Department of Retracted - jns...Aztec’s capital, whose vestiges still remain next to Mex-ico City’s Metropolitan Cathedral (Metropolitan Cathe-dral of the Assumption of Mary of

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Before the discovery of the Americas by Chris-topher Columbus in 1492, the central region of the continent, known as Mesoamerica (extend-

ing from Central Mexico to Nicaragua), was inhabited by prosperous ancient civilizations that flourished before the Spanish colonization that began in the 16th century.14 Pre-Columbian Mesoamerican societies (Olmecs, Ma-yans, Totonacs, Aztecs, and Mixtecs) shared not only a geographical area but also several cultural traits.14 As early as 7000 to 6000 Bc, they domesticated the wild teo-sinte and gradually transformed it by selection of seeds into the ancestor of modern maize. It became the major crop of Mesoamerican societies by the time of Spaniard exploration.2,13,18 Improvement of agricultural techniques and domestication of maize and other vegetables (beans, squash, and chilies), as well as the raising of turkeys and the Mexican hairless dog (Xoloitzcuintli), caused a tran-sition from paleo-Indian hunter-gatherers (foragers) to established agricultural villages.16

During the centuries following the establishment of

the first agricultural settlements, several common social and cultural features evolved among Mesoamerican soci-eties, such as complex calendar and numeral systems, rich and colorful mythological traditions, advanced astronom-ical knowledge, and a distinct architectural style, whose vestiges still remain. Human sacrifice became a common cultural trait during the advanced phases of Mesoameri-can civilizations.5,12 This phenomenon, influenced by complex religious beliefs, included several practices such as decapitation,3,9,12 cranial deformation,20 and the use of human cranial bones for skull mask manufacturing.15 Ar-chaeological evidence suggests that all of these practices required specialized knowledge of cranial, skull base, and upper cervical anatomy.10 In the context of a world of perpetual war among tribes and hand-to-hand combat,3 considerable surgical applications might have emerged from this anatomical knowledge, such as the use of gold and silver to perform cranioplasties, refined surgical tech-niques to treat combat wounds, and the development of head protection devices.11

Knowledge of skull base anatomy and surgical implications of human sacrifice among pre-Columbian Mesoamerican cultures

Raul lopez-SeRna, M.D.,1 Juan luiS GoMez-aMaDoR, M.D.,1 Juan BaRGeS-Coll, M.D.,1 niCaSio aRRiaDa-MenDiCoa, M.D.,1 SaMuel RoMeRo-VaRGaS, M.D., M.SC.,2 MiGuel RaMoS-peek, M.D.,1 MiGuel anGel CeliS-lopez, M.D.,1 RoGelio ReVuelta-GutieRRez, M.D.,1 anD leSly poRtoCaRReRo-oRtiz, M.D., M.SC.3

1Department of Neurosurgery, Instituto Nacional de Neurologia y Neurocirugia “Manuel Velasco Suárez;” 2Department of Spine Surgery, Instituto Nacional de Rehabilitación; and 3Department of Neuroendocrinology, Instituto Nacional de Neurologia y Neurocirugia “Manuel Velasco Suárez,” Mexico City, Mexico

Human sacrifice became a common cultural trait during the advanced phases of Mesoamerican civilizations. This phenomenon, influenced by complex religious beliefs, included several practices such as decapitation, cranial deformation, and the use of human cranial bones for skull mask manufacturing. Archaeological evidence suggests that all of these practices required specialized knowledge of skull base and upper cervical anatomy. The authors con-ducted a systematic search for information on skull base anatomical and surgical knowledge among Mesoamerican civilizations. A detailed exposition of these results is presented, along with some interesting information extracted from historical documents and pictorial codices to provide a better understanding of skull base surgical practices among these cultures. Paleoforensic evidence from the Great Temple of Tenochtitlan indicates that Aztec priests used a specialized decapitation technique, based on a deep anatomical knowledge. Trophy skulls were submitted through a stepwise technique for skull mask fabrication, based on skull base anatomical landmarks. Understanding pre-Columbian Mesoamerican religions can only be realized by considering them in their own time and according to their own perspective. Several contributions to medical practice might have arisen from anatomical knowledge emerging from human sacrifice and decapitation techniques.(http://thejns.org/doi/abs/10.3171/2012.6.FOCUS12120)

key WoRDS • skull base • forensic anthropology • funeral rites • shamanism

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See the corresponding retraction, DOI: 10.3171/2018.5.FOCUS12120r, for full details.

