Out of the tropics, but how? Fossils, bridge species, and thermal ranges in the dynamics of the marine latitudinal diversity gradient.

ABSTRACT: Latitudinal diversity gradients are underlain by complex combinations of origination, extinction, and shifts in geographic distribution and therefore are best analyzed by integrating paleontological and neontological data. The fossil record of marine bivalves shows, in three successive late Cenozoic time slices, that most clades (operationally here, genera) tend to originate in the tropics and then expand out of the tropics (OTT) to higher latitudes while retaining their tropical presence. This OTT pattern is robust both to assumptions on the preservation potential of taxa and to taxonomic revisions of extant and fossil species. Range expansion of clades may occur via "bridge species," which violate climate-niche conservatism to bridge the tropical-temperate boundary in most OTT genera. Su

SUBMITTER: Jablonski D 

PROVIDER: S-EPMC3696828 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature