The black woollycoat has a thick coat of cottony wool, which keeps it warm in the winter. The wool is especially thick around its sides, giving the impression of wings. Whenever there is chilly weather, a black woollycoat's babies nestle in their mother's wool-wings. However, since the babies are born in summer, this rarely happens.
The thick coat can reach 4.5 centimeters in thickness, making it well-adapted for cold weather. However, this comes at a cost, for when summer arrives, it is unable to quickly shed its coat. To prevent overheating, it fills its large tongue with blood. The hot blood going to the tongue is cooled by the surrounding air, thus cooling the body when it flows back.
The black woollycoat's tongue is very long and thick, even when not filled with blood. The tongue's length, as well as the lengthened neck, increase its range when dabbling for food. The tongue is so long, it makes a loop in the skull, (C) using the crest as storage space. The tongue begins on the left side of
the mouth, and emerges on the right. The channel containing the tongue even passes next to the cranial vault, where the brain sits.
A.: Black woollycoat skull. B.: Black Woollycoat skull, showing brain area and outline of the tongue loop. C.: The tongue loop and oral cavity. D.: Mandible, seen obliquely from the side. E.: Mandible, seen from above; note the narrowness and thinness.
The black woollycoat's tusks are laterally (side-to-side) flattened, and thinner than those of its ancestor. This provides more space for the tongue, for the tongue is far more important in feeding than the tusks.
Black woollycoats cannot chew nor slice their food. Thus, all their food must be swallowed whole.
The large tongue can cause disorders. One disorder results when a young black woollycoat, which has a smaller tongue, develops the habit of stowing its tongue in the wrong passageway. This prevents it from feeding effectively. Depending on the tongue's length, it can be difficult or even impossible to adjust the tongue's position to the correct one. It is hypothesized that this disorder still exists in the population because a tongue stored "incorrectly" provides more room in the floor of the mouth for birth, with the newborn(s) merely brushing against the tongue on the way out. (like most plents, black woollycoats give birth through the mouth.)