Hopping Hotspots Shaped the Global Biogeography and Diversification of Orectolobiform Sharks

ABSTRACT Aim In marine biogeography, many clades exhibit their greatest species richness in the Central Indo‐Pacific region, which includes the Indo‐Australian Archipelago. However, there is no consensus that this region was the ancestral cradle of clade's species richness. Orectolobiform sharks are a well‐known group of marine vertebrates that mostly inhabit the Central Indo‐Pacific region. By combining insights from molecular phylogeny and the fossil record, we investigated the ancestral area of origin and likely evolutionary processes behind the global distribution of Orectolobiformes. Location Global marine realm. Taxon Sharks of the order Orectolobiformes (44 extant species). Methods We inferred their diversification dynamics using a Bayesian birth‐death skyline model with fossil occurrences combined with neontological data. We then tested biogeographical hypotheses with two probabilistic approaches: (1) the dispersal–extinction–cladogenesis (DEC) model with time‐dependent stratification informed by global palaeogeography and fossil constraints, and (2) the dispersal–extinction–sampling (DES) model estimating biogeographical processes through time. Results Diversification and biogeographical analyses indicate that Orectolobiformes originated in the Tethys Ocean during the Jurassic, where they diversified throughout the Mesozoic and early Cenozoic. This diversification was interrupted by a sudden extinction event of high magnitude corresponding to the Cretaceous‐Paleogene extinction. We recovered both high extinction rates in the late Eocene and high extirpation rates during the Cenozoic in the Tethys, which together contributed to shifting the centre of orectolobiform species richness from the Tethys Ocean to their current centre of diversity in the Central Indo‐Pacific. The DEC model estimated multiple southeastward dispersal events during the Oligocene‐Miocene, which led the Central Indo‐Pacific to become the new centre of orectolobiform diversity. Main Conclusions This study provides new empirical evidence supporting the hopping hotspot model of marine biogeography. The Tethys Ocean acted as a cradle of Orectolobiformes diversity throughout the Mesozoic and early Cenozoic. During the second half of the Cenozoic, the centre of orectolobiform diversity shifted to the Central Indo‐Pacific region, which acted both as an area preserving orectolobiform diversity and as a speciation pump. Finally, our results highlight the importance of using jointly neontological and palaeontological evidence as they provide complementary insights into the deep evolutionary past.