Evolutionary Dynamics of Jurassic and Cretaceous Mammaliaforms in East Asia: A Phylogenetic Synthesis
1. Introduction: The East Asian Corridor of Mammalian Innovation The Tiaojishan and Djadochta Formations of East Asia serve as extraordinary "natural time capsules," offering unparalleled taxonomic resolution for the transition from stem-mammaliaforms to crown-group mammals. For decades, the prevailing consensus relegated Mesozoic mammals to the status of "small, nocturnal insectivores" occupying limited ecological space. However, the fossil record from these regions has systematically dismantled this stereotype, revealing a spectacular radiation of specialized ecomorphs—including the aquatic docodont Castorocauda , the subterranean Fruitafossor , and the gliding haramiyidans. These assemblages demonstrate that mammals had achieved high-fidelity niche specialization, mirroring modern ecological roles, tens of millions of years earlier than previously hypothesized. This review synthesizes the evolutionary trajectory between the specialized haramiyidan gliders of th...