Invertebrate paleontology includes the study of such diverse organisms as trilobites, ammonites, crinoids (sea lilies), mollusks and insects, as well as microorganisms such as foraminiferans. The VMNH invertebrate paleontology collections include one of the most extensive collections of Tertiary invertebrates, mostly from the Mid-Atlantic Coastal Plain. There is also a world-class collection of Triassic insects from Virginia.