Life before the dinosaurs was pretty amazing—and very fragile! Discover what Earth was like for Cambrian creatures, from the smallest ocean-dwellers to the first land animals. A video from an extensive biology playlist explores how early...

Dimetrodon lived before flowers, and people often believe it was a dinosaur. Research, however, proves a different story. An informative video teaches more about the dimetrodon, a mammal often confused for a reptile. It explains the...

Dimetrodon is generally featured in children's books about dinosaurs even though it wasn't a reptile and lived in an earlier era than dinosaurs. The way life developed wasn't as smooth as many people think. The video focuses on the...