Early Cretaceous Angiosperm Radiation in Northeastern Gondwana: Insights from Island Biogeography Theory

The Early Cretaceous palynological successions record one of the earliest waves of angiosperm radiation in several low-latitude localities, including the Arabian Plate. The palynological analysis of 59 core and cuttings samples from the late Barremian–early Aptian Biyadh and Shu'aiba formations, offshore Saudi Arabia, reveals remarkably high angiosperm diversity. These Early Cretaceous angiosperms inhabited northeastern Gondwana together with a diverse flora that also included bryophytes, lycopodiopsids, ferns, conifers, and other gymnosperms. A review of the dispersal capacity of this Gondwanan flora suggests that most mainland taxa had potentially colonized the carbonate islands and island arc archipelagos on both sides of the Neotethys Ocean.