On cliff faces are found pictures, sometimes incised but more usually painted, which are attributed to the Basketmakers. These usually show square-shouldered human figures or hand prints. The latter were normally made by dipping the hand in paint then placing it against the surface to be marked, but in some cases they were painted. The significance of these and later pictographs is not known, although there are innumerable theories. The most probable explanation seems to be that they had some religious significance but it is also possible that they were records, were designed to give information, or were done for amusement. [Illustration: Fig. 15—Modified-Basketmaker diorama in the Museum at Mesa Verde National Park. (Courtesy Mesa Verde National Park.)] THE MODIFIED-BASKETMAKER PERIOD[1] During the succeeding period, there was a continuation of the same basic culture, but there was great development and sufficiently important changes occurred to warrant recognition by the application of another name. The later phase is known as the _Modified-Basketmaker period_ or as _Basketmaker III_. Some archaeologists believe that the cultural changes were so great that it would have been better if the term “Basketmaker” had not been applied to both periods. The Modified Basketmaker period is marked by the beginning of a sedentary life and the establishment of regular communities. The essential continuity of the culture makes it difficult to assign specific dates to the period. A typical Basketmaker site is readily differentiated from a Modified Basketmaker site, but it is difficult to give a precise year for the time when the transition from one to the other occurred. The beginning is usually placed between 400 and 500 A. D. The earliest date yet established by tree-rings for a Modified-Basketmaker site is 475 A. D.[87] There is general agreement that, in most places, the Modified-Basketmaker period ended about 700 A. D., but some archaeologists place the terminal date as late as the ninth century for certain areas. One difficulty in trying to establish fixed dates for cultural phases is that change and development were not equal in all areas. Dates which may be correct for the main, or nuclear, area may be entirely incorrect if applied to peripheral regions where development was slower and fewer changes were made. During Modified Basketmaker times the San Juan drainage was still the nuclear area, but the culture was quite widespread and extended north into Utah, as far west as southwestern Nevada, and south to the Little Colorado in Arizona, and beyond Zuñi in New Mexico.