🪱 Worms: Flatworms, Roundworms & Annelids
Three very different phyla of animals that share a worm-like body plan — but differ dramatically in structure, function, and complexity.
🔑 Key Idea
Not all worms are the same! The three major worm phyla — Platyhelminthes (flatworms), Nematoda (roundworms), and Annelida (segmented worms) — belong to completely separate groups with very different body plans. Flatworms are the simplest, roundworms are slightly more complex, and annelids are the most complex worm-like animals.