Glossary of Terms

Definitions of paleontological and entomological terms used throughout this site.

Amber
Fossilized tree resin, often preserving insects in three-dimensional detail.
Angiosperm
A flowering plant. Angiosperms diversified rapidly during the Cretaceous and now dominate most terrestrial ecosystems.
Chitin
A tough polysaccharide that forms the exoskeleton of insects and other arthropods.
Coleoptera
The order of beetles, the most species-rich order of insects.
Compression fossil
A fossil formed when an organism is flattened in sedimentary rock, preserving an outline and surface details.
Convergent evolution
The independent evolution of similar features in unrelated lineages, driven by similar selective pressures.
Dicondylic mandibles
Mandibles (jaws) with two points of articulation with the head capsule, a feature of winged insects and their relatives.
Diptera
The order of true flies, characterized by having only one pair of wings (the hindwings are reduced to halteres).
Elytra
Hardened forewings of beetles that protect the membranous hindwings. Singular: elytron.
Eusociality
A social system with reproductive division of labor, cooperative brood care, and overlapping generations. Found in ants, some bees, wasps, and termites.
Exoskeleton
The external skeleton of arthropods, composed primarily of chitin and proteins.
Gymnosperm
A seed plant that does not produce flowers or fruits (conifers, cycads, ginkgoes). Dominated land vegetation before angiosperms.
Hemiptera
The order of true bugs, characterized by piercing-sucking mouthparts. Includes cicadas, aphids, and shield bugs.
Holometaboly
Complete metamorphosis: the developmental pattern with egg, larva, pupa, and adult stages.
Hymenoptera
The order including wasps, bees, and ants.
K-Pg extinction
The mass extinction event ~66 million years ago at the Cretaceous-Paleogene boundary, caused by an asteroid impact.
Lagerstätte
A sedimentary deposit with exceptionally preserved fossils. Plural: Lagerstätten.
Lepidoptera
The order of butterflies and moths.
Ma
Abbreviation for 'mega-annum' (million years ago).
Mandibles
The primary jaw-like mouthparts of insects, used for biting, chewing, or cutting.
Meganisoptera
An extinct order of giant griffinfly insects related to modern dragonflies. Includes Meganeura and Meganeuropsis.
Neoptera
The large group of winged insects that can fold their wings flat over the abdomen. Includes most modern winged insect orders.
Neuroptera
The order of lacewings, antlions, and owlflies.
Ovipositor
The egg-laying structure of female insects.
Palaeodictyoptera
An extinct order of Carboniferous-Permian insects with piercing-sucking mouthparts and often prothoracic winglets.
Palaeoptera
The group of winged insects that cannot fold their wings (dragonflies and mayflies).
Pangaea
The supercontinent that existed during the late Paleozoic and early Mesozoic, containing most of Earth's landmasses.
Parasitoid
An organism that develops on or inside a host, eventually killing it. Parasitoid wasps are a major component of insect diversity.
Pterygota
The subclass of winged insects (and secondarily wingless forms derived from winged ancestors).
Tracheal system
The respiratory system of insects, consisting of a network of tubes (tracheae) that deliver oxygen directly to tissues.