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Mouths in adult or larval animals. Frontal views of sea anemone Anthopleura elegantissima, earth worm Lumbricus terrestris, sea urchin Strongylocentrotus purpuratus, grasshopper Anacridium aegyptium, lamprey Petromyzon marinus, tadpole of frog Xenopus laevis, falcon Falco cherrug, and human Homo sapiens. Red dotted line denotes the border of the oral cavity. Md, mandible; Mx, maxilla; P, pharynx; T, teeth; Tg, tongue.
