Abstract: The capacity to identify species and how they are distributed is fundamental to virtually every aspect of biological and conservation science. However, surprisingly little attention is generally afforded to taxonomic and systematic research. In recent years, molecular phylogenetics has fundamentally altered our understanding of the systematics and biogeography of scleractinian corals, revealing that traditional taxonomy used in most studies does not reflect species’ boundaries and evolutionary relationships. Here, we revisit the systematics and biogeography of the genus Acropora using an integrated approach combining morphological analysis and new genomic scale data from the targeted capture of ultra-conserved elements (UCEs) and exon loci, with careful comparison to the >400 nominal Acropora species. Preliminary analysis suggests that the true species richness of the family approaches or exceeds the number of nominal species; over three times the number of currently accepted species. This discrepancy arises because many species have been synonymised incorrectly, in addition to many undescribed species throughout the Indo-Pacific. Importantly, the geographic range size of the vast majority of species is far smaller than currently appreciated, with significant geographical sub-divisions within putative species (e.g. Acropora hyacinthus) and high rates of endemism in peripheral and high latitude assemblages. These findings dramatically alter assessments of relative extinction risk among Acropora species, and demonstrate the robust conservation relies on a robust taxonomy. Tom Bridge Biography: Tom Bridge is an Senior Research Fellow at the ARC Centre of Excellence for Coral Reef Studies at James Cook University and Senior Curator of Corals at the Queensland Museum Network, based at the Museum of Tropical Queensland campus in Townsville. His research is broadly focussed on the taxonomy, systematics, ecology, biogeography and evolution of corals, and how these factors influence ecosystem functions on coral reefs. Peter Cowman Biography: Peter Cowman is an ARC DECRA Fellow at the ARC Centre of Excellence for Coral Reef Studies. He is a previous recipient of the prestigious Donnelley Postdoctoral Environmental Fellowship (2014-2016) administered by the Yale Institute for Biospheric Studies (YIBS). Dr Cowman is a leading authority on the phylogenetic systematics and evolutionary origins of coral reef-associated fishes.