TESTS AND CONFIDENCE-INTERVALS FOR A COMMON UPPER END-POINT IN FOSSILTAXA

Statistical inference about the upper and lower endpoints of the strat igraphic ranges of fossil taxa can be based on the pattern of finds. S trauss and Sadler (1989) described a test and confidence interval for a common upper or lower endpoint in two or more taxa. This approach is conservative, in the sense that it provides only an upper bound on th e significance level. This paper describes and illustrates a test and confidence interval for which the significance level is known.