Alvarez, L., et al. June 6, 1980. Extraterrestrial cause for the Cretaceous-Tertiary extinction. Science, vol. 208, p. 1095. The original paper describing how an impact event may have killed the dinosaurs.
Penny, David, and Masami Hasegawa. June 5, 1997. The platypus put in its place. Nature, vol. 387, p. 549. DNA sequence analysis alters the placement of the platypus on the mammalian family tree.
Stebbins, G. Ledyard, and Francisco J. Ayala. August 28, 1981. Is a new evolutionary synthesis necessary? Science, vol. 213, p. 967. A classic paper placing rapid evolution in the framework of Darwinian gradualism.
Wilson, E. O. Spring 2000. Vanishing before our eyes. Time, Special Issue, vol. 155, no. 17, p. 28. Mass extinctions are happening right now.