Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yacobucci, M. M. Search for Related Content GeoRef GeoRef Citation

Multifractal and white noise evolutionary dynamics in Jurassic–Cretaceous Ammonoidea

¹ Department of Geology, Bowling Green State University, 190 Overman Hall, Bowling Green, Ohio 43403-0218, USA

For more than a decade there has been interdisciplinary debate on whether fossil origination and extinction time series show evidence of self-organized criticality (SOC) or some other, more complex hierarchical structure. Analyses of a new data set of Jurassic and Cretaceous ammonoid genera demonstrate that these taxonomic subgroups do not reproduce the patterns seen in larger data sets that pool disparate taxa. Rather, originations and extinctions in these ammonoids show no evidence of SOC, limited evidence for a hierarchical multifractal pattern, and, at least within the suborder Ammonitina, evidence consistent with a white noise signal. Although a white noise pattern has been identified previously in an ammonoid family diversity time series, the significance of such a result for ammonoid genus originations and extinctions is discussed here for the first time. This white noise pattern indicates that processes acting on short time scales (less than a few million years) dominate the Ammonitina origination and extinction records, producing a nonhierarchical diversity dynamic. Because origination events in one interval do not appear to trigger originations in subsequent intervals, ammonite evolutionary radiations were likely to be extremely rapid and driven by physical rather than biological opportunities for diversification.

Key Words: Mesozoic • evolution • extinction • ammonoids • self-similarity

This article has been cited by other articles:

				P. C. Fitzgerald and S. J. Carlson Examining the latitudinal diversity gradient in Paleozoic terebratulide brachiopods: should singleton data be removed? Paleobiology, September 1, 2006; 32(3): 367 - 386. [Abstract] [Full Text] [PDF]