Understanding Evolution: your one-stop source for information on evolution
Resource library Teaching materials Evolution 101

Teaching materials : Image library:

To save: right-click (Windows) or control-click (Mac) on the image and select "Save image."

Analogies (1 of 3) Saberteeth

Image caption:
These skulls belong to extinct animals, and both of them have saberteeth — long, ferocious canines. Would you guess that these saberteeth are homologous — inherited from a common ancestor with extra-long saberteeth?

See the Understanding Evolution page where this image appears.

<< Back to search results

Image credit:
If you use this image in your own non-commercial project please credit it to the University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu).

This image is part of a series:

Analogies (2 of 3) Saberteeth
Despite their similarities, the unusual length of these teeth is NOT homologous. One skull belongs to Thylacosmilus, a marsupial mammal. The other belongs to Smilodon, the saber-toothed cat, which is a placental mammal. Marsupial and placental mammals are very different, and diverged from each other a long time ago on the evolutionary tree. Thylacosmilus is more closely related to other marsupials such as kangaroos and koalas than it is to Smilodon. Smilodon is more closely related to other placentals such as housecats and elephants than it is to Thylacosmilus. Saberteeth is not a common trait in the marsupials closely related to Thylacosmilus, or the placentals closely related to Smilodon.

Analogies (3 of 3) Saberteeth
As they weren't inherited from a common ancestor, the saberteeth in Smilodon and Thylacosmilus evolved independently from one another. That means that one lineage on one part of the tree of life evolved saberteeth from normal length teeth, and a different lineage somewhere else on the tree also evolved saberteeth from normal length teeth.