The Lefipán Formation ranges in age from the late Maastrichtian to the early Danian and preserves the Cretaceous-Paleogene boundary, though the exact layer is disturbed by bioturbation. The Danian section of the formation shows a remarkably rapid recovery from the extinction event, with aquatic plant taxa virtually undisturbed and other flora reappearing quickly. A layer in the formation, known as the "Turitella" bed, is considered closest to the onset of the Paleogene and the fossil of "Cocatherium", as well as the bivalve "Meretrix chalcedonica", was found approximately above the estimated K/Pg boundary. The formation has provided several macro- and microfossils of flora, which has led researchers to conclude the rapid recovery and low extinction rate of several genera and families of plants. Hemipteran insect predation on leaves is noted at levels slightly above the K/Pg boundary. While "Cocatherium" is the only mammal found in the formation, shark, and ray teeth of "Hypolophodon patagoniensis", occur in the Danian section and are indicative of a shallow marine to littoral (coastal) environment.