no RE. Clements 



In evaluating the Ricardo group, Webber (1933:134) states 

 that all the species are possibly identical with those living now 

 in the general region, but that difiFerencees in range justify their 

 assignment to the Pliocene. Today, the closest approach to the 

 grouping and the related climate is to be found in the San 

 Jacinto Range bordering the Colorado Desert, where palms 

 occur on the desert level, with pinyons and live oaks on the 

 slopes toward the desert. The conclusion is reached that the 

 climate was less extreme than that of the present desert. 



The evidence from the other Pliocene horizons of California 

 is indirect because these are much more northerly, except the 

 very scanty remains from the Pico of Ventura (Dorf, 1933:66). 

 The several floras show a close relationship to the living forests 

 of the region, modified somewhat by the effects of a major cli- 

 matic cycle. It is assumed that the climate of the Lower Pliocene 

 was rather drier and warmer than the present one, but that con- 

 ditions became cooler and more humid in the Upper Pliocene 

 than they are in the same districts today. Since the- Ricardo is 

 regarded as Lower Pliocene, it is clear that the conclusions are 

 not in accord, though this discrepancy may be explained by 

 topographic control. However, there is distinct agreement that 

 the climate of California was drier throughout the Pliocene 

 than during the Miocene. 



