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

摘要: Abstract The faunal assemblage of Gesher Benot Ya'aqov (GBY) in the northern Jordan Valley, Israel, a waterlogged Early–Middle Pleistocene Acheulian site (0.79 Ma) correlated with Oxygen Isotope Stage (OIS) 20.2–18.2, includes over 5000 fragments (1–40 mm) fossil freshwater crab an undetermined species suspected to be Potamon sp., based on morphology its pincers. Most (92.6%) were identified body part, which 74.6% are crabs GBY demonstrate four distinct pincers, as is also typical present-day region, potamios. In this study we propose for first time series 22 easily measurable morphometric parameters that permit assessment pincer size from fragmented pincers (35.5% fragments). We assume length represents size, recent region. was restricted Area C layer V-6, yielded 91.6% found C. It has been significantly related ( r = 0.671 – 0.955 , P 0.0025 ). same measured comparison 208 specimens potamios, mainly resulted higher correlations 0.806 0.990 0.0002 Consequently, even if remains very fragmentary, it still possible reconstruct crab. Regression line equations given implicative tool future fragmentary data indicate broad range seen living populations potamios exists crabs. A minimum number individuals (MNI) high density 668 (321 per m3). cluster analyses each parameters, mean population measurements consistently smaller than crabs, females display intermediate values and males largest. However, when allometry taken into consideration, analysis groups together distinctly separates them Further allometric earlier later prehistoric sites Valley will enable better understanding significance these differences evolutionary trends population's taxonomy.