4.4.2. Treatment of the corpse and embalming
The experimental approach which tested the trepanation method practiced on the mummy’s skull supports the hypothesis of a craniectomy by successive circular micro-drilling, obtained by the rotation of a tool applied perpendicularly to the bone surface. The flint tool, in the form of a driven point, used manually or with a bow, is compatible with the wear observed macroscopically on the edges of the trepanation. However, at the end of this experiment, an important point must be made. The flint tool wears out rapidly and must be replaced regularly (eight were used in this experiment). The need for more and more tools, whose morphology evolves over the course of the experiment, does not fit with the “standardization” effect implied by the regularity of the diameters of each drill phase carried out on the mummy. No doubt new tests, using different materials – always in keeping with what the cultural framework allows us to envisage – should be attempted in the future. On dry bone, obtaining a bone flap with a diameter of 20 cm2, made up of 20 confluent holes, required four hours of work. It is certainly probable that in the hands of experienced operators, the opening of the cranial cavity of the Chachapoya male would have required less time, but the methodical operation to which it testifies could not have been carried out quickly.
On the mummy, the edges of the trepanation are sharp and show no signs of healing. The constituent structures of the cranial vault, the external table, the diploe and the internal table are very clearly legible along the entire contour of the opening, and show no evidence of reworking. The edges are sharp and draw the contour of each drilling with precision. The trepanation of the mummy is thus comparable in every way to that carried out on dry bone, and thus implies a post-mortem operation. However, the absence of healing does not mean we can fully exclude the hypothesis of an in vivo trepanation, which would have been followed rapidly by the subject’s death. The location of the trepanation, which spares the main pericerebral vascular structures, suggests a strategic choice aimed at limiting the risk of bleeding, in contradiction with a post-mortem procedure. Nevertheless, it should be emphasized that the opening is also located astride the lambdoid suture, which suggests a high risk of complication. In addition, the skull’s skin, which is absent at the trepanation site, has the same serrated cut on some of its edges as the edges of the trepanation itself (Figure 4.3(b)). This indicates that the drilling was carried out directly from the outside of the scalp, which seems unlikely on a living subject.
The hypothesis of a post-mortem craniectomy remains the most parsimonious. The sophisticated arrangement of this large opening in the cranial cavity of the corpse of the young Chachapoya male can be related to the absence of the brain. The organ would have been removed at an early stage of the funereal process, at the time of the body’s burial. This hypothesis is consistent with the very first observations made by P. Broca for the mummies of Piedra Grande of Utcabamba, several of which bear the trace of unhealed cranial openings. He concluded, before of his colleagues of the Société d’anthropologie (French Society of Anthropology), that they had been subjected to a process of mummification whose objective was “[to] introduce aromatic substances into the skull to prevent putrefaction” (Broca quoted by Hamy (1897, p. 66)). With regard to the case of MNHN-HA-30187, this hypothesis is supported by P. Vidal-Senèze who affirmed that he had extracted “a sponge that took the place of the encephalon and must have been soaked with an antiseptic liquid” from the mummy’s skull (Vidal-Senèse in Hamy (1897, p. 66)). If the trepanation of this Chachapoya mummy was a stage of embalming, this must be distinguished from other cases of cranial perforations known in this same chrono-cultural context, whose traces of healing indicate an ante-mortem surgical gesture, and where the hypothesis of a cranioplasty practiced after trauma has been advanced (Kurin 2013).
Although the brain was removed from the corpse of the young Chachapoya male, the body was not completely eviscerated. At the abdominal level, the supra-diaphragmatic anatomical structures (lung and heart) are clearly visible. Under the diaphragm, the kidneys and liver are also present. On the other hand, the intestines and the stomach are not clearly identifiable. Have these tissues, which promote the decomposition processes, been extracted? Were the methods of evisceration of the mummy carried out in a “partial” manner, was this the norm or an alternative applied to particular deceased people? The existence of other noneviscerated Chachapoya mummies is attested, notably at Laguna Huayabamba (Muscutt 2003; Nystrom 2003). The possibly infectious nature of the corpse of MNHN-HA-30187 could explain a specific evisceration procedure that would have avoided contact with certain organs. An epidemiological study conducted on a larger scale, in conjunction with the meticulous restitution of mortuary gestures, would make it possible to test various embalming practices according to the health and social status of the deceased.
4.4.3. Chronology of mortuary gestures
Biological data on the insect species associated with the mummy allow us to suggest different hypotheses on the post-mortem “history” of this individual and to infer new data on Chachapoya funereal gestures. Calliphoridae diptera belong to the first waves of colonizers and lay their eggs on corpses within minutes of death (Huchet 2014; Huchet and Greenberg 2010). oviposition occurs most often in natural openings (eyes, nostrils, mouth, anus, etc.) but is also possible in open wounds. In this case, the very high concentration of puparia in the lower part of the body strongly suggests that the infestation started in this area of the body. The feet, thighs and perianal area show severe damage and degradation of soft tissue attributable to the action of the larvae. The larvae then colonized the interior of the abdomen as clearly indicated by medical imaging (Figure 4.10). It cannot be ruled out that a possible post-mortem treatment of rectal evisceration such as that described on the Chachapoya mummies of La Laguna de los Cóndores (Guillén 1998; Wild et al. 2007) could have favored the infestation by Calliphoridae flies. Another hypothesis is that the individual was colonized by these Diptera during his lifetime and died of myiasis14. Although the main cases of human myiasis in the Neotropics are due to various species of Calliphoridae (in particular the native species Cochliomyia hominivorax (Coquerel)), Dear (1985) indicates that certain species of the genus Compsomyiops can also cause myiasis in infected wounds. This assertion was recently confirmed by Guimaraes and Papavero (1999) who cite a case of myiasis due to Compsomyiops fulvicrura in Argentina.
If, however, colonization is considered more likely to have occurred postmortem, the fact that only one species of Diptera is present within the mummy indicates that the envelopment phase in the layers of tissue constituting the funereal bundle or fardo was carried out rapidly, probably within a few days of death. As Calliphoridae larvae leave the body to pupate at a distance, the presence of puparia inside the mummy indicates that this migration, inherent to the biology of these Diptera, was annihilated by the presence of the numerous layers of tissue. Depending on the species and environmental conditions, the length of the larval cycle in the feeding phase (i.e. before migration) of species of the genus Compsomyiops is between 4 and 10 days (Greenberg and Szyska 1984; Dale and Prudot 1986). The biological data reported by Dale and Prudot (1986) for C. arequipensis being between 4 and 5.9 days means that we can estimate that the body was packed in a time interval of less than 6 days.
Data from the study of insect remains present on the mummy indicates a relatively rapid funereal treatment and packaging of the body in fardo within less than 6 days. This conjecture is corroborated by the fact that the binding of the mummy in the fetal position was probably carried out only after complete disappearance of rigor mortis, that is, between 2 and 3 days after death. The hypothesis of myiasis having been the cause of death by toxaemia or sepsis is not to be totally ruled out. Finally, the phenology (periods of activity) of the species of the genus Compsomyiops would suggest that the death occurred during the hottest months of the year (i.e. between mid-August and early October for the Amazonas region).