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Dear Gill,
 
I don't think there is any question about the fact that on average M2s are larger than M1s, and this will affect all their measurements, including crown height and width. The point, however, is whether this difference is sufficient to distinguish the two teeth biometrically, when found isolated. In my view the answer to that question, on the basis of the work we did at West Cotton, is negative.  Of course, the largest M1/M2s in the range will obviously be M2s and the smallest M1/M2s will certainly be M1s. However, if we are intersted in looking at population trends I don't think that to operate in this way will provide a satisfactory solution to the problem. In fact I think that this solution would be worse than the problem. Size-wise the biometrical distributions would result to be completely biased, with the lower range of the M2s and the upper range of the M1s being completely omitted. Age-wise the problem would be less serious but the risk of a biased distribution would remain, as culling patterns may be related to animal size (whether this is associated with sex or not) and as consequence the neglection of certain size groups may also artificially obliterare some age groups.
 
By the way, the West Cotton material included very little goat so, despite the possible occurrence of the odd goat tooth cannot be discounted, the distribution provided in Fig.13 is unlikely to be much affected by the confusion generated by the mix of the two species. We did not attempt to identify the actual molars as this report was completed before the publication of the paper by Halstead et al. in JAS. And, in any case, identifications based on loose molars would have probably be insufficiently reliable.
 
Best wishes,
Umberto 
 

 
On 16 November 2011 10:19, Knowles <[log in to unmask]> wrote:

Dear Marian, Umberto, Simon and all,

 

I expect that for M1s and M2s which are at early tooth wear stages (unworn to ‘6A’ or ‘d’), especially if all the sample are sheep not goat, it might be possible to separate them on the basis of crown height, which is greater in M2 than M1. Does anyone have any data on this?

 

It’s the identification at early wear stages which is the most important for age interpretation.

 

A plot of wear stage against mesio-distal length at the occlusal surface would be interesting to see, and easy to record.

 

For the West Cotton early medieval sample, Fig. 13, only a small percentage would be wrongly identified, if all with max crown width of 7.8mm or more were taken as M2s.

 

Has anyone looked at M2s for separating sheep and goat, cf. Payne’s distinctions for M1 in early wear?

 

More questions than answers,

Gill Jones

 

Payne, S 1985. Morphological distinctions between the mandibular teeth of young sheep, Ovis, and young goats, Capra. Journal of Archaeological Science 12, 139-147.

 

From: Analysis of animal remains from archaeological sites [mailto:[log in to unmask]] On Behalf Of Umberto Albarella
Sent: 15 November 2011 22:08
To: [log in to unmask]
Subject: Re: [ZOOARCH] M1 and M2 from ovicaprine

 

Dear Marian,

 

in 1994 Simon Davis and I undertook the analysis of the animal bones from a medieval rural site in England, called West Cotton. As part of that work we did not attempt to distinguish lower M1s and M2s of sheep/goat but we rather measured the maximum crown width of all of them and then compared it with the same measurements of those M1s and M2s that could be identified on the basis of their position in the mandible (in several cases the mandible had to be prised apart for the measurement to be taken). The results showed that there was huge overlap in size between the two teeth, which we concluded suggested that the two could not be reliably identified, at least on size. The report can be dowloaded at the following webpage:

http://research.english-heritage.org.uk/report/?4589
and the results of that test can be found in Fig.13.

By the way that report was eventually published 16 years later, but using a shorter version which we had also prepared in 1994, and which was unedited. Here is the reference for anybody who might be interested:

 

Albarella U & Davis S. 2010. The animal bones. In A.Chapman (ed.). West Cotton, Raunds: a study of medieval settlement dynamics AD 450-1450, pp.516-37. Oxford: Oxbow Books.

 

Should anybody be able to suggest morphological differences to separate the two molars, like Marian, I'd be very grateful to hear. I have never managed to identify a reliable and consistent criterion, but would be delighted to find out that I have overlooked it.

 

Best wishes,

Umberto

 

 

On 14 November 2011 15:41, Marian Galindo <[log in to unmask]> wrote:

Dear colleagues,

does anyone know the morphological or metrical differences between lower M1 and M2 from ovicaprine? Is there any publications about this?

 

Thank you very much in advance,
Best,

 

Marian.




--

Umberto Albarella
Department of Archaeology
University of Sheffield
Northgate House
West Street
Sheffield S1 4ET
United Kingdom
Telephone: (+) 44 (0) 114 22 22 943
Fax: (+) 44 (0) 114 27 22 563
http://www.shef.ac.uk/archaeology/staff/albarella.html
For Zooarchaeology short course see:
http://shef.ac.uk/archaeology/research/zooarchaeology/short-course.html
For Archaeologists for Global Justice (AGJ) see:
http://www.shef.ac.uk/archaeology/global-justice.html

"only when the last tree has died and the last river been poisoned
and the last fish been caught we will realise we cannot eat money"

 




--

Umberto Albarella
Department of Archaeology
University of Sheffield
Northgate House
West Street
Sheffield S1 4ET
United Kingdom
Telephone: (+) 44 (0) 114 22 22 943
Fax: (+) 44 (0) 114 27 22 563
http://www.shef.ac.uk/archaeology/staff/albarella.html
For Zooarchaeology short course see:
http://shef.ac.uk/archaeology/research/zooarchaeology/short-course.html
For Archaeologists for Global Justice (AGJ) see:
http://www.shef.ac.uk/archaeology/global-justice.html

"only when the last tree has died and the last river been poisoned
and the last fish been caught we will realise we cannot eat money"