1) The amount of microscopic plankton in the oceans is staggering.
2)There never was a "dinosaur-to-oil" theory.
Certainly plankton produce large amounts of hydrocarbons, especially when compared with dinosaurs or any other large animal. However, given a single event that kills all life in the water column, how much gets deposited on the sea floor? Remember, these plankton require light to survive and are not, therefore, found at great depths. Most of the ocean is a vast desert with little life to be found. Shallow seas, of course are another matter,and I’m living on one here on the plains of Kansas. Still, hard to believe that three hundred feet or so of water above my farm could produce much oil from a one time event. Give it a few millions of years and its a different story.