==========================+===============================+============== 3. Homo sapiens |Historic (bronze and iron) age.|Modern (e.g., modern man) | | |Neolithic ("recent stone") age |Postglacial | (carefully shaped and |but | polished stone implements) |prehistoric --------------------------+-------------------------------+-------------- 2. Homo primigenius |Upper Paleolithic ("ancient |Late Glacial (e.g., Neanderthal | stone") age (rough bone | man) | and stone implements, cave | | frescoes, bone carvings, | | etc.) | |Lower Paleolithic ("ancient |Middle Glacial | stone") age (rude stone | | implements of so-called | | "river man") | --------------------------+-------------------------------+-------------- 1. Early ancestral forms |Possibly some very crude |Early Glacial (e.g., Pithecanthropus | stone implements |and possibly erectus) | |late Tertiary --------------------------+-------------------------------+-------------- Of the early ancestral forms, that is, those which were rather distinctly man-apes, two will be very briefly referred to. One of these, known as _Pithecanthropus erectus_, was a remarkable creature whose partial skeleton, consisting of the upper part of a skull, lower jaw, several teeth, and a thigh bone, was found in early Quaternary deposits in Java in 1891. It was certainly a man-ape or possibly ape-man of low order, about 5-1/2 feet high. The skull has a low crown, very receding forehead, and prominent brow ridges, but the brain capacity is 850 cubic centimeters, as compared to 500 cubic centimeters in ordinary higher apes, and nearly 1,500 cubic centimeters in the average modern man. The very recently extinct very low-type aborigines of Tasmania had a skull capacity of 1,199 cubic centimeters. In 1907 the lower jaw of an anthropoid or manlike ape set with rather human teeth was found associated with very crude stone implements seventy-five feet below the surface in river-deposited sand in Germany. It is of either early or middle Glacial time and quite certainly represents a lower order creature than the oldest Paleolithic man as described below.