Figure F5. Comparison of estimated ages of radiolarian zones (Sanfilippo and Nigrini, 1998) to age boundaries intercalibrated with magnetic reversal stratigraphy during Leg 199. Leg 199 studies resulted in the first intercalibration of magnetostratigraphy and low-latitude radiolarian biostratigraphy and have significantly improved zone boundary ages and ages of individual fossil first and last occurrences (see Nigrini et al., this volume).