Ecology, Conservation and Management of Wild Pigs and Peccaries

Part I: Evolution, Taxonomy, and Domestication

30

The extant species of Potamochoerus are typical omnivorous

suids. The premolars and incisors are well developed. The third

molars are anteroposteriorly short, low-crowned, and display

few main cusps with thick enamel and bunodont morphology

(Harris & White 1979). The insertions for the temporal mus-

cle are well marked on the cranium. The insertions of the ros-

tral muscles controlling the movements of the rhinarium when

digging for underground foods are also well marked. Those

characteristics are also found in extant species of the mostly

Eurasian genus Sus.

The two other genera of extant African suids (Hylochoerus,

Phacochoerus) display much more specialized morphologies

related to their herbivorous diets. Their premolars are reduced

both in terms of number and size. The incisors are also reduced or

even absent. The third molars are anteroposteriorly more elon-

gated, higher crowned, and display numerous main cusps with

thinner enamel (Souron 2012). The insertions for the temporal

and rostral muscles are reduced, whereas the insertions for the

pterygoid and masseter muscles (involved in the lateral compo-

nent of the mastication) are strongly marked. All those morpho-

logical characteristics are presumably related to the functional

needs to reduce tough plant matter to small fragments.

In Hylochoerus, the molars are characterized by well-separated

and anteroposteriorly compressed cusps, giving a bunolopho-

dont occlusal surface (Souron et al. 2015b). The cusps are encom-

passed within a thick cover of cement. The third molars are

Figure 3.1 Changes in third molar morphology and stable carbon isotopes in Nyanzachoerus and Notochoerus. Right panel: chronological ranges for each species

(grey bars). First and last occurrences follow White (1995), Boisserie et al. (2014), and personal observations. Abbreviations: syr, Ny. syrticus; tul, Ny. tulotos/Ny. devauxi; khi,

Ny. khinzir; dev, Ny. devauxi; way, Ny. waylandi; aus, Ny. australis; kan, Ny. kanamensis; jae, Ny. jaegeri; eui, No. euilus; cap, No. capensis; sco, No. scotti; cla, No. clarki. A selec-

tion of upper third molars in occlusal and lateral views illustrate the morphological changes and the omnivorous versus herbivorous morphotypes. Left panel:

stable carbon isotopes of enamel of Nyanzachoerus and Notochoerus (personal compilation of literature, full list of references available on request).

.005

12:31:27

http://www.ebook3000.com