Figure F5. Leg 198 timescale and primary calcareous and siliceous microfossil datums for the Late Jurassic-Early Cretaceous (Gradstein et al., 1995, modified after Channell et al., 1995; and Baumgartner et al., 1995a; Erba et al., 1999; Premoli Silva and Sliter, 1999; A. Bartolini, pers. comm., 2001).