Research Methods

The primary focus of our research is on the use of vertebrate fossils to answer questions about the origins and evolutionary relationships of various taxonomic groups, the biology and geographical distribution of extinct organisms, and the development of ecosystems through time. Although we use a variety of different approaches, most of our projects loosely follow the seven-step process outlined below. Of course, research is often an untidy business, and doesn't necessarily proceed according to a well-ordered sequence; many of the "steps" may happen more or less simultaneously, but the overall structure still holds up approximately.

1. Think of a question worth investigating.

Sometimes this seems like the hardest step of all! Before beginning a project, we need a clearly defined objective, such as "to figure out which animals were the ancestors of turtles" or "to identify that weird skull we found last summer". The trick is to come up with a question that is interesting and hasn't already been conclusively settled, but that is also possible to answer using the resources we have available. Ideas for projects come from reading palaeontological papers, talking to other scientists, and sometimes finding a new specimen with unusual features that need explaining.

2. Get some specimens.

In practice, this sometimes precedes Step 1; for instance, it's quite common to find a fossil and then build a project around it. However, the fact remains that in order to do research in vertebrate palaeontology, it's necessary to start with one or more interesting fossils. Although we collect some of our specimens in the field, a majority of the material we study is actually borrowed from colleagues and from major collections at institutions such as the Royal Ontario Museum (Toronto), the Field Museum (Chicago), and the South African Museum (Cape Town). This approach allows us to obtain good fossils without having to spend all our time running around looking for them in African deserts and arctic wastelands! However, we do venture into the field occasionally, most recently in the German state of Thuringia (Corwin; see photo) and along the Mezen River in remote northern Russia (Robert). Field work can involve either looking for new fossil sites ("prospecting") or excavating ones that have already been located ("quarrying").

3. "Prepare" the fossils.

When a fossil first comes out of the ground, it's generally still encased in a layer of solid rock or hardened sediment, sometimes with just a single edge or surface of bone showing. Removing the surrounding rock (or "matrix") without damaging the specimen can be a difficult, delicate, and time consuming task. While some researchers prefer to use acids to dissolve the matrix, we normally prepare our fossils "mechanically" - by manually removing the rock with variety of tools. These include small air-driven jackhammers, rotating grinders similar to those used by dentists (for delicate work) and slender needles, sharpened on a grinding wheel, held in a pin-vise. Much of this work is done under a microscope, as many of the fossils we are studying belonged to animals the size of modern lizards or salamanders. Specimens are reinforced, and repaired when necessary (accidents will happen!) using an acetone-soluble glue called Vinac. Most of the preparation in our lab is carried out by Diane, our technician, though students generally complete whatever preparatory work is necessary for their own projects.

4. Describe and illustrate the specimens.

Before going on to consider more conceptual questions, it's usually necessary to draw and describe at least some of the fossil material used in the study - that way, the person reading the eventual publication has access to the basic facts about the fossils as well as our interpretations of them. Illustrations may be either photographs (usually black and white) or drawings; drawing takes longer, but often results in a clearer depiction of the specimen's important features. When preparing a drawing, we start by tracing the outline of the fossil using a nifty but simple device called a "camera lucida", which can be attached to a microscope to visually superimpose the drawing hand on the specimen. The outline is then shaded or stippled in to create a sense of depth. Many drawings in our papers depict specimens as they are actually preserved, whereas others (such as this drawing of the skull of a synapsid called Cotylorhynchus) are reconstructions of how parts of the skeleton might have appeared in the living animal. The written description complements the drawing by pointing out important features and often comparing them to other fossils.

5. Come up with some interpretations.

Having done the basic work of describing the fossils, it's now possible to go back and bring the information we've gathered to bear on the original question. At this stage it often becomes very important to consult previous publications on the same topic in order to fit our ideas into the context established by those of other scientists, and to gather additional facts that may be relevant to the problem. Sometimes interpreting the fossils is a matter of drawing inferences from their observed features ("It had flippers, so it was probably aquatic") while in other cases it may be possible to use software and statistical methods to help in the analysis. For instance, when evaluating the evolutionary relationships between fossil (or living) species, we often gather data about their anatomy and enter it, in numerical form, into "phylogenetic" computer programs such as PAUP and MacClade. These programs help us to determine what pattern of relationships best explains the distribution of anatomical features, and illustrate it using a diagram called a cladogram. We also dabble in morphometrics, the use of statistical methods such as principal component analysis to describe and compare the shapes of different fossils.

6. Write up and publish our results.

Once we have concluded our analysis, we concentrate on communicating the results to our colleagues. This usually involves publishing a paper in a scientific journal such as the Journal of Vertebrate Paleontology or the Canadian Journal of Earth Sciences. After we submit a paper, it is reviewed and criticized by two or more palaeontologists in order to evaluate its significance and catch any errors or omissions. The reviewers determine whether the paper is suitable for publication, and - if so - what changes and corrections may be required. This process of "peer-review" is considered highly important for maintaining accuracy in published scientific results.

7. Have a party.

Curiously, science educators at all levels often fail to tell their students about this crucial part of the scientific method...