The ammonoids, which had been in a long-term decline for the 30 million years since the Roadian (middle Permian), suffered a selective extinction pulse 10 million years before the main event, at the end of the Capitanian stage.
Os amonoideos, que estaban experimentando un declive a longo prazo durante 30 Ma desde o Roadiano (Permiano medio), sufriron un pulso de extinción selectiva 10 Ma antes do evento principal, ao final do piso Capitaniano.