Deccan Continental Flood Basalt Eruption Terminated Indian Dinosaurs before the Cretaceous-Paleogene Boundary

Abstract

Abstract: Late Cretaceous-Early Paleogene sediments associated with Deccan Continental Flood Basalt (DCFB) sequences of central and western India record the timing of the introduction and extinction of Late Cretaceous dinosaurs in India based on magnetostratigraphy and magnetic susceptibility stratigraphy. Current taxonomy indicates that only two genera of titanosaurs (e.g., Isisaurus and Jainosaurus), at least four species of large-bodied abelisauridae theropods (e.g., Rajasaurus narmadensis, Rahiolisaurus gujaratensis, Indosuchus matleyi and Indosaurus raptorius) and a small-bodied theropod Laevisuchus inhabited India during the Maastrichtian. Their stratigraphic and geographic distribution suggests that these dinosaurs were dominated by titanosauriforme and abelisauridae that first appeared before the advent of Deccan volcanism in the magnetochron C30n and were well established with the acme of breeding and nesting during C30n to maastrichtian C29r. Their decline in diversity and abundance coincides with initiation of DCFB eruptions when most of the early taxa were terminated and only a few titanosauriforme sauropods survived becoming extinct at about 350 kyr before the Cretaceous-Paleogene boundary (KPB). Dinosaur extinction in India is thus directly tied to Deccan volcanism with no evidence of an asteroid impact.