Chapter 1: Evolutionary relationships and taxonomy of Suidae and Tayassuidae7
hair is extremely sparse, so that it appears naked, and the tail tuft
is small and sparse.
The Museum Zoologici Bogoriense (Cibinong, Indonesia)
holds a dozen babirusa skulls confiscated from poachers in
Central Sulawesi, although with no more exact localities. Both
B. babyrussa and B. celebensis are represented, with no inter-
mediate specimens; evidently both species occur within the
boundaries of the province Sulawesi Tengah, but their respec-
tive distributions there are unknown.
It is possible that the Togean babirusa was introduced to
Malenge. It appears intermediate between the other two species,
and it may be that they were both introduced there and have
interbred to form a stable hybrid population. It could also be
that it is a surviving primitive species.
Phacochoerus F. Cuvier, 1817
The warthog. Large-headed, sparsely haired but with a promi-
nent dorsal crest and a white fringe on the side of the face, and
with three pairs of elongated facial warts. Canines are long in
both sexes and emerge from elongated, laterally flaring alveoli;
the tips of the maxillary canines do not occlude with the man-
dibular canines, so they remain sharp throughout life. The brain-
case is shortened and high; the orbits are placed well back and
high up; the ascending ramus of the mandible is very elongated.
There is a pair of deep sphenoidal pits behind the internal nares.
The upper incisors are variably reduced; premolars reduced to 2.
The cheekteeth are high-crowned (hypsodont), with numerous
subsidiary enamel pillars.
Warthog are still common over most of the bush, savanna,
and desert country of sub-Saharan Africa. There are (at least)
two species, as follows.
Phacochoerus africanus (Gmelin, 1788). Common wart-
hog. From the Eastern Cape (South Africa) north to the Berbera
district (Somalia), then west to Senegal, mainly in bush and
savanna country. Long, narrow skull, although with robust,
inflated anterior portions of zygomata. A pair of upper incisors
(sometimes lost with age), three pairs of lower incisors. Third
molars develop roots at the time of eruption. Facial warts are
conical; ears simple leaf-shaped; head ‘diabolo shaped’.
Phacochoerus aethiopicus (Pallas, 1767). Desert warthog
(Figure 1.3). This seems to have existed, in historic times, in two
widely separated populations, one (now extinct) in the Karroo
of South Africa, and one (still extant) in the Horn of Africa –
Somalia, the Ogaden of Ethiopia, and northeastern Kenya from
the Lamu district and the Northern Guaso Nyiro. The skull is
shorter and broader with enormously pneumatized anterior
zygomata and greatly expanded sphenoidal pits. Upper inci-
sors are absent at all ages, and lower incisors rudimentary or
absent. Third molars do not develop roots until the crown is well
in wear. The cheek warts are hook-shaped; ear tips are bent back-
ward; head ‘egg-shaped’.
There seems to be some geographic variation in both species,
but, despite the naming of several subspecies, this variation has
not been properly described. If the two widely separated popula-
tions of P. aethiopicus should prove specifically distinct, the name
aethiopicus represents the southern one, and the northern one
would take the name Phacochoerus delamerei Lönnberg, 1909.
The external appearance of the extinct southern desert warthog
has not been recorded; the description above is based on the still-
extant northern population.Hylochoerus Thomas, 1904
Large, big-headed pigs with black, bristly pelage, exceptionally
broad nasal disk, and enormous, fungus-like suborbital warts
in males (Figure 1.4). Skull with robust, strongly pneumatized
anterior zygomata, especially in males. Skull high-crowned,
braincase strongly angled to the face. Temporal ridges strongly
developed, overhanging the side walls of the braincase. Nasals
curved down in front, with the pre-nasal ossification (which is
separate in other suids) fused to them and to the premaxilla. It
has the flaring tusks and typical occlusal arrangement of most of
the Suidae, with, however, no canine apophyses. Incisors reduced
to a single pair in maxilla; premolars reduced to two in maxilla,
one in mandible. Cheekteeth strongly hypsodont, with much
cement on crown. Forest hog are still tolerably common through
the African forest zone, from Liberia east (but only north of the
Congo River) to Kenya. There are probably three species (Groves
& Grubb 2011; Meijaard & Groves in preparation), as follows.
Hylochoerus meinertzhageni Thomas, 1904. From the
mountains on both sides of the Western (Albertine) Rift Valley,
east to Uganda and the Kenya Highlands and Ethiopia (possibly
extinct in the Republic of South Sudan). Readily distinguished
by its enormous size (skull length of males 407–461 mm, of
females 375–427 mm), very widely flaring tusks, and enamel pil-
lars on the cheekteeth widely separated, with much cement onFigure 1.3 Desert warthog (Phacocoherus aethiopicus) from Tsavo West,
Kenya. Photo by Yvonne A. de Jong and Thomas M. Butynski, wildsolutions.nl.12:28:36