Colorful small stone swallow shell fossil group Dimensions: 11.5cm long, 9.6cm wide Place of Origin: Liuzhou, Guangxi - China Period: Devonian Description: The shape is like the wings of a swallow, so the ancients called it "Shiyan". Shiyan is an extinct brachiopod that first appeared in the late Ordovician period about 450 million years ago. By the Devonian Period 405 million years ago, there was rapid development and a wide variety of species. Stone swallows mainly lived in warm shallow seas. They became extinct in the Late Jurassic and continued to exist for about 300 million years. There are stone swallow specimens on the front and back of this fossil, which is very beautiful.