Species diversity
Conodonts were moderately affected by the event, with different regions varying in the number of species lost. Pelagic conodonts had a total species extinction rate of about 40%, with some areas have a local rate as high as 72%. About 50% of neritic conodont species died out, with survivors characterized by their wide distribution and versatile ecology. Species diversity rebounded soon afterwards, returning close to pre-extinction levels by the middle of the Tournaisian. The Hangenberg Event has also been implicated in the final extinction of several agnathan (jawless fish) groups.