title: Phanerozoic land-plant diversity in north america.
abstract: A strong correlation exists between the outcrop area of nonmarine rocks deposited during a given geologic period and the observed vascular plant diversity for the same period; however, diversity residuals characteristic of certain periods may have underlying biological causes. Within-flora diversity changes through time indicate that stepwise increases in community species packing have accompanied major tracheophyte evolutionary innovations. Total and within-flora data suggest that the track of North American land-plant diversity has been similar in nature, but not in timing, to that inferred for marine invertebrates.
authors.forename: A H
authors.initials: AH
authors.lastname: Knoll
authors.forename: K J
authors.initials: KJ
authors.lastname: Niklas
authors.forename: B H
authors.initials: BH
authors.lastname: Tiffney