While brachiopods were abundant in warm, shallow seas during the Cretaceous period, they have been outcompeted by bivalves, and now live mainly in cold and low-light conditions.
Sementara brakiopoda berlimpah di laut hangat dan dangkal selama periode Kapur, mereka kalah berkompetisi dari bivalvia, dan sekarang tinggal terutama dalam kondisi dingin dan cahaya gelap.