The availability of nutrients and the quantity and quality of food at the base of food webs have largely been ignored in discussions of the Phanerozoic record of biodiversity. We examine the role of nutrient availability and phytoplankton stoichiometry (the relative proportions of inorganic nutrients to carbon) in the diversification of the marine biosphere. Nutrient availability and phytoplank...

Abstract Delicate impressions in lacustrine strata of the lower Permian (lower Cisuralian) Usclas Formation record ephemeral freezing equatorial Pangea. These sediments accumulated paleoequatorial and intramontane Lodève Basin (southern Massif Central, France) during peak icehouse conditions Late Paleozoic Ice Age. Experimental replication these features supports interpretation that they are ic...

Shifts in the taxonomic composition of Paleozoic communities are commomly ascribed to selective extinctions. Suppression realized speciation rates owing shrinkage available adaptive space (lowering potential niche number), even though unselective, results differential diversity losses, greatest losses being sustained by clades with highest and extinction (the high-turnover caldes). The resultin...

The Ancient Pacific Margin NATMAP project (Thompson et al., 2000) is a collaboration between the British Columbia Geological Survey Branch, the Geological Survey of Canada and the Yukon Geoscience Office. It aims to advance understanding of the Cordillera-long belt of complexly deformed pericratonic rocks that made up the Pacific margin of North America in Paleozoic to early Mesozoic time (Figu...