定義： Insect mouthparts that are concealed inside the head by folds of the head capsule. The mandibles and maxillae are located inside the oral chamber, and only the tips of the mouthparts protrude from the oral opening.
定義： The number of fossil occurrences in the Paleobiology Database (https://paleobiodb.org) that are identified as belonging to a particular taxon or any of its subtaxa.
