, but he declined ultimately to say definitely what the lesion represented. H. Jaffee may have effected a marriage of the opposed viewpoints of disease and trephining; he raised the possibility that the anomaly might result from a long-standing lesion which prompted attempts to scrape or treat it.

What a trephined skull might mean at the Spruce Swamp site is unclear. Both generalized regional Archaic and Woodland levels have been postulated here (1), with only tenuous suggestion of exotic elements. These include an artifact of plasma (a stone material identified as originating in Georgia or Alabama) and an enigmatic incised paintstone (10), which may record Southern cult motifs.

The presumptive trephination may be an isolate, or it may relate to cultural practices or influences inadequately recorded in the literature. Certainly the unskilled and fragmentary recovery of most Indian burials in this region plus unrestricted "pothunting," may have destroyed much evidence.

Bernard W. Powell
Stonebridge Road,
Wilton, Connecticut, 06897

References and Notes

1. B. Powell, Amer. Antiquity 30, 460 (1965).
2. J. Daland. Ann. Med. Hist. 7, 550 (1935).
3. T. Stewart, in Smithsonian Institution Annual Report of 1957 (Government Printing Office, Washington, D.C., 1958), pp. 469-491.
4. J. Tello, Prehistoric Trephining among the Yauyos of Peru (Harrison, London, 191-) pp. 75-83.
5. W. Goldsmith, Amer. Antiquity 10, 348 (1945).
6. C. Wells, Bones, Bodies and Disease (Praeger, New York, 1964) plate 82.
7. R.. Fletcher, in Contributions to North American Ethnology (Government Printing Office, Washington, D.C. 1882) pp. 5-30
8. W. Hinsdale and E. Greenman, Perforated Indian Crania in Michigan (Univ. of Michigan. Press, Ann Arbor, 1936) pp. 1-15
9. M. Muniz and W. McGee, in Sixteenth Annual Report of the Bueau of American Ethnology (Government Printing Office, Washington, D.C., 1897), pp 11-72.
10. B. Powell, Amer. Antiquity 30, 98 (1964).
11. I thank T. Stewart, United States National Museum; M. Helpern, Chief Medical Examiner, and his staff, New York City; and H. Jaffee, Hospital for Joint Diseases, New York City, for their examinations of, and comments on, the cranium from B.1. I also thank R. Colmers, Medical Examiner of Stamford, Connecticut, and J. Gifford of the Department of Anthropology, Temple University, for encouragement and other assistance in carrying out this project.

17 August 1970