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Systematic SearchWe conducted a systematic search for information

on skull base anatomical and surgical knowledge among Mesomerican civilizations. For this purpose, we exam-ined the collections of the Mexican National Institute of Anthropology and History and the National Autonomous University of Mexico, as well as previous reports of os-teological and pictorial collections obtained from excava-tions at some major archeological sites.

A detailed exposition of these results is presented, along with some interesting information extracted from historical documents and pictorial codices, to provide the reader with some valuable information concerning the existence of skull base surgical practices among these ancient cultures.

The Aztecs and the Great City of TenochtitlanThe Aztecs, also known as Mexicas, inhabited the

land we now call the Valley of Mexico, where Mexico City is situated. The ancient city of Tenochtitlan—the Aztec’s capital, whose vestiges still remain next to Mex-ico City’s Metropolitan Cathedral (Metropolitan Cathe-dral of the Assumption of Mary of Mexico City)—was founded in 1323, on a little swampy islet in Lake Texcoco. According to legend, this unexpected place was selected by Aztec religious leaders because it is where they saw a golden eagle perched on a paddle cactus, eating a snake.6 Graphic representation of this legend is depicted on the Mexican coat of arms, which can be seen on the white stripe of the Mexican flag.

Over the decades, the Aztec civilization formed a powerful warrior empire that expanded its political and economical hegemony beyond the Valley of Mexico. At the maximal extent of the Aztec Empire, Tenochtitlan ex-tended its power as far as the shores of the Gulf of Mexico and Pacific Ocean.18

Inspired by their religious beliefs, the Aztecs launched periodical ritual battles against their enemies, which pro-vided them with victims for sacrifice. According to the Duran Codex, these battles, known as “flower wars,” were instigated by the Aztec emperor Tlacaelel after a great famine, in an attempt to please the gods and obey their wishes.5,11

The Great Temple (Huey Teocalli) was the main reli-gious building of Tenochtitlan. It was a twin temple dedi-cated to 2 gods: Tlaloc, god of rain, and Huitzilopochtli, god of war. According to Aztec tradition, the temple was built on the exact site of the city’s stone foundation.9 Dur-ing the Spanish conquest of Tenochtitlan, the Great Tem-ple, like most of the ancient city, was almost destroyed, and its building materials were reused to erect the new colonial city over the remains of the ancient Aztec capi-tal. The location of the Great Temple was forgotten until the 20th century, when workers from the National Elec-tric Company discovered it by accident during excavation work next to the Mexico City Metropolitan Cathedral.

The archeological site of the Great Temple of Tenoch-titlan covers an area of almost 4000 m2. Some of its most important buildings are the Great Temple itself, the ball court, the Calmecac (school for the wealthy class), and the

temples dedicated to the gods Quetzalcoatl and Tezcatli-poca.6 The Great Temple of Tenochtitlan represented the axis mundi of Aztec civilization, and most of the religious practices were performed there (including decapitation); thus it is not surprising that most of the Aztec osteologi-cal specimens come from this site, where they gradually accumulated over a period between 1440 and 1502 ad.4

Knowledge of Skull Base Anatomy and the Practice of Human Sacrifice Among AztecsFray Bernardino de Sahagun, known as one of the

most important chroniclers of the 16th century, exten-sively described the Aztec way of life in his 12-volume Florentine Codex. From this written evidence, it is known that parents decided the future profession of their ba-bies immediately after birth. Future priests had to go to the Calmecac, where they received a rigorous education based on a specific program. As suggested by chroniclers, Aztec priests may have begun their training as early as 5 years old, and they had to learn both theory and practice, such as the technique for human sacrifice and decapita-tion. The Aztec priests were experts on anatomy of in-ternal and external anatomical structures and used spe-cific names for brain (cuayolotl) and head (tzontecomatl). Furthermore, they distinguished the skull base and upper cervical spine (cuitla) as an independent structure from the rest of the cranium (cuech) and spine (xo).7

Paleoforensic evidence from more than 1000 bone specimens found in 19 offerings from the Great Temple indicates that Aztec priests used a specialized and sys-tematic decapitation technique, possibly based on a deep knowledge of skull base anatomy.4 Some osseous marks show a recurrent pattern among different specimens and correspond to cuts inflicted on the occipitocervical junc-tion with fine tools, probably obsidian or quartz knives (tecpatl; Fig. 1 left).7 These V-shaped indentations, located over the upper cervical vertebrae and occipital condyles,9 might have followed a blunt dissection of the upper neck, with the intention of damaging the upper spinal cord and lower medulla oblongata. All cases of decapitation were performed with the individual lying on his or her back; after the victims were sacrificed, the priests decapitated them between the fifth and sixth cervical vertebrae (Fig. 1 right).10 Trophy skulls had 3 possible uses: as an offering inside the temple, with the flesh intact; for public display on a skull rack (tzompantli); and for fabrication of orna-mental masks (Fig. 2).

