November 2025: Tapir-toothed pig

Listriodon splendens Meyer, 1846

SNSB-BSPG 1929 I 47
Lower jaw
Neogene: Middle Miocene: Upper Freshwater Molasse, 12 million years
Markt Rettenbach (Swabia, Bavaria)

Length 260 mm, width 170 mm

In 1929, the Bavarian State Collection received a donation of fossil mammal remains from the clay pit in Markt Rettenbach, near the city of Memmingen. The collection included numerous parts of a Listriodon splendens skeleton. At the time, these were the most complete remains of this particular pig and caused a palaeontological sensation. As early as 1930, Ernst Stromer von Reichenbach reported on it and illustrated the particularly well-preserved lower jaw bone. Most of the bones were lost during World War II, but, fortunately, this lower jaw bone survived.

Listriodon splendens was a large species of pig that migrated from Asia to Europe in the Middle Miocene, some 14.5 million years ago, and vanished c. 11 million years ago. Unlike other pigs living at the same time, Listriodon splendens already had a long facial skull similar to that of present-day pigs. The incisors were shovel-like and distally widened, and there was pronounced sexual dimorphism in regard to the shape of the canines, with very large upper tusks in the males and significantly smaller ones in the females. While the omnivorous dentition of other pigs is characterized by molars with rounded cusps on the chewing surface, the molars of Listriodon splendens have two transverse ridges each. This meant that this pig was perfectly adapted to a specialized plant-based diet.

Listriodon splendens found ideal living conditions in Europe. Due to gradual global cooling, however, its habitats gradually changed; evergreen closed forests gave way to more open woodlands with wintergreen but frost-sensitive or deciduous trees. Based on detailed analyses of the molars, experts have concluded that Listriodon splendens fed on a wide variety of plant parts from low-growing vegetation, but without rooting around in the ground for food, as today’s pigs do. The sexual dimorphism exhibited by the upper canines also indicates social behavior typical of pigs in more open habitats.

The molars of Listriodon are very similar in shape and function to those of tapirs. However, this similarity is not due to a close phylogenetic relationship, but rather to biological convergence, i.e., the same adaptation due to similar evolutionary selection pressure. It is assumed that Listriodon splendens occupied a similar ecological niche to that of tapirs today. With the further opening up of woodlands and the emergence of extensive grasslands at the beginning of the Late Miocene, food availability changed and Listriodon splendens eventually became extinct.

Gertrud E. Rössner (SNSB-BSPG München)

Fig.: Depiction of a male Listriodon splendens
(Paschalis Dougalis, Munich, fecit).