31. Several fossils have been discovered from the Early ( Lower ) Devonian Period of Tillywhandland, Scotland. 32. Chagrin shale, is blue gray in color, an offshore alluvial, silt shale of the Devonian period . 33. During the ensuing Devonian period , the sea returned to southern Minnesota and local sediment deposition resumed. 34. The region's rocks were laid down in the Devonian period and are known as Rhenish Facies. 35. These are in part overlain by Old Red Sandstone rocks formed later in the Devonian period . 36. The first ammonites also appeared during or slightly before the early Devonian Period around 400 Mya. 37. Limestone shelves along the lake shore contain the fossils of marine animals from the Devonian period . 38. These sedimentary rocks are from the Devonian period , laid down 395 to 345 million years ago. 39. The sedimentary rocks in Montour County are from either the Devonian Period or the Silurian Period. 40. The Taunus range originated during the Devonian period .
