Hi Alex, I don't think I would trust it - just checked 4 sub-adult (distal unfused) R. norv. and they have it as well as all the adults, the paper says it is common in very old but safe for 'juveniles' whatever that means, so unless you have very young rats it seems not so good. The proportions of R.r are usually more slim for same length of femur, caput size smaller and other very subtle differences so you might be able to suggest which based on observations of a good range of specimens but I would be very cautious especially if no cranial available. 
SH-D ArchaeoZoology
On 23/06/2017 20:56, Alex Valenzuela wrote:
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Dear zooarchers, 

I was wondering if anyone has ever used the criterion described by Wolff et al. 1980 for the distinction between black and brown rats femora. It is based on the location of the foramen nutricium in the medial side, next to the crista femoris. Has anyone tested their reliability?

Alternative ways to identify Rattus femora are also welcome.

Best wishes,


Wolff, P., B. Herzig-Straschil, and K. Bauer. "Rattus rattus (Linné 1758) und Rattus norvegicus (Berkenhout 1769) in Österreich und deren Unterscheidung an Schädel und postcranialem Skelett." Mitteilungen der Abteilung für Zoologie am Landesmuseum Joanneum 9 (1980): 141-188.


Alejandro Valenzuela Oliver
PostDoc position 'Juan de la Cierva', Universitat de Barcelona

Equip de Recerca Arqueològica i Arqueomètrica, Universitat de Barcelona (ERAAUB)
Departament d'Història i Arqueologia, 
Facultat de Geografia i Història
c/ Montalegre 6-8
08015 Barcelona
Telf. +34934037554