This exercise is from an upper-division course for geology majors and minors, however, interested students from all disciplines who have satisfied the prerequisites are welcome. The prerequisite is the introductory physical geology course; having the earth history course is desirable but not required. The course has a required three-hour laboratory and two weekend field trips.

Although this exercise is taken from a paleontology class, it can be adapted for any intermediate or advanced classes on any topic. It can also work for introductory classes with motivated students. Repeated exposure increases effectiveness.

For this particular assignment

A basic understanding of taphonomy
A basic understanding of biostratrigraphy, including concepts like Signor-Lipps
Background on the K-T extinction and subsequent recovery

However, different reading topics would require different skills or concepts.

This is a stand-alone exercise, but it dovetails well with lecture units on taphonomy, extinction, extinction recovery, and testing hypotheses. Again, different reading topics would match up better with other lecture units. Whatever the topic, the exercise serves as continuing practice on reading, understanding, and synthesizing material from the primary literature. Perhaps most importantly, it serves to demonstrate the process of science and the changing understanding of issues over time.

For Bug Creek topic: Resolving complex evolutionary and taphonomic questions
For any topic: will vary by topic, but centers on understanding development of scientific understanding

Formulating new research questions

Practice reading and understanding primary literature
Practice clear and cogent writing

Right now I use four essay assignments in Paleontology. These assignments work to help students meet several goals of the course, including using reading/writing for critical thinking, synthesizing information from different sources, and formulating new research questions.

In particular, the last two of the four assignments are designed as part of a multi-step process. Each student is assigned a particular reading for which he or she will be the primary discussant in a class discussion. Two things are required to make this discussion work and to achieve the (hoped for) "aha" moments for the students.

Students must take the time to read and understand the paper they've received. It's useful, particularly if students are just starting out reading primary literature, to discuss how to approach reading a journal article. Maybe most important is inculcating the idea that most people don't read straight through a paper, that multiple readings are important, and that it's not like reading a novel – it takes time to absorb.
On discussion day, have students talk about the papers in chronological sequence. There should be back and forth discussion, of course, but when this process works right, (which is most of the time, in my experience), the stepwise introduction and discussion of the papers allows students to see how the problem was originally framed, how it developed, and how new information changes interpretations (and that there may not be a clear resolution).

After the discussion, hand out essay assignments tailored to the skills and knowledge you want them to acquire.

Evaluation is based on student performance in class and on the essay they turn in afterward. Discussion assessment is based on mastery of the material, ability to answer questions about the topic, and ability to integrate material with that of the other articles. Overall point value for discussion is low. The paper is worth more; however, not necessarily a lot more.

These are the Bug Creek articles assigned in this exercise; a different topic would require different articles.


Archibald, J. D. and W. A. Clemens. 1984. Mammal evolution near the Cretaceous-Tertiary boundary. In: W. A. Berggren and J. A. Van Couvering, (eds.) Catastrophes and Earth History; the new uniformitarianism. Princeton University Press, Princeton, N.J., p. 339-371.

Archibald, J. D., D. E. Fastovsky, and R. H. Dott. 1986. Comment and Reply on "Sedimentology, stratigraphy, and extinctions during the Cretaceous-Paleogene transition at Bug Creek, Montana. Geology 14(10):892-894.

Fastovsky, D. E., and R. H. Dott. 1986. Sedimentology, stratigraphy, and extinctions during the Cretaceous-Paleogene transition at Bug Creek, Montana. Geology 14:279-282.

Lofgren, D. L., C. L. Hotton, and A. C. Runkel. 1990. Reworking of Cretaceous dinosaurs into Paleocene channel deposits, upper Hell Creek Formation, Montana. Geology 18: 874-877.

Lofgren, D. L. 1995. The Bug Creek Problem and the Cretaceous-Tertiary Transition at McGuire Creek, Montana. University of California Publications in Geological Sciences 140. 185 pp.

Sloan, R. E., J. K. Rigby, L. M. V. Valen, and D. Gabriel. 1986. Gradual dinosaur extinction and simultaneous radiation in the Hell Creek Formation. Science 232(4750):629-633.

Sloan, R. E., and L. V. Valen. 1965. Cretaceous Mammals from Montana. Science 148(3667):220-227.

Smit, J., and S. Van Der Kaars. 1984. Terminal Cretaceous extinctions in the Hell Creek Area, Montana: Compatible with Catastrophic Extinction. Science 223(4641):1177-1179.