GLOSSARY OF AVIAN EXTERNAL ANATOMY Prepared by Dennis Paulson This list of mostly technical terms is provided as a service to those not familiar with them. Many of them are in general use in anatomy, others restricted to birds. If any obvious ones are missing, I would appreciate a note to that effect. acuminate - abruptly narrowing to sharp point acute - sharply pointed alula - a small winglike group of feathers at the bend of the wing, supported by the anteriormost digit angulated - with an angle anisodactyl - three toes in front and one behind, as in perching birds anteriad - toward the front apteria - plural of apterium apterium - unfeathered area between feather tracts auditory meatus - ear opening beak - the bill bipedal - standing on two rather than four legs booted - not divided into scales (tarsus) caeca - plural of caecum caecum - a diverticulum on each side of the gut at junction of small and large intestines, for additional digestion caudad - tailward (toward the rear) cere - fleshy area at bill base enclosing nostrils cloaca - common chamber at end of digestive and urogenital systems commissure - line formed by meeting of maxilla and mandible compressed - flattened from side to side cornified - with a keratinous (horny) covering coverts - smaller feathers covering large wing and tail feathers culmen - upper ridge of maxilla decurved - curved downward toward tip depressed - flattened from top to bottom elevated - above front toes (hallux) emarginate - notched (tail) filamentous - very long and slender filoplumes - hairlike feathers gonys - lower edge of mandible graduated - feathers successively shorter from center to outside (tail) gular sac - bare skin on throat and base of mandible hallux - hind toe imperforate - separated by a septum (nostrils) incumbent - at level of other toes (hallux) lamellate - coarse or fine parallel ridges or plates (at cutting edge of bill) lobate - with lobes (toes) lore - area between eye and bill mandible - lower bill maxilla - upper bill nares (sing., naris) - nostrils nictitating membrane - "third eyelid" drawn over the eye to clean it notched - with a notch, like a pointed bite taken out of it (bill, tail) obtuse - not very sharply pointed operculum - fleshy partial covering over nostril palmate - completely webbed (3 toes connected) pamprodactyl - all four toes in front, as in swifts pectinate - comblike (structure on one side of central toenail) perforate - continuous with other side (nostrils) posteriad - toward the rear primaries - 9-10 or more outermost flight feathers, attached to hand pteryla - feather tract pterylae - plural of pteryla raptorial - feet with long, strong toes and long, sharp, curved claws rectrices - plural of rectrix rectrix - tail feather recurved - curved upward toward tip remex - large flight feather remiges - plural of remex reticulate - with small netlike scales (tarsus) rhamphotheca - horny covering of bill rictal - referring to the corners of the mouth scutellate - with large transversely oriented scales (tarsus) secondaries - flight feathers attached to forearm (ulna) semipalmate - webbed only at base (toes) serrate - with teeth like saw (cutting edge of bill) spatulate - spoon-shaped (bill) sternum - the large bone underlying the breast syndactyl - two front toes partially joined, as in kingfishers tarsi - plural of tarsus tarsometatarsus - the bone underlying the tarsus tarsus - lowest segment of leg, before toes terete - round in cross section tertials - flight feathers attached to upper arm (humerus) tibia - segment of leg that protrudes from feathers, above "ankle" tomium - cutting edge of both maxilla and mandible totipalmate - all 4 toes connected by web uropygial gland - papilla on top of uropygium that secretes oils for preening uropygium - the fleshy posterior end supporting the tail vent - opening of cloaca zygodactyl - two toes in front and two behind, as in woodpeckers This information is provided by the Slater Museum of Natural History University of Puget Sound Contact: dpaulson@ups.edu Last Updated: November 11, 1996 Copyright (C) 1996, University of Puget Sound. All rights reserved.