Preliminary Report on New Hominid Dental Tapho-Data, a New Taphonomic Hypothesis and Two New Taphonomic Ratios

The numbers of maxillary and of mandibular teeth represented in early hominid fossil assemblages, considered with data on maxillae and mandibles, suggest the hypothesis that, under bland depositional regimen, conditions of accumulation and survival of remains, upper and lower jaws and teeth stand a more or less equal chance of featuring in fossil collections. In a more exacting palaeo-ecological setting and unprotected potentially destructive taphonomic milieu, mandibular teeth and the sturdier lower jaws may be expected to be favoured over maxillary teeth and the more fragile maxillae. The ratio of maxillae to mandibles (Mx/Mn jaw ratio) and the ratio of maxillary to mandibular teeth (Mx/Mn dental ratio) are proposed as two new measures of the blandness or severity of the depositional and taphonomic milieux.