After several month of passive reading and enjoying your CONCH-L the discussion about the subject
"when does a shell becomes a fossil"  enforced following statement.

From my geological point of view the earlier mentioned categories "fossil" and "subfossil" are correct,
but the fixing of a sharp time boundary (10 000 years ago) is quite artificial.

The term "fossil" should be used more precise for any remnants of organisms, which were part of a
habitat or became preserved in sediments of a certain depositional environment (both are elements of
the non time-related term "facies") and which is not existing anymore in the actual investigation area.

The more diffuse term "subfossil" usually is used for remnants of organisms buried in Holocene deposits
and have to be identically with animal or plant species/forms still living in other parts of the wourld in similar
environments. In most of the cases subfossil skeletons or other parts of the organisms (e.g. periostracum,
ligament) are not modified by early diagenetic processes, like recristallisation or mineralisation. Often but
not always "subfossils" are better preserved as "older fossils", if the taphonomic (after the death) or
seimentary depositional processes allowing a complete preservation.

Glueck Auf!
Thomas from Lower Saxony

Thomas Loeffler
Institut fuer Geologie und
Dynamik der Lithosphaere
Goldschmidtstr. 3
D-37077 Goettingen
GERMANY
E-mail: [log in to unmask]