Geology of the Appalachians craton. The collisional belt spread into the Ozark-Ouachita region and through the Marathon Mountains area of Texas. Continent vs. continent collision raised the Appalachian-Ouachita chain to a lofty mountain range on the scale of the present-day Himalaya. The massive bulk of Pangea was completed near the end of the Paleozoic Era (Permian Period) when Africa (Gondwana) plowed into the continental agglomeration, with the Appalachian-Ouachita mountains near the core. Pangea began to break up about 220 million years ago, in the Early Mesozoic Era (Late Triassic Period). As Pangea rifted apart a new passive tectonic margin was born and the forces
Insect vertebrates could have been another factor. Most extinct orders of insects developed during the Permian period that began around 270 million years ago. Many of the early groups became extinct during the Permian-Triassic extinction event, the largest mass extinction in the history of the Earth, around 252 million years ago. The remarkably successful Hymenoptera appeared as long as 146 million years ago in the Cretaceous period, but achieved their wide diversity more recently in the Cenozoic era, which began 66 million years ago. A number of highly successful insect groups evolved in conjunction with flowering plants, a powerful illustration of