History of invertebrate paleozoology and simpler sea-dwelling organisms. By far, invertebrate paleozoology is the easiest type of fossil collecting. "Unlike" the difficult-to-analyze and hard-to-interpret fossils of paleobotany (plants) and micropaleontology (microbes), and "unlike" the rarely found and poorly preserved skeletons of vertebrate paleontology, invertebrate fossils are usually both common and simple to identify. This is because many prehistoric invertebrates were hard-shelled mollusks, brachiopods, trilobites, bryozoans, crinoids or corals who were buried amid marine, sediment-preserving conditions; and therefore frequently fossilized. Stone-age people were without doubt the very first fossil collectors. Fossilized echinoderms have been found in Dunstable, Bedfordshire, central England, decorating a long-buried human skeleton;
Physalia utriculus Physalia utriculus Physalia utriculus, also called blue bottle or Indo-Pacific Portuguese man-of-war, is a marine hydrozoan of the order Siphonophora found in the Indian and Pacific Oceans. A gas-filled bladder allows it to float on the surface, propelled by currents, tides, and by a sail at the top of the bladder. A single long tentacle of venomous cnidocytes, hanging below the float, provides the animal with a means of capturing prey. Like the Atlantic Portuguese man o' war, the Indo-Pacific Portuguese man o' war is not a true jellyfish but a siphonophore, a colonial animal made up of tiny specialised