The earliest fossil evidence of spiny feather (pinnate-leaved) palms from the K-Pg of Gondwana

Palms, a plant family that forms a major component of lowland tropical rainforests worldwide, are represented by a large number of fossils from Cenozoic sedimentary successions and K-Pg sediments of India, but no spiny palm has been reported from there to-date. Here, we report fossilized 'feather' (well-separated leaflets that are attached to a single leaf axis, similar to a feather) palm leaf specimens that bear spines from the latest Maastrichtian (Late Cretaceous)-earliest Danian (Early Paleocene) sediments of the Deccan Intertrappean beds of Madhya Pradesh, central India. They provide the first evidence that spiny pinnately-leaved palms were present in India during Chron 29R, which spans the K-Pg transition, and when the bulk of the subcontinent was still in the Southern Hemisphere. Other reliable records of pinnate palms are from the Northern Hemisphere (Europe) and are much younger (Eocene, Oligocene, and Miocene) than the fossils reported here. Although our data are limited, the new finds suggest that Cenozoic palm dispersal may be consistent with the "Out-of-India" hypothesis seen in several other plant groups. This report also provides new information on the distribution, diversification, and evolution of spiny palms in deep time. The evidence of fossilized spiny palms dating to the latest Cretaceous may link to a defense mechanism evolved as protection against predation from large herbivores, presumably dinosaurs.