The Sea Squirts, from Phylum Urochordata (Tunicata)

Another fun pencil and marker sketch of a delicate and lovely group of marine creatures, the sea squirts. Purportedly a “recent” ancestor of the vertebrates (including us), these organisms more closely resemble the sponges (Phylum Porifera) and the Cnidarians (jellyfish, hydra). For a helpful discussion on how scientists attempt to categorize this group, check out this article. It details the major conflict between classifying creatures based on their morphology (shape, body systems) vs. molecular analysis.