Hello Ylva,


I think i saw something on fusion in rodents somewhere, possibly a
biological work. If i can remember i'll get the reference off to you.

I'm studying micro-faunal remains from archaeological medieval
archaeological contexts for my Dphil. Primarily i'm interested in how
they get into the archaeological record in teh first place, and what use
they are for palaeoecological reconstruction. The study includes all the
vertebrate classes, and this obviously includes a lot of rodents.
As for aging, i've not gone into much detail. The problem being, that
amphibians and reptiles don't alter their skeletal morphology as they
grow older, they just get bigger. the rate of growth depends on numerous
climatic and environemtal factors, thus they are either juvenile, young
or big and old.
When it comes to rodents there is also a problem. Some epiphysis fuse
quite early, before the rodent is weaned or just after, others take so
long that the animal rarely lives long enough for fusion to take place.
The distal end of the femur is a good example of the latter. In
addition, the distal end oif the femur is often so poorly fused it
probably detaches before the bone is recovered from the archaeological
record. So, if you have a number of individuals that have a fused distal
end of the femur, for example, then the appendicula elements are likely
to be from older individuals. I find that molar wear gives some
indication of the age of an individual, but again this is a qualitative,
as opposed to a quantitative measure (the incisors grow throughout the
life of the individual). Young, fairly old and older. Therefore, limited
or minimal tooth wear would suggest that they are quite young
individuals. I think Armitage and West used tooth wear evidence to
suggest that the rodents they recovered from a medieval well deposit in
Greyfriars, London were young, or younger individuals. Integrating this
information with the known ecology of rodents, they concluded that the
individuals might well have been young males expelled by from more
suitable environments searching in less ideal surroundings for new
territories. Individuals roaming into unknown environments are known to
be particularly susceptible to predation or accidental death.


I'd be really interested in knowing which species you have identified on
the site, what date it is and what kind of site it is, i.e. small
settlement, town or rural. In my studies there appears to be big
variations in the community structure of small vertebrates, dependent on
geographic location, environment and levels of human activity. As an
interesting point, do you have any Rattus rattus?

Yours Phil Piper