Anatomical Landmarks for Skull Mask Fabrication: Abrasion Technique

Life and death were not separate states for Meso-american civilizations; the vital force was eternal, and life on Earth constituted only a momentary lapse of eternity. Skull masks represented a link between life and death, which explains why their fabrication was not an isolated practice, but a common phenomenon among Mesoameri-can civilizations.15

Evidence from osteological collections from several

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Mesoamerican cultures (Aztec, Mixtec, Totonac, and Ma-yan) suggests that the fabrication process of skull masks followed a stepwise standardized approach (Fig. 3).4 First, the scalp was removed and temporal muscles were elevated downward, to the level of the zygomatic arches, as suggest-ed by marks of flesh scraping over temporal squamae. Sec-ondly, the parietal bones, occipital bone, and the posterior part of the temporal bones were excised by a combination of percussion and cleavage by abrasion. Preservation of the pterion at this stage is a common finding among masks, perhaps explained by the hardness of the sphenoid wing. The third part of the process involved abrasion of the lower and middle clivus; at this stage, preservation of the poste-rior clinoid process and sella turcica is a common finding among specimens, which suggests some aesthetic or sym-bolic value of the sellar region. Finally, some materials—mainly conch and pyrite—were encrusted within the orbits, and obsidian, quartz, or flint knives were placed in the oral and nasal cavities.4 Once finished, skull masks occupied the same level in the offerings that the effigies of gods did; this fact can give us insight into their extraordinary icono-graphic value.15

The Influence of Anatomical Knowledge on Therapeutics

The practice of decapitation might have influenced the way Mesoamericans conceived of and treated neuro-

logical diseases.7 Aztecs had their own Terminologia An-atomica and used specific terms for various neurological disorders; they knew that severe cranial trauma (cuech-poztequi) could cause hallucinations (chichihualayatl) and deep stupor (yohualtetzahuitl); in fact, there is arche-ological evidence of cranial trepanation in an attempt to treat these lesions.19 However, Aztecs knew perfectly well that severe trauma or penetrating wounds (tlaxilli) on the skull base and upper cervical spine (cuitlapoztequi) were severely disabling and mostly lethal. Aztec physicians (ticitl) knew that surviving these lesions would make someone “macocoltzin,” which literally means “man with crippled hands,” and thus lesions of the cuitlapoztequi were not usually treated because of their poor progno-ses. Ancient Mesoamerican physicians were interested in neurosurgery, and several sculpted models and figurines coming from the Totonac civilization represent examples of skull base disorders, such as orbitary tumors and post-traumatic facial paralysis (Fig. 4).

Other examples of primitive skull base surgery can be found in Mayan remains. Health care and medicine among the ancient Mayans was delivered only by a very select caste of priests and physicians, who received exten-sive education and specialization. Archeological sources show several ancient Mayan medical practices, such as suturing of wounds with human hair, fracture reductions, and dental prostheses made of turquoise and jade. An-cient Mayan dentistry and craniofacial surgery must have been able to treat complex pathologies of the skull base, such as mandibular and maxillary tumors.1

Considering the level of expertise and specializa-tion among Mayan physicians, along with other practices such as cranial deformation20 and human sacrifice,5 it is not baseless to speculate that this civilization might have closed the gap between anatomy and pathology in terms of skull base knowledge, given that there is archeological evidence of successful surgical drainage of maxillary and middle fossa abscesses through trepanation.19

DiscussionThe reasons that pushed ancient Mesoamerican civi-

Fig. 1. Photographs of bones found at the Aztec Great Temple at Tenochtitlan. Left: Lateral aspect of the atlas. A V-shaped mark (ar-row) was made on its lateral mass. Right: C-5 articular facet with signs of trauma next to its articular surface (arrow). C-5 and C-6 were the preferred levels for decapitation among Aztec priests. Reproduced with permission from the National Institute of Anthropology and History (INAH)/Museo del Templo Mayor Collection.

Fig. 2. Images showing 3 uses of trophy skulls after decapitation. A: Plate 4 of the Borgia Codex depicting the burial of a tro-phy skull inside a temple. B: Plate of the Ramirez Codex showing a pallisade with human crania (Tzompantli). C: Ornamental skull mask encrusted with stones. Reproduced with permission from the National Institute of Anthropology and History (INAH).

