Frasnian

All Sources -
Updated Media sources (1) About encyclopedia.com content Print Topic Share Topic
views updated

Frasnian (Frasien)
1. An age in the Late Devonian Epoch, preceded by the Givetian (Middle Devonian), followed by the Famennian, and dated at 377.4–367 Ma ( Harland et al., 1989).

2. The name of the corresponding European stage, which is noted for the culmination of the first major radiation of the single-celled Foraminiferida and for the origin of important groups of goniatites, prolecanitids, goniatitids, and clymeniids. It is roughly contemporaneous with the Senecan (N. America) and part of the Condobolinian and Hervyan (Australia).

views updated

Frasnian A stage of the Devonian Period, about 385.3–374.5 Ma ago) that is noted for the culmination of the first major radiation of the single-celled Foraminiferida. The stage is the penultimate of seven. Three important groups of goniatites, the prolecanitids, goniatitids, and clymeniids arose during this stage.

views updated

Frasnian The penultimate of the seven stages of the Devonian Period, dated at about 374–367 Ma ago.