Reconstructing the global radiation of Turdidae (Aves: Passeriformes) using explicit geographic ranges under two different palaeogeographic scenarios

The family Turdidae (Aves, Passeriformes) is a diverse clade of passerine birds that presents a global distribution across a wide range of environments. While numerous studies have addressed the biogeography of specific genera, the family's origins remain largely unresolved. To reconstruct this taxon's biogeographic history, we compiled genetic and geographic range data from public sources. This information was used to build a time-calibrated phylogeny based on a concatenated dataset of mitochondrial and nuclear genes for 155 species across 16 genera. Ancestral area reconstructions were performed using PhyGeo, a geographically explicit, diffusion-based method that integrates species distributions with a dynamic palaeogeographic model applied to a pixelated spherical model of the Earth. Our analysis produced contrasting results depending on model assumptions. Under the Global Model, which treats all land features as equally habitable, Turdidae likely originated in West Antarctica-South America, with later colonization of Africa, Australia, and Asia via an Antarctic route. In contrast, the Restricted Model, which excludes unglaciated Antarctic land, shifted the inferred origin to northern North America, placing ancestral ranges closer to extant distributions and more consistent with current evidence. These results underscore the importance of considering multiple lines of evidence and spatially explicit approaches when reconstructing biogeographic histories.