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PALEONTOLOGICAL ASSESSMENT <br />A paleontological assessment of the project area was made to ascertain the potential of <br />geologic units within the project area boundary to yield vertebrate fossils, including a review <br />of pertinent scientific literature and maps and an on -site reconnaissance of accessible outcrop <br />exposures within the project area. These activities were conducted by Carl Conner (GRI <br />Archeologist), Joshua A. Smith (GRI Paleontologist), and Lucas Pointkowski (GRI <br />Archeologist). The following summarizes our findings. <br />The Mesaverde Formation (also considered the Mesaverde Group) occurs within the <br />project area (Tweto, 1979) and is a collection of geologic units (formations and members) <br />recognized throughout its extent as assorted deltaic deposits formed along the <br />western/northwestern shoreline of the transgressing and regressing Western Interior Seaway <br />during Late Cretaceous time. The Mesaverde Formation contains an extensive variety of <br />lithologies including terrestrial sandstones, mudstones, and coals, and also nearshore marine <br />sandstones in the lower formations and members where the Mesaverde intertounges with <br />marine deposits of the Mancos Shale (Young 1955; Hettinger and Kirschbaum 2002; <br />Kirschbaum and Hettinger 2004). <br />Various geologic designations and nomenclature have historically been used for the <br />units in the Mesaverde due to the many depositional sequences preserved over several episodes <br />of Western Interior Seaway shoreline advance and retreat during the Late Cretaceous <br />(Papadopulos, 2008); in the project area (Figure 5), the Rollins Sandstone Member is the <br />lowest stratigraphic unit in the Mesaverde Formation, and the Ohio Creek Member is the <br />highest stratigraphic unit (Hettinger et al. 2002). Kirschbaum and Hettinger (2004) consider <br />the Rollins Sandstone a member of the Late Campanian Mount Garfield Formation (within the <br />larger Mesaverde Group), where it is stratigraphically the highest of a series of three nearshore <br />marine sandstones; these authors, along with others (Collins, 1976; Brownfield et al., 1999), <br />acknowledge the correlation of this unit with the Trout Creek Member (Fenneman and Gale, <br />1909) of the Iles Formation (Mesaverde Group) in the Grand Central Hogback area of Garfield <br />County, Colorado (Madden, 1989). Above the Rollins Formation in the project area are two <br />coal - bearing units, the Bowie Shale and Paonia Shale (in ascending order) of the Cameo - <br />Wheeler Coal Zone, and they are overlain by a thick (300+ feet) sandstone unit called the <br />"Barren Member"; these latter three units are mapped as members of the Williams Fork <br />Formation (Mesaverde Group) (Papadopulos 2008). <br />Fossils known from the Mesaverde Group include the remains of a wide variety of <br />early mammals, including species of multituberculates, primitive marsupials, and placentals, <br />and teeth from unknown therians which can not be classified as placental or marsupial based <br />on dental anatomy. Other fossils include: fishes including chondrichthians and osteichthians; <br />amphibians; reptiles including turtles, lizards, snakes, birds and crocodilians. Dinosaurs from <br />the Mesaverde include the more popularly known genera Edmontosaurus and Albertosaurus, <br />as well as champsosaurs, mosasaurs, plesiosaurs, pterosaurs, ornithischian and saurischian <br />dinosaurs (DeMar and Breithaupt 2006; DeMar and Breithaupt 2008). The marine units in the <br />31 <br />