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lizations to the practice of human sacrifice may appear totally unacceptable from today’s perspective, as it might have appeared to European conquerors and friars. As quoted by Morales, “the cult to pagan gods, and the way it was practiced in such a complex religion… [struck] friars not only [as] weird, but also abominable….”17

Once definitively established in Mesoamerica, Span-ish conquerors and friars launched a long-lasting cul-tural conquest that gradually erased all traces of Aztec society and history, including the destruction of almost all codices and the burial of temples and entire cities.18 Fortunately, some archeological remains of the rich Mesoamerican tradition survived through codices kept by friars; today we can combine these sources with the information available from osteological collections to recreate the processes of decapitation and fabrication of

human skull masks. Understanding pre-Columbian Me-soamerican religions can only be realized by considering them in their own time and according to their own per-spective. For this reason, we tried to provide the reader with a glance into this culture’s cosmogonies. These civi-lizations lived in an extremely dangerous world, marked by almost constant war among tribes, and suffered natu-ral disasters without actually understanding them. Nega-tive effects of war and nature on society were what they feared most, and due to the impossibility of predicting or modifying their negative effects and influences, a very complex religious system emerged, based on war and na-ture deities. The cult of these gods and its practices, such as human sacrifice, tried to establish communication with divine forces and secure their favor. From their perspec-tive, intimacy with gods through worship would have helped these ancient societies exert some effects on fertil-ity, maize rising, rain, and other events of extraordinary importance for their daily lives.12 According to Aztec mythology, life and natural forces arose from the buried bodies of the sacrificed gods. The people of Tenochtitlan believed that human sacrifice was a sort of payment of human debt to the gods for their own lives, which were made possible through the sacrifice that the gods had pre-viously made for them.3

Despite its evident religious roots, the practice of human sacrifice, and especially decapitation, must have involved certain technical nuances that required a good level of anatomical knowledge.5 Although neurosurgery was not yet a developed surgical technique,8 archeologi-cal findings suggest the existence of what can be seen as a primitive form of skull base dissection among Aztec priests. Because they had to train in a specialized educa-tional system,3 these priests learned not only a standard-ized surgical technique, but also a body of anatomical knowledge and the uses of specialized surgical instru-ments. It is uncertain whether the body of knowledge

Fig. 3. Images demonstrating aspects of the skull mask fabrication technique. Left: Once the scalp was removed and the temporal muscle was elevated, the first step involved fracture and removal of the temporal squama (shaded area 1). Second, the parietals, occipital, and posterior part of the temporal bones were removed by bending the bony edges and by abrasion methods (shaded area 2). The third step involved abrasion of the lower and middle clivus (shaded area 3). Finally, some objects and materi-als were encrusted within the orbital, oral, and nasal cavities (4). Right: Skull mask ornamented by this method. Reproduced with permission from the National Institute of Anthropology and History (INAH).

Fig. 4.  Precolumbine Mesoamerican figurines possibly showing ex-amples of skull base pathologies. Left: Ceramic mask (Totonac civili-zation, 14th century) showing a right orbital tumor. Right: Stone anvil (Totonac civilization, 14th century) depicting right-side facial paralysis. Note the deviation of contralateral structures. Reproduced with permis-sion from the National Institute of Anthropology and History (INAH).

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emerging from decapitation might have enriched the practice of medicine among Aztecs, given that physicians (ticitl) constituted a different profession, but there is evi-dence of interest in skull base pathologies among Aztec physicians as well.

ConclusionsSeveral contributions to medical practice might have

arisen from anatomical knowledge emerging from hu-man sacrifice and decapitation techniques in ancient Me-soamerica. The widespread use of these practices among these ancient civilizations suggests their high symbolic value. Based on the existence of a specialized caste of doctors and priests, we can hypothesize about the level of expertise they might have achieved through the continu-ous practice of these early stepwise skull base surgical procedures.

Disclosure

The authors report no conflict of interest concerning the mate-rials or methods used in this study or the findings specified in this paper.

Author contributions to the study and manuscript prepara-tion include the following. Conception and design: Lopez-Serna, Arriada-Mendicoa, Romero-Vargas, Ramos-Peek, Celis-Lopez, Revuelta-Gutierrez, Portocarrero-Ortiz. Acquisition of data: Lopez-Serna, Coll, Portocarrero-Ortiz. Analysis and interpretation of data: Lopez-Serna, Gomez-Amador, Coll, Romero-Vargas, Ramos-Peek, Celis-Lopez, Portocarrero-Ortiz. Drafting the article: Lopez-Serna. Critically revising the article: Lopez-Serna, Gomez-Amador, Coll, Arriada-Mendicoa, Romero-Vargas, Revuelta-Gutierrez, Portocarrero-Ortiz. Reviewed submitted version of manuscript: Lopez-Serna, Arriada-Mendicoa, Ramos-Peek, Celis-Lopez, Revuelta-Gutierrez, Portocarrero-Ortiz. Approved the final ver-sion of the manuscript on behalf of all authors: Lopez-Serna. Administrative/technical/material support: Lopez-Serna, Gomez-Amador. Study supervision: Gomez-Amador.

