University of California
Ucmp: Monotremes, Egg Laying Mammals
University of California Berkeley offers a short, concise description about egg-laying mammals with links to more in-depth information.
University of California
Ucmp: Introduction to Trilobita
One of the most famous fossil organisms, trilobites were once a complex group. Learn to tell them apart in this illustrated article that tells how they lived, their body structure, there place in evolution, and the like.