Dimetrodons were one of my favorite dinosaurs when I was a kid, even if I didn’t know that they weren’t actually dinos. As a group, they are considered synapsids like us, making modern mammals like us their very distant descendants, by 280-265 million years.
These guys are likely to be in the news in the next several days due to a find in Texas the by Houston Museum of Natural Science of a nearly complete articulated skeleton of Dimetrodon giganhomogenes.
Crikey, but he’s a pretty fellow! (artist’s conception, credit DiBgd)
Keep in mind that complete skeletons are themselves rare, but being able to observe articulation is especially neat, as we can actually see how the joints fit against each other.
You can see just how excited Dr. Bakker is at this discovery in this video. What a great addition to the collection at HMNS.
Ideas for lessons?
Elementary school: Lots of kids will know what a Dimetrodon is immediately, but many won’t know that they weren’t dinosaurs. You can talk about why these aren’t quite dinosaurs. Synapsids have a hole in their skull just behind their eye socket that a jaw muscle goes through. You can ask your students if they knew that they had the same feature. Synapsids also have teeth with different shapes, while reptiles including dinosaurs typically have teeth that are fairly similar throughout. Again, your students have this feature, too, with incisors, molars and canine teeth. Finally, synapsids have legs that are perpendicular to their bodies, like crocodiles, while dinosaurs have legs that are in line with their bodies. We don’t share all of the features of Dimetrodon, but these details can further interest children in learning about science. There are other differences, but this should be enough to get you started on a very fun lesson.
You can pick up a plastic model of one of these anywhere plastic dinos are sold, so a visual aid won’t set you back too badly.
Another exercise would be to ask the students to draw what they think scientists look like. Dr. Bakker is an example of a working scientist that isn’t wearing a lab coat, doesn’t have white hair going in every direction, etc. Make sure that you include some other scientists, and don’t leave out women scientists!
High school: This makes for a good science in the news moment, and again, a plastic toy makes a good visual aid. This also fits into lessons on the history of the earth as an example of life in the Permian period, and if you are in an area of the country that encourages teaching evolution as part of the science standards, these are early ancestors to mammals, even though they are very reptile like.
College: I often start class with an organism of the day, and even though it takes a few minutes out of every lecture, it helps students understand that science is an ongoing process and that we are learning more about life every day.
Furthermore, this can be an examination of cladistics and common ancestry. Review the wikipedia page here, and you can take your class beyond your textbook to examine these topics. Pictures of Dimetrodon and human skulls would be useful in comparing cranial features.
Have fun, and teach on.