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Julia, I have collected data on microhardness of bone from various anatomical locations. Microhardness is a useful 'probe' for local variations in bone mechanics but also gives a measure of the ability of a material to resist abrasive wear. Briefly, in bird bones you find that bone at the mid-diaphysis is 'harder' than toward the epiphyses. I'm pretty sure that similar trends have been observed in mammalian bone too. I would have thought that variations in cortical thickness and hardness interact to determine the rate of bone degradation. You can find my original paper on bone hardness at: http://jeb.biologists.org/cgi/content/abstract/198/1/209 Rgds, Richard Bonser Dr R.H.C. Bonser Lecturer in Biomimetics Centre for Biomimetics School of Construction Management and Engineering The University of Reading Engineering Building Whiteknights Reading, RG6 6AY UK Web: http://www.reading.ac.uk/biomim -----Original Message----- From: Analysis of animal remains from archaeological sites [mailto:[log in to unmask]]On Behalf Of Jude Higgins Sent: 29 April 2003 19:21 To: [log in to unmask] Subject: Re: [ZOOARCH] BONE PRESERVATION Julia, As you know, Lyman found that structural density affects natural taphonomic processes--bones of higher density will survive better than bones that are less dense. When I looked at bone density and regressed it against cortical wall thickness (for avian skeletal elements), I found that 47% of the variation in bulk density could be explained by cortical wall thickness. The thickness of the cortical wall in bones varies taxonomically (in birds so I'm assuming in other animals as well), as well as within each skeletal element. I'll just mention a few elemental variations that I found. For instance, with birds, the distal end of the tarsometatarsus is likely to be missing because the cortical wall becomes increasingly thinner toward that end, however, the third digit is likely to be preserved because the cortical wall is relatively thicker than that of the other digits. The femur is likely to be missing one or both ends because the cortical wall thins proximally and distally. The coracoid is likely to be missing the sternal end because of a thinning cortical wall. My work in this area has been only on birds (and they weren't domestic), but I can send you a copy of the paper if you'd like. --Jude Jude Higgins Department of Anthropology & Utah Museum of Natural History University of Utah Salt Lake City, UT 84102 [log in to unmask] > Is there any evidence for certain areas of bones being more susceptible to > degradation than others ? > > In particular is there any evidence for the differential preservation of > proximal and distal humeri of domestic mammals? > > Thanks in advance, > > Julia > > Julia Elise Cussans > Post-graduate research > Department of Archaeological Sciences > University of Bradford > [log in to unmask] > > ------------------------------------------------- > This mail sent through IMP: webmail.brad.ac.uk >