Phanerozoic Land-Plant Diversity in North America

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Science  21 Dec 1979:
Vol. 206, Issue 4425, pp. 1400-1402
DOI: 10.1126/science.206.4425.1400


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.