ABSTRACT
Silurian-Devonian marine biogeography is dominated until the Eifelian by a global subdivision into a widespread cool to cold climate realm that contrasts with warm conditions elsewhere. Following the Eifelian the global climatic gradient decreased markedly, resulting in the elimination of the cool to cold Malvinokaffric Realm. Laurentian marine faunas display a marked level of endemism through the Givetian, following which there is an overall cosmopolitanism through the remainder of the period.