References

1. Bartelink EJ, Wright LE: Benign mandibular tumours: two case studies from the Maya lowland site of Tikal, Guatemala. Int J Osteoarchaeol 21:351–359, 2011

2. Benz BF, Cheng L, Leavitt SW, Eastoe C: El Riego and Early Maize Agricultural Evolution, in Staller J, Tykot RH, Benz BF (eds): Histories of Maize: Multidisciplinary Approaches to the Prehistory, Linguistics, Biogeography, Domestication, and Evolution of Maize. Waltham, MA: Academic Press, 2006, pp 73–80

3. Carrasco D: City of Sacrifice: The Aztec Empire and the Role of Violence in Civilization. Boston: Beacon Press, 2000

4. Chavez-Balderas X: Human Sacrifice and Mortuary Treat-ments in the Great Temple of Tenochtitlan. Mexico: Fun-dación para el Avance de los Estudios Mesoamericanos, 1997 pp 1–44

5. Demarest A: Overview: Mesoamerican human sacrifice in evolutionary perspective, in Boone EH, Benson BP (eds): Ritual Human Sacrifice in Mesoamerica. Washington, DC: Dumbarton Oaks Research Library and Collection, 1984, pp 227–247

6. Duran FD, Heyden D: The History of the Indies of New Spain (Civilization of the American Indian Series) (au-thor’s transl). Norman, OK: University of Oklahoma Press, 1994, pp 1–68

7. Gonzalez Y: El sacrificio humano entre los mexicas. Mexico City: Fondo de Cultura Económica, 1985, pp 1–45

8. Goodrich JT, Ponce de Leon FC: Medical and surgical prac-tice as represented in cultural figures from the pre-conquest Mesoamerican territories. World Neurosurg 74:81–96, 2010

9. Graulich M: Ritos aztecas. Las fiestas de las veintenas. Mexico: Instituto Nacional Indigenista, 1999, pp 2–80

10. Haglund W, Sorg MH: Forensic Taphonomy: The Postmor-tem Fate of Human Remains. Boca Raton, FL: CRC Press, 1997, pp 201–222

11. Hassig R: Aztec Warfare: Imperial Expansion and Politi-cal Control. Norman, OK: University of Oklahoma Press, 1995, pp 5–13

12. Hubert H, Mauss M: Essai sur la nature et la fonction du sac-rifice, in Mélanges d’histoire des Religions. París: Ancienne Librairie Germer Balliere et C, 1971, pp 1–130

13. Johannessen S, Hastorf CA (eds): Corn and Culture in the Prehistoric New World. Boulder, CO: Westview Press, 1994, pp 5–22

14. Kirchhoff P: Mesoamérica. Sus límites geográficos, com-posición étnica y caracteres culturales. Xalapa, Mexico: Al Fin Liebre Ediciones Digitales, 2009, pp 2–12

15. Markman PT, Markman RH: Masks of the Spirit: Image and Metaphor in Mesoamerica. Berkeley, CA: University of California Press, 1990, pp 95–96

16. Marlowe F: Hunter-gatherers and human evolution. Evol Anth 14:54–67, 2005

17. Morales F: Franciscanos y mundo religioso en México. Mexico City: UNAM, 1993, pp 4–18

18. Prescott WH: The History of the Conquest of Mexico. New York: Modern Library, 1998, pp 7–14

19. Romero J: Dental mutilation, trephination and cranial defor-mation, in Stewart TD (ed): Handbook of Middle American Indians: Physical Anthropology. Austin, TX: University of Texas Press, 1970, pp 50–67

20. Romero-Vargas S, Ruiz-Sandoval JL, Sotomayor-González A, Revuelta-Gutiérrez R, Celis-López MA, Gómez-Amador JL, et al: A look at Mayan artificial cranial deformation prac-tices: morphological and cultural aspects. Neurosurg Focus 29(6):E2, 2010

Manuscript submitted April 7, 2012. Accepted June 7, 2012.Please include this information when citing this paper: DOI:

10.3171/2012.6.FOCUS12120. Address correspondence to: Raul Lopez-Serna, M.D., Depart-

ment of Neurosurgery, Instituto Nacional de Neurologia y Neuro-cirugia, Av. Insurgentes Sur 3877, Col. La Fama, C.P. 14269, Tlal-pan, Mexico City , Mexico. email: [email protected]

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