5 Miss Piggy
As the earliest mammals - the insectivores - were specialists, it follows that the omnivore lifestyle must have arisen at some later stage in a group or groups of non-omnivores. In fact, both seed eating and leaf eating arose before omnivory. Twenty million years ago, Dinohyus was undoubtedly a 'specialist' omnivore.
Activity 4
Reread LoM pp. 167-168 and note down the features that have convinced palaeontologists that Dinohyus was an omnivore.
Answer
As usual, the animal's teeth provide the most significant clues. As DA writes 'it had a set of generalised all-purpose teeth that could tackle most foods'. Its incisors did not especially equip it for the grazer's habit of nipping off grass and neither did it have the sort of canines that would be expected in a carnivore. Moreover, Dinohyus had a long snout and disproportionately large olfactory lobes in its brain, features which suggest that it had an acute sense of smell. It seems likely, therefore, that Dinohyus was a genuine omnivore and an early member of the pig family.
So the clinching evidence that Dinohyus was an omnivore comes from its dentition plus the indications that the animal had some kind of face decorations - modestly reflected in the computer reconstruction in the TV programme (05.37). Its presumed good sense of smell is also a tell-tale sign, and is all the more compelling evidence if you review the importance of this sense in relation to eating habits in present-day members of the pig family.
Activity 5
Watch the TV programme from 04.44-12.47 and reread LoM pp. 168-170, making notes relevant to the following topic. Describe in up to 200 words the various sorts of food consumed by different living members of the pig family and the extent to which a good sense of smell plays a role in locating any of these foods.
Answer
The babirusa uses its sense of smell to locate fruits of the Pangi trees (TV programme, 08.12 ). (The male's tusks are certainly the most bizarre upper canines you will encounter in the 'Studying mammals' units. However, they are not linked with feeding - they comprise a sexual display, important in the male-to-male fights that you saw briefly in the TV programme.) The European wild boar eats acorns, beech mast, chestnuts, ferns, earthworms, snails, frogs, lizards, mice and carrion. It also uses its sense of smell to locate truffles, an ancestral habit made use of by humans when they train domestic pigs for this purpose. Peccaries eat cacti. The bush pig ploughs up the ground in its search for roots, corms and bulbs. The giant forest hog eats mainly grass. The red river hog eats mainly fallen fruits. The warthog eats roots and tubers, the leaf bases of grasses and tree bark. The precise ways in which these animals use smell to locate food is unknown, but in the 'wild pig and boar' family as a whole, this sense may well be as important as vision - perhaps more so; the eyes of such animals are generally small.
On this basis, there can be no doubt that members of the pig family are omnivores extraordinaire.