A poster presentation at the Geological Society of America annual meeting in Portland last week presented evidence of more widespread charcoal in widely distributed Late Triassic sediments across northern Arizona. The authors, Lawrence Tanner and Spencer Lucas, conclude that wildfires were not uncommon and atmospheric oxygen levels had to have been higher than previously thought, likely at or above modern levels. [right, Triassic plant from Petrified Forest National Park. Credit, NPS]
The result is this "may be linked with the first appearance of mammals, and of pterosaurs and dinosaurs, whose evolutionary success likely resulted from their enhanced, oxygen intensive metabolisms."
Ref: FOSSIL CHARCOAL IN CHINLE GROUP STRATA (UPPER TRIASSIC), NORTHERN ARIZONA: DISTRIBUTION AND SIGNIFICANCE
TANNER, Lawrence H., Dept. Biological Sciences, Le Moyne College, 1419 Salt Springs Rd, Syracuse, NY 13214, tannerlh@lemoyne.edu and LUCAS, Spencer G., New Mexico Museum of Natural History, 1801 Mountain Road N.W, Albuquerque, NM 87104