The Miocene of western Nebraska

Merychyus calaminthus(Mammalia, Artiodactyla, Oreodontidae) of probable early late Arikareean (late Oligocene to late early Miocene) age from the lower part of the Chalk Canyon Formation, Maricopa and Yavapai counties, central Arizona

“…Peterson's (1907) action resulted in the inclusion of two superposed, faunally distinct, stratigraphic units in the Upper Harrison Beds. Schultz (1938) later replaced the name Upper Harrison Beds with Marsland Formation, in which he also included strata younger than the Upper Harrison Beds (Cook, 1965;McKenna, 1965). Schultz and Falkenbach (1940, 1947, 1950 referred to the Upper Harrison Beds as the lower Marsland Formation and to the younger strata as the upper Marsland Formation.…”

“…Successive species of the genus are distinguished from one another mostly by the relative degrees of retraction of their external narial openings and by the corresponding lengthening of their rostral premaxillary sutures. In order of decreasing age, these species include (1) M. carrikeri (Peterson, 1907) from the Upper Monroe Creek Beds of the CMNH (equal upper part of Monroe Creek Formation; assigned to Harrison Formation by Schultz andFalkenbach, 1949, 1950) and regarded herein as middle Arikareean (Ar2) in age; (2) M. vantasselensis (Peterson, 1907) Schultz andFalkenbach, 1949, 1954; include Lay Ranch Beds) and considered early late Arikareean (Ar3) in age in this report;…”

Geology of the Fort Laramie area, Platte and Goshen Counties, Wyoming

“…Hard dark-gray "pipy" (Schultz, 1941) limy sandstone concretions are present throughout this upper part. At some localities the upper part of the conglomerate sequence is predominantly gray massive fine-to medium-grained sandstone containing only scattered pebbles.…”

“…), Monroe Creek, Harrison, and the lower part of the Marsland formations of Nebraska (Schultz, 1938), as shown in table 2. Because of faulting, a single complete section of the formation is not exposed in the map area, but on the basis of known faunal horizons the total thickness of the Arikaree is estimated to be at least 700 feet.…”

“…They are oriented with the long axis parallel to the bedding plane and generally with a northeast trend. The limy concretions in the Arikaree formation are thought by Schultz (1941) to be the result of calcite precipitation from ground water flowing through the sands.…”