If such a global wildfire had occurred, as suggested by Melosh and others (see Wild Fires ) the effects would have devastated life on the continents. Most above ground biomass (plants and animals) would have been overcome by the fires. Some small animals could have survived by finding shelter (e.g. cracks in rocks and caves).
Even fresh water organisms would have been affected. The fire would have caused an increase in water temperature, ocean debris and a decrease in oxygen levels of the water. The debris composed of inorganic and organic matter from the burnt biomass on the surface. The decrease in oxygen levels would have been caused by a mass influx of dead organic matter. Dead organic matter in water becomes oxidized, thus removing oxygen from the water.