Biology Reference
In-Depth Information
easier to accomplish in the field. Further, blind tests of interobserver reliability have demon-
strated that even novice examiners can be trained to a near-perfect accuracy for identification
of marks on bone using just a hand lens and angled light (
White, 1992; Blumenschine et al.,
1996
).
The identification of human action on bone depends upon the recognition of patterns of
modification that are characteristic of, if not unique to, human behavior, including such
assemblage-level indicators as preferential selection and distribution of bones, and specific
patterns of marking and breakage (
Andrews and Cook, 1985
). Micromorphology of indi-
vidual marks, taken in combination with the macroscopic characteristics of modifications,
is essential in taphonomic analysis. The anatomical location, distribution, and morphology
are all equally significant in determining both the cause and the purpose of bone modifica-
tion (
Raemsch, 1993; Blumenschine et al., 1996
). Even when microscopically indistinguish-
able, patterns of preferential alteration of particular bones or particular areas on bone can
help to discern between disparate causative taphonomic processes (
Schrenk and Maguire,
1988
). “Diagnostically valuable contextual clues include the orientation of the mark with
respect to a specimen's long axis, the number of marks present on a specimen, and the mark's
location on a specimen in relation to anatomical landmarks, fracture features, and other
marks” (
Blumenschine et al., 1996
:494).
Certain taphonomic signatures can only be distinguished by a macro-level analysis of their
patterning and distribution (
Behrensmeyer et al., 1986; Schrenk and Maguire, 1988
). For
example, despite the striking microscopic similarities between trampled bone and bone
scored with stone tools, the placement of marks on the architecture of the bones and the
frequency of marks within the assemblage are reliable indicators of the origins of the mark-
ings. Trampled bones classically show a tendency toward multiple, shallow, parallel stria-
tions oriented transversely or obliquely to the long axis (
Behrensmeyer et al., 1986
), so that
when more than 70% of marks on long bones are oriented oblique to the long axis, it is likely
that the marks are due to trampling (
Shipman, 1988
:267).
To accurately interpret the taphonomy of an osteological assemblage, analysis must occur
on three levels, taken together: the individual morphology of each mark; the frequency and
distribution of marks as they represent the surface damage to each bone; and the pattern of
elemental representation and distribution of damage to the bones at the assemblage level
(
Schrenk and Maguire, 1988
). Similarly, the importance of distribution within a single skel-
eton has been amply demonstrated in the accurate diagnosis of pathological lesions (
Ortner,
2008
). The pattern of distribution of marks across the skeleton is no less important in tapho-
nomic analysis, and therefore, among the first tasks that must be performed is the careful
reassociation of each set of skeletal remains. Not only the patterning of damage, but also
the presence and absence of elements, can provide a wealth of information regarding peri-
mortem action and postmortem treatment of remains.
TAPHO
NOMY AND SKELETAL BIOLOGY: TWO CASE S
TUDIES
Bones in either forensic or archaeological contexts are likely to be altered by numerous
taphonomic agents. The signatures of various human and natural agents may intermingle,
overlap, and obscure interpretation. These modifications can either confuse or illuminate
