Mass extinction triggered the early radiations of jawed vertebrates and their jawless relatives (gnathostomes).

ABSTRACT: Most vertebrate lineages are first recorded from the mid-Paleozoic, well after their Cambrian origin and Ordovician invertebrate biodiversification events. This delay has been poorly understood and is usually attributed to sampling and long ghost lineages. We analyzed newly compiled databases of Paleozoic vertebrate occurrences, biogeography, and ecosystems, revealing that the Late Ordovician Mass Extinction (~445 to 443 million years ago) triggered parallel, endemic radiations of jawed and related jawless vertebrates (gnathostomes) in isolated refugia. Postextinction ecosystems hosted the first definitive appearances of most major vertebrate lineages of the Paleozoic "Age of Fishes" (and today), following the loss of ubiquitous stem-cyclostome conodonts, nascent faunas of other gnathostom

SUBMITTER: Hagiwara W 

PROVIDER: S-EPMC12787538 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature