Controversies in Science/What killed the dinosaurs/A critique of Extended period of extinctions across the Cretaceous/Tertiary boundary in planktonic foraminifera of continental-shelf sections: Implications for impact and volcanism theories

(Review Paper) Cited in

Points Made
The extent of the spectrum of species extinction in and around the K/T boundary extends well before and after the Chicxulub impact boundary. Also, there were distinct extinction swells in periods both before and after the Chicxulub impact. The author seems extremely reliable in scientific knowledge, however she does not reach a clear conclusion for the cause of the mass extinctions explaining that there were most likely multiple variables and contributing factors to the scope of the extinction event.

Methods
The author examined plankton fossils both in Mexico and in Texas. These areas were chosen due to the close proximity of where the crater had landed. Also, Mexico and Texas had the most significant impact from the crater therefore, examining fossils from these areas would help determine exactly what happened.

Results
In the Mexican samples, only 26% of the species extinctions correspond with the K/T boundary and iridium band. In the Texas samples, no extinctions or animal changes appear to be correlated with the K/T boundary and iridium band.

The extinction at the K-T boundary is not completely compatible with the volcano or meteorite theories. Other causes should be considered.