Leaf Description and Identification Tools

What is morphotyping and why do we do it?

When confronted with a group of fossils from an excavation, it is much easier to answer the questions "How many different species do I have in this collection?" or "What was the environment like?" than it is to answer the question, "Which species lived here?" The first two questions can be answered using a process called "morphotyping" and requires that you carefully observe the fossils and sort them into groups based on common characteristics. The third question requires that you need to know if any of the fossils have ever been described or named before. The first questions can be answered by a careful observer with a minimum of training while the last question requires a specialist with access to literature and the type specimens.

The process of sorting groups of unknown fossils into groups based on their characteristic features is known as morphotyping. In 1989, Kirk Johnson began to standardize the "morphotype method." Here's how it works. First, a collection of fossil plants is sorted into groups of similar morphology. Then, the best example of each group is designated as the holomorphotype (This is analogous to the type specimen of the Linnaean System but the big difference is that the morphotype system is informal and has common practices while the Linnaean System is formal and has laws. A holomorphotype, unlike a holotype, can be replaced by a better specimen). The holomorphotype is given a number that consists of two letters and three numbers (for example, PC105). This morphotype number then stands as an informal label for that holomorphotype specimen (and by comparison, all of the fossils in that group).

Once morphotyped, a flora can be analyzed to yield information about paleotemperature, paleorainfall, and floral diversity.