Planktivorous sharks - cretaceous convergence with modern filter-feeding rays
Modern sharks occupy marine ecosystems across the world but display little morphological diversity, being mostly streamlined predators. Vullo et al. describe a new species of shark from the late Cretaceous that shows that the lack of current variation is not due to limited morphological “exploration” in the past. Specifically, Aquilolamna milarcae displays many features similar to modern manta rays, notably long, slender fins and a mouth seemingly adapted to filter feeding, suggesting that it was planktivorous. This finding indicates both that elasmobranchs evolutionarily experimented with other forms and that the planktivorous “soarers” emerged in this group at least 30 million years earlier than previously recognized.
Vullo R, Frey E, Ifrim C, González MAG, Stinnesbeck EZ, Stinnesbeck W. (2021) Manta-like planktivorous sharks in Late Cretaceous oceans. Science 371( 6535), 1253-1256. DOI: 10.1126/science.abc1490