In article ,
Janet wrote:

Bones rot down in an active heap in between a few months and a few
years, depending on the size and age of the animal and whether the
bone was load-bearing. For example, the carcass and leg bones of
a chicken typically take 2 years, but the smaller bones disappear
within a year. The leg bones of a mature ox would probably take
the best part of 10 years, but lamb shanks take about 3-5.

My dog is still excavating the huge knuckle bones of mature ox which
she buried fresh up to 10 years ago. In her opinion they haven't
deteriorated at all.

Perhaps not. But that's not the point. The rate of decomposition
will depend a great deal on the biological activity, and a compost
heap is several times as active as even the top 6" of the soil.
Below that, the activity drops off rapidly.

That is why exhuming bodies from 6' down is still viable decades
on, whereas a body on the surface would be beyond most forensics.


Regards,
Nick Maclaren.