Volcano of classifying magmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant or inactive, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists. They use classifications which refer to a particular volcano's formative and eruptive processes and resulting shapes. There is no consensus among volcanologists on how to define an "active" volcano. The lifespan of a volcano can vary from months to several million years, making such a distinction sometimes
Extinct Birds Extinct Birds Extinct Birds (complete title: Extinct birds. An attempt to unite in one volume a short account of those Birds which have become extinct in historical times—that is, within the last six or seven hundred years. To which are added a few which still exist, but are on the verge of extinction.) is a book by Walter Rothschild which covers globally extinct and rare birds as well as hypothetical extinct species which include bird taxa whose existence is only based on written or oral reports or on paintings. The accounts of the extinct bird taxa are based on Rothschild's