This is the second post by this semester's student volunteers on bioarchaeological research at Calixtlahuaca.
This post includes photographs of human bone.
By Kea Warren
Bioarchaeologists
work with the traditional archaeologists to try to understand the way a group
of people lived based on the remains they leave behind. While working on the site of Calixtlahuaca in
Mexico, Doctor Michael Smith and his team uncovered four full burials and the areas
with broken bone rasps discussed in the previous post, all of which were later
analyzed by Kristin Nado. Six burials is a relatively small sample size. While
the site provides insight to the lives of a small group of people,
archaeologists tend to prefer larger samples to understand trends and diversity
among the population. From this smaller sample, bioarchaeologists can observe
individuals and how those individuals lived, as will be discussed later, though
the broader understanding of the group is limited.
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| Map of Burial Locations |
Three burials are physically close
together, which may imply some sort of familial relationship between burials 5,
4, and 3 (which contain two adult males and an adult whose sex is
unknown). The two of these three bodies
with preserved feet share a congenital condition known as non-osseous tarsal
coalitions. This condition is also found in burial 2, which is from a different
house excavation. According to Nado,
tarsal coalitions are when two or more tarsal bones are connected by bone or
cartilage. This union of bone can be painful, and can also affect the
sufferer’s ability to walk. Further
study of the inhabitants of Calixtlahuaca would provide a better understanding
this condition in the region. If other remains were uncovered, it would allow
bioarchaeologists like Nado to analyze if the condition is regional or possibly
only specific to certain groups. DNA evidence of the relationship would
strengthen the claim.
Beyond this potential familial
relationship, the man in Burial Four has pathologies that are not found in the
other burials.
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| Burial 4 |
Burial
Four is a male, who was between 25 and 29 years old at the time of death. Based
on the man’s bones, Nado could immediately identify several pathological
problems that give insight into the life of this man. The tarsal coalitions are present, which would
probably have caused pain. The lip of his acetabulum (colloquially known as the
hip joint) appears to have extra articular surfaces. Nado has hypothesized that
this may be due to a dislocation of the hip earlier in his life that was never
realigned. This would have been
extremely painful, if not completely crippling to individual in Burial Four. The
injury was sustained long enough before death that the bone had time to repair
itself and try to accommodate the new location of Burial Four’s femur. This
would have taken years.
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| Cyst in Burial 4's femur |
His left tibia is also of
interest. It is unlike any other long
bone found on site. Inside normal long bones is the medullary cavity, where the
marrow is found. In Burial Four’s tibia, there seems to be a bubble of bone.
The bioarchaeologists of SHESC remain puzzled as to what it could be, though it
has been suggested that a cyst in the bone ossified, and that this is what
remains.
More
can be learned from his skeletal remains. The teeth on the left side of his
mouth are significantly more worn than those on the right, which Nado has
suggested may have been due to use of his teeth for things beyond chewing. Was
this for some task he performed because he could not walk? Only Burial Five had a similar, albeit less
prominent, wear pattern, also known as “bilateral asymmetry”. If more
mandibles/maxilla can found at the site, more research into the presence of
this wear could be performed. Was it specific to a group or family? What caused
it? What does this tell us about social organization at the site and the
relationship between Burial Four and others of his time?
While
not everything that happened in life can be viewed in the skeletal remains of a
person, bioarchaeology offers a glimpse into the lives of those long gone. Thanks to Dr. Michael Smith, Angela Huster,
Juliana Novic, Kristin Nado and the Calixtlahuaca team for their efforts to
discover more about how people lived long ago.
