Rise and Fall of Species Occupancy in Cenozoic Fossil Mollusks

• Published in: Science (American Association for the Advancement of Science) Vol. 318; no. 5853; pp. 1131 - 1134
• Main Authors: Foote, Michael, Crampton, James S, Beu, Alan G, Marshall, Bruce A, Cooper, Roger A, Maxwell, Phillip A, Matcham, Iain
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 16-11-2007; The American Association for the Advancement of Science
• Subjects: Animals; Biodiversity; Biogeography; Biological Evolution; Biological taxonomies; Earth sciences; Earth, ocean, space; Ecology; Exact sciences and technology; Extinct species; Extinction, Biological; Fossils; Genera; Invertebrate paleontology; Marine ecology; Mollusca; Mollusks; Paleobiology; Paleoecology; Paleontology; Population Dynamics; Seawater; Species; Species extinction; Taxa; Time; New Zealand; mollusks; paleobiogeography; extinction; paleoecology; biogeography; Australasia; Invertebrata; Mollusca; Phanerozoic; Cenozoic; speciation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1146303

In the time between speciation and extinction, a species' ecological and biogeographic footprint--its occupancy--will vary in response to macroecological drivers and historical contingencies. Despite their importance for understanding macroecological processes, general patterns of long-term species occupancy remain largely unknown. We documented the occupancy histories of Cenozoic marine mollusks from New Zealand. For both genera and species, these show a distinct pattern of increase to relatively short-lived peak occupancy at mid-duration, followed by a decline toward extinction. Thus, species at greatest risk for extinction are those that have already been in decline for a substantial period of time. This pattern of protracted rise and fall stands in contrast to that of incumbency, insofar as species show no general tendency to stay near maximal occupancy once established.