New remains of Mammuthus trogontherii from the Early Pleistocene Nihewan beds at Shanshenmiaozui, Hebei

Rich fossil materials of Mammuthus trogontherii have been recovered from a new locality, Shanshenmiaozui, in the Nihewan Basin during the past several years. The materials include the most complete juvenile mandible ever discovered and some postcranial bones of Mammuthus trogontherii. The geologic age of the fossil bearing strata is about 1.3 Ma based on the preliminary correlation with the neighboring Paleolithic site at Xiaochangliang. The new materials represent a form more primitive than the true woolly mammoth in the following aspects: relatively larger dp1, relatively lower lamellar frequency and thicker enamel layer. The postcranial bones are not very helpful in taxonomic determination and evolutionary assessment; this is probably mainly due to the long period of growth and remarkable ontogenetic variations.