During what period did the mountain range in which Isoetes valida is primarily found first form?
Isoetes valida Isoetes valida, commonly known as the strong quillwort or true quillwort, is an aquatic pteridophyte native to eastern North America. It is found primarily in the Appalachian Mountains from Pennsylvania south to Alabama and Georgia. In addition, one collection of the plant was made in a railway ditch in Wilmington, Delaware in the 1860s, but this was most likely an accidental introduction.
Mauritanide Belt The Mauritanide Belt is an ancient orogen running parallel to the west coast of Africa from Morocco to Guinea-Bissau. The orogeny that formed the Mauritanide Belt was active between 320 and 270 million years ago in the Carboniferous and Permian. During this time period the eastern nappes of the belt thrusted over rocks of Devonian age in the Taoudeni Basin. During the Triassic the Mauritanide Belt was split from the Appalachian Mountains (with which it was previously a single orogen) as the Atlantic Ocean opened.