Summary of the cited paper [1]:<p><i>> Sharks (Selachimorpha) are iconic marine predators that have survived multiple mass extinctions over geologic time. Their prolific fossil record is represented mainly by isolated shed teeth, which provide the basis for reconstructing deep time diversity changes affecting different selachimorph clades. </i><p><i>> Here, we use a geometric morphometric approach to comprehensively examine tooth morphologies in multiple shark lineages traversing the catastrophic end-Cretaceous mass extinction—this event terminated the Mesozoic Era 66 million years ago. </i><p><i>> Our results show that selachimorphs maintained virtually static levels of dental disparity in most of their constituent clades across the Cretaceous–Paleogene interval. </i><p><i>> Our principal discovery of overall static disparity indicates that selachimorphs experienced no demonstrable preextinction decline or eco-morphological turnover as postulated for other vertebrate groups. </i><p>Implications for humanity: maybe we should start building underwater cities for the next inevitable mass extinction.<p>[1] Tooth morphology elucidates shark evolution across the end-Cretaceous mass extinction
<a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001108" rel="nofollow">https://journals.plos.org/plosbiology/article?id=10.1371/jou...</a>