Sedimentary rocks, however, usually cannot be dated by radiometric methods but must be dated by reference to associated igneous rock formations. Various methods of radiometric dating often do not agree, however, and it is not uncommon for results fitting a current view of prehistory to be accepted while other results are rejected. Disputes among anthropologists are not unusual. The problems of radiometric dating methods will be considered in some detail in Chapter-8 . Interpretation by associated cultural remains.
Man is the only cultural being.
Thus associated cultural remains should serve to distinguish human from animal fossils, provided that it is possible unmistakably to connect the fossil with the cultural materials. Stone and bone tools and evidences of the controlled use of fire, as well as signs of living areas, are important remains used by anthropologists to identify fossil men and to distinguish among their varying cultures. Many fossils have no associated cultural remains, and often there is no necessary connection between a fossil and stone implements found nearby. Assemblages of stone implements and fire sites located in ancient living floor areas reveal many things about the culture of ancient races of men, but these are often found without human fossils. Some of the modern type human skulls have been uncovered with no associated cultural remains.