RT Journal Article SR Electronic T1 Discovery of Cretaceous Mammalia JF American Journal of Science JO Am J Sci FD American Journal of Science SP 81 OP 92 DO 10.2475/ajs.s3-38.223.81 VO s3-38 IS 223 A1 Marsh, Othniel Charles YR 1889 UL http://www.ajsonline.org/content/s3-38/223/81.abstract AB