Tertiary Charophytes from the Ogallala Formation of Ellis County, Kansas

Abstract

Four fossil charophytes, Amblyochara thomassonii Daily n. sp. Chara sadleri (Ung.) H. af R., Chara globularis Thuill. and Croftiella escheri (Ung.) H. af R., are described and illustrated. They were found in diatomaceous marl from the Ogallala Formation in Kansas at sites determined to be late Miocene-early Pliocene in age. This is the first systematic study of charophytes from the widespread late Tertiary Ogallala Formation of central North America. America, preliminary studies on some charophytes from the late Miocene-early Pliocene Ogallala Formation of western Ellis Co., Kans., are reported here. Although the presence of charophytes in the Ogallala Formation has been previously noted (Leonard and Franzen, 1944; Kiener, 1944), the charophytes in the present paper are the first to be described systematically. The second author first discovered them in 1973 while conducting research on fossil angiosperm endocarps, nutlets and anthoecia (Thomasson, 1976b). Subsequent samples were discovered and collected during 1974 and 1975. In this report, Thomasson discusses the geology and bio- stratigraphy and gives a revised age of the deposits. Daily provides the systematics.