Differential bone survivorship and ontogenetic development in guanaco (Lama guanicoe).

GONZALEZ MARIELA E.; ÁLVAREZ, MARÍA C.; MASSIGOGE, AGUSTINA; GUTIERREZ, MARÍA; KAUFMANN, CRISTIAN

International Journal of Osteoarchaeology

John Wiley & Sons, Ltd.

Año: 2012 p. 523 - 536

1047-482X

This paper presents the results of a taphonomic research program conducted over the past   five   years.   The   main   objective   of   the   program   is   to   investigate   differential survivorship   in   guanaco (Lama   guanicoe)   bones,   taking   into   account   the   ontogenetic development   of   this   species   and   the   densitometric   characteristics of   its   skeletal   parts. First,  density  analysis  was  carried  out  on  selected  bones  of  modern  individuals corresponding   to  different  age  classes.  Second, two experimental designs were conducted to explore the response of animal bone of different ages to weathering and fluvial transport. The first is a long term experiment that examines the deterioration of skeletal elements from a newborn, a juvenile and an adult modern guanaco exposed to sub-aerial weathering under controlled conditions. The second experiment examines the hydrodynamic sorting of dry and wet skeletal elements from a newborn, a juvenile, and an adult modern guanaco in an artificial flume under controlled current velocities (15 cm/s   and   30   cm/s). The main results of the research   program   indicate   that   immature bones have higher hydric transport potential and weather at a faster rate. We propose that  this  differential  bone  behaviour  is  partially  related  to  structural  density,  as demonstrated    by  density   analysis.  These  results  show   age-related biases in zooarchaeological assemblages affected by taphonomic processes.