Birch Birch A birch is a thin-leaved deciduous hardwood tree of the genus Betula (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus "Betula" contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Green List of Threatened Species. They are a typically rather short-lived pioneer species widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates. Birch species are generally small to medium-sized trees or shrubs, mostly of northern temperate and boreal climates. The simple leaves
Mesoraphidiidae genera. Mesoraphidiidae are similar in overall appearance to modern snakefly species, having an elongated prothorax, giving a snake-like profile and from which the common name snakefly is derived. The family was likely tree-dwelling by nature, with larvae being active predators in trunks and branches. Female mesoraphidiids, where known and complete enough, have a long and densely annultated ovipositor which would have been used to lay eggs in crevices of bark. The family was restricted to the Northern Hemisphere, living in the warm temperate and paratropical forest belt that covered portions of Eurasia and North America. As currently described, Mesoraphidiidae contains