Evolution of Extinct Animals

1. Using the geological timescale, understand that animal life has existed for hundreds of millions of years on Earth.
2. Many major and successful groups of life are now extinct, and mass extinctions have played an important role in the extinction of many of these successful groups of animals. These extinctions have also allowed geologists to use the fossil record to tell time.
3. Use diversity curves to interpret how diversity has changed through time in different groups of animals.
4. Research what ancient animals looked like, how they lived, and during what time they were important components of life on Earth.
5. Life has evolved throughout millions of years and extant (currently living) life is composed of a small portion of the enormous biodiversity observed throughout the history of life.

1. Download and analyze data from large scientific databases, and interpret the graphical results to understand how historical events (such as extinctions) have affected biodiversity.
2. By comparing results with those generated by other students, critically evaluate how animal life has evolved through geological time.
3. Use data to formulate hypotheses for how mass extinctions can impact life, including, by extension, the current mass extinction.

1. Working in groups, use computers to search the Paleobiology Database to compile and download appropriate diversity data.
2. Orally communicate interpretations with other students.

The primary foci of the activity is on introducing students to geological time and fossil animal groups, and using them to understand the importance of mass extinctions in life's history. (By extension, students can hypothesize how a current "sixth mass extinction" could affect life.)

The activity is flexible and easily can be modified as a short within-class activity through a major class project incorporating group presentations.

For Parts I and III, student groups will need access to a computer (with internet access) and a printer.

Several of the questions in this activity are open-ended and intended to promote discussion. As a result, these questions do not have specific right or wrong answers. Also, because the Paleobiology Database is continuously updated with new fossil data, the answers for certain questions (such as the time intervals of first and last appearance in the fossil record) may change from one year to the next.

It is important that student group pick different animal groups. If using only a few groups, it will be worthwhile to assign groups so that representatives of Paleozoic and Mesozoic animal groups are covered. (Especially good choices include rugose corals, trilobites, strophomenate brachiopods, crinoids, ammonites, and plesiosaurs. The last page of the activity briefly lists the era each group existed.) Other groups could be chosen if students are especially interested; just make sure the group is extinct (or nearly so) and has a good fossil record during at least some time in the last 542 million years.

Parts I and II could be assigned as homework to spend more time on subsequent parts during class.

For a short (<50 minute) activity, consider the following strategy. Reduce Part I (Pick an extinct animal group) to just picking a group and then finding pictures online (such as through Google Images) to familiarize students with the animal groups. Then do Part II and III and skip part IV. If time allows, consider repeating the activity with a second group of animals, preferably one that lived at a very different time interval.