New morphometric parameters for assessment of body size in the fossil freshwater crab assemblage from the Acheulian site of Gesher Benot Ya'aqov, Israel

The GBY pincer length data indicate that the broad size range seen in living populations of Potamon potamios also exists in the GBY fossil crabs. A minimum number of individuals (MNI) resulted in a very high density of 668 specimens (321 specimens per m3). In cluster analyses for each of the 22 parameters, the mean of the GBY crab population measurements is consistently smaller than that of the recent crabs, in which females display intermediate values and males are the largest. However, when allometry is also taken into consideration, cluster analysis groups together the recent males and the recent females and distinctly separates them from the GBY crabs. Further allometric analyses of fossil crab populations from earlier and later prehistoric sites in the northern Jordan Valley will enable a better understanding of the significance of these differences and possible evolutionary trends in the fossil crab population's taxonomy.