World of Dinosaurs/Taxonomy

Taxonomy is the study of categorizations. There are many ways that paleontologists have grouped and categorized animals in the past ~200 years of formal western-anglo-European-American paleontological practice.

Generally, both in this class and in today's American universities, folks say, "taxonomy" when they refer to hierarchical classifications that are built around animals' (extinct and extant) apparent physical traits and resemblances.

Today's paleontologists, particularly those that work on animals with bones, usually use cladistic analyses and phylogenetic approaches to group animals based on their shared evolutionary histories.

Consider how a person would answer the question below, using each of the three schemes presented.

"Which two things belong in the same category? Snail, Sea Urchin, Eagle."

Snail and Sea Urchin according to early Lineeaus work, and a late-century (1980s) taxonomy, and a phylogeny.

And again.

"Which two things belong in the same category? Lizard, Alligator, Eagle."

Lizard and Alligator according to early Lineeaus work, and a late-century (1980s) taxonomy, and a phylogeny.]

Growing up in the 1990s, Dr. Ritterbush was taught during science class to sort animals into groups, and to memorize the RANKS of these groups:

  • Kingdom
    • Phylum
      • Class
        • Order
          • Family
            • Genus
              • Species

We don't teach this scheme any more in college. Why? Well, the short answer is that these particular "ranks" are human constructs that look nice on paper, but don't have a strong link to real biological principals or processes. Exceptions include fossil studies that focus on Phyla, Families, and Genera, but these are a little too niche for this class. Please do chat with Ritterbush for more info.