在隔了一年后,马什重新组织了考古团队再次回到堪萨斯州,这次由马什的学生Thomas H. Russell发现到了接近完整的黄昏鸟化石。[10]这具样本上完整地保留了黄昏鸟的头部,让马什惊讶的是,黄昏鸟的口中上下均具有牙齿。[11]在1873年,马什表示这些化石的发现,模糊了分隔鸟类与爬虫类的界线。[11]然而之后不久,部分挖掘到的化石样本却流到了爱德华·德林克·科普手上,成为引发“化石战争”的导火线。
Perrins, Christopher. Harrison, C.J.O. , 编. Birds: Their Life, Their Ways, Their World. Pleasantville, NY, US: Reader's Digest Association, Inc. 1987: 165–166 [1979]. ISBN 0895770652.
Holtz, Thomas R. Jr. (2011) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,Winter 2010 Appendix. (页面存档备份,存于互联网档案馆)
Charles Schuchert and Clara Mae LeVene, O.C. Marsh: Pioneer in Paleontology, p. 427. New York: Arno Press, 1978. Later, Russell assisted Marsh while attending medical school; he became a surgeon, professor of Clinical Surgery in the Yale School of Medicine, and Marsh's personal physician until Marsh's death in 1899. See Proceedings of the Connecticut State Medical Society (Google eBook) and Genealogical and Family History of the State of Connecticut: A Record of the Achievements of Her People in the Making of a Commonwealth and the Founding of a Nation. Editorial staff: William Richard Cutter, Edward Henry Clement, Samuel Hart, Mary Kingsbury Talcott, Frederick Bostwick, Ezra Scollay Stearns. Volume I (of 4). New York: Lewis Historical Publishing Company, 1911.