Metridiochoerus was an extinct genus of African pigs that lived during the Pliocene and Pleistocene. The best-studied species, M. andrewsi, is known from teeth, skulls and parts of the skeleton in eastern and southern Africa. The genus is included in the ice-age animal catalogue, although its history began before the late glaciations that define many popular images of the Ice Age.
Its molars changed through time, and paleontologists use stages of third-molar development to compare fossil localities. Very high crowns in some later populations indicate heavy wear from abrasive foods. Those observations are informative only when the specimen, population and layer are kept distinct.
Quick facts
| Scientific name | Metridiochoerus |
|---|---|
| Group | Mammalia, Artiodactyla, Suidae |
| Age | Pliocene to Pleistocene |
| Range | Eastern and southern Africa |
| Best-studied species | M. andrewsi |
| Known material | Teeth, skulls and parts of the postcranial skeleton |
| Diet | Plant foods; later populations show evidence of grazing |
| Key feature | Large canine tusks and increasingly high-crowned molars |
What can the fossils tell us?
The height and complexity of third molars are useful for comparison. They support biostratigraphic work only when read with the rock layers, not as a stand-alone date.
Very high molar crowns in some later material are consistent with repeated wear from abrasive plant foods. Evidence from Gondolin supports grazing there, not one fixed diet for every species.
Some distal forelimb bones have been compared with warthogs that rest on their wrists while grazing low. The joints permit that interpretation but do not preserve the behaviour itself.
African fossils and changing molars
Metridiochoerus is a suid, the family of pigs. The genus includes several species, but M. andrewsi provides much of the detailed evidence. Its fossils include jaws and teeth as well as portions of the skeleton from eastern and southern Africa.
Across successive populations, the molars became taller and more complex. Paleontologists compare the stages of third-molar eruption and wear when correlating deposits. This biostratigraphic method is useful because dental development changes in an ordered way, but it must be combined with stratigraphy. One large or worn tooth cannot date a layer by itself.
Teeth and a changing plant diet
High-crowned molars resist abrasion. In late material from Gondolin, exceptionally tall crowns are consistent with an animal that processed abrasive plant foods, and the evidence has been interpreted as specialised grazing. That is a population-level result, not a universal menu for every species or locality.
Tooth height describes resistance to wear rather than naming each plant. Sediment, associated fossils and other dental evidence help place the wear in context. A specimen from one African site should not be used to assume identical feeding across the full range and several million years of the genus.
Body size and how estimates vary
Body mass estimates for adults from Gondolin were derived from the ankle joint and other supporting dimensions. One reconstruction gives approximately 380 kilograms for males and 270 kilograms for females, with uncertainty of around 50 kilograms. Those values describe one late population and its estimation method; they are not measurements for every species in Metridiochoerus.
The projecting canine teeth formed tusks. They may have played a part in display or competition, but the bones do not preserve a particular social encounter. A reconstruction should not turn large tusks into proof of a single fighting style.
Walking and feeding low vegetation
Distal bones in the front legs from Gondolin have been compared with the wrist-supported posture used by living warthogs while they graze close to the ground. The joint surfaces make such support plausible. It is a functional interpretation from anatomy, not a preserved trackway showing that every Metridiochoerus fed in that posture.
The genus lived alongside other African suids, including Kolpochoerus in some regions. The two did not have identical tooth histories. Older forms such as Nyanzachoerus help document the diversity of African pigs before and during the wider Pliocene and Pleistocene record. Related hippo fossils are discussed in the profile of Hexaprotodon.
What the record can establish
Teeth provide a useful sequence for comparing localities, and selected molars reveal repeated wear from abrasive foods. Limb bones support a possible wrist-resting posture at low feeding height. Body mass estimates are available for a particular population, with stated uncertainty.
The fossils do not establish one exact mass for the whole genus, a single diet across Africa, or the tusks' precise social function. Keeping locality and species attached to each inference produces a more reliable account than turning several populations into one timeless “giant pig.”
Frequently asked questions
When did Metridiochoerus live?
The genus is known from Pliocene and Pleistocene deposits in Africa.
Was Metridiochoerus larger than a modern warthog?
Some late male M. andrewsi estimates are substantially heavier than a modern warthog, but they come from a particular population and carry a broad margin of error.
What did Metridiochoerus andrewsi eat?
Very high molar crowns in some late populations fit grazing on abrasive plant foods. The evidence does not establish the same diet for every species and locality.
Did it walk on its knees?
Some wrist joints may have supported the front of the animal while it fed low, as in warthogs. This is a functional inference, not a directly observed behaviour.