2022-05-10_GENERAL DOCUMENTS - M1993041

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48 include sharks, salt water crocodiles, ichthyosaurs, and both long and short necked plesiosaurs (Russell 1988) . Overlying the Granerous shale is the Greenhorn Limestone. The Greenhorn consists of bedded limestones separated by thin shales. i Elder (1987) reports that various species of ammonites, inoceramid clams, oysters, snails and a shark tooth, were found in Lykins Gulch about 4.5 miles south of Lyons. Similar marine invertebrate fossils are common elsewhere as reported by Kauffman (1977) . A few rare vertebrate fossils are also known from the Greenhorn Limestone, including short necked plesiosaurs from Kansas (Craggin 1688; Russell 1988) and a three-dimensional preserved fish specimen from near Pueblo (University of Southern Colorado collections) . Above the Greenhorn Limestone is the Carlile Shale. This shale, about 75 feet thick, erodes quickly and is poorly exposed in Dowe Flats. Marine fossils reported by Kauffman (1977) from elsewhere in Colorado include inoceramic clams, oysters, bryozoans, ammonites, snails, and invertebrate ubrrows. The Codell sandstone overlies the Carlile. It is only about 15 feet thick in the Lowe Flats area and was seen along the St. Vrain Supply Canal . Kauffman (1977) has reported marine invertebrate fossils from elsewhere in Colorado, including inoceramic clams, oysters, and invertebrate burrows. Lag deposits of sharks teeth and fish bones are also known in some areas. The Niobrara Formation overlies the Codell sandstone. This formation is divided into two members, the lower Fort Hays Limestone, about 20 feet thick in Dowe Flats and the upper Smoky Hill Shale, about 360 feet thick. The Niobrara Formation is the only formation mined at Dowe Flats, with the Fort Hays member being the source of limestone. In one of the few studies of the fossils form the Dowe Flats area, Barlow (1985) , lists the following fossils from the Southwest Portland Cement Quarry: invertebrate burrows