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Extreme ecosystem instability suppressed tropical dinosaur dominance for 30 million years.

ABSTRACT: A major unresolved aspect of the rise of dinosaurs is why early dinosaurs and their relatives were rare and species-poor at low paleolatitudes throughout the Late Triassic Period, a pattern persisting 30 million years after their origin and 10-15 million years after they became abundant and speciose at higher latitudes. New palynological, wildfire, organic carbon isotope, and atmospheric pCO2 data from early dinosaur-bearing strata of low paleolatitudes in western North America show that large, high-frequency, tightly correlated variations in ?(13)Corg and palynomorph ecotypes occurred within a context of elevated and increasing pCO2 and pervasive wildfires. Whereas pseudosuchian archosaur-dominated communities were able to persist in these same regions under rapidly fluctuating extreme climatic conditions until the end-Triassic, large-bodied, fast-growing tachymetabolic dinosaurian herbivores requiring greater resources were unable to adapt to unstable high CO2 environmental conditions of the Late Triassic.

SUBMITTER: Whiteside JH

PROVIDER: S-EPMC4491762 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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Extreme ecosystem instability suppressed tropical dinosaur dominance for 30 million years.

Whiteside Jessica H JH Lindström Sofie S Irmis Randall B RB Glasspool Ian J IJ Schaller Morgan F MF Dunlavey Maria M Nesbitt Sterling J SJ Smith Nathan D ND Turner Alan H AH

Proceedings of the National Academy of Sciences of the United States of America 20150615 26

A major unresolved aspect of the rise of dinosaurs is why early dinosaurs and their relatives were rare and species-poor at low paleolatitudes throughout the Late Triassic Period, a pattern persisting 30 million years after their origin and 10-15 million years after they became abundant and speciose at higher latitudes. New palynological, wildfire, organic carbon isotope, and atmospheric pCO2 data from early dinosaur-bearing strata of low paleolatitudes in western North America show that large, ...[more]

PMID: 26080428

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Extreme ecosystem instability suppressed tropical dinosaur dominance for 30 million years.

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Extreme ecosystem instability suppressed tropical dinosaur dominance for 30 million years.

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