The Chagatai language was a trade language.
The Otter Sandstone Formation is an obselete geological unit in England , now referred to as the Helsby Sandstone Formation .. Formation. Formation ( stratigraphy ). England. England. Helsby Sandstone Formation. Helsby Sandstone Formation. It preserves fossils dated to the Triassic , Anisian period .. Triassic. Triassic. Anisian. Anisian. fossils. fossils. period. Period ( geology )