Identifying Fossil Shark Teeth

Upon completing this activity students should be able to:
- Describe sources of variation in fossil shark teeth
- Identify extinct species of sharks by their teeth
- Infer the geologic age of a sample based on fossil shark teeth

- A sample from Florida containing several hundred Miocene shark teeth.
- Geologic timescale
- Reference materials for identifying Miocene shark teeth

- Divide students into groups of two or three and give each group a handful of Miocene shark teeth (Figure 6) and
a geologic timescale. Tell the students the age of the shark teeth and have them locate the Miocene on the geologic
timescale. The University of California Museum of Paleontology has a good description of the Miocene Epoch
(http://www.ucmp.berkeley.edu/tertiary/mio.html).
- Have your students separate the shark teeth into (what they believe are) different species. Go around to each
group and assist with their sorting. Then have the students use the reference materials to name their fossil species.

- Figure 7 shows the most common fossils. For additional images and descriptions of common Miocene shark teeth, visit
- http://www.elasmo.com/frameMe.html?file=leecreek/leecreek.html&menu=bin/menu_leecreek-alt.html
- http://en.wikipedia.org/wiki/Megalodon
- http://www.ucmp.berkeley.edu/tertiary/mio.html
- http://www.science501.com/PTMiocene.html
- http://www.carlwozniak.com/earth/Miocene.html

Figure 7.
Common Miocene shark teeth.

(1) Carcharocles megalodon
(2) Carcharhinus sp.
(3) Galeocerdo aduncus
(4) Crocodile tooth
(5) Hemipristis serra upper lateral tooth
(6) Hemipristis serra lower lateral tooth
(7) eagle ray mouth plate
(8) Negaprion eurybathrodon
(9) Cosmopolotodus hastalis

Scale bars are one centimeter in length.
Figure 7 is from A Key to the Common
Genera of Neogene Shark Teeth by
Robert W. Purdy (pdf)