Coryphodon was a medium-large herbivorous mammal, similar to a big tapir, lived in the swamps and along the rivers of the whole North America and Europe 59-51 million years ago, when climate was much warmer and wetter than today, even in Northern Canada, far beyond the Arctic Circle. Maybe it was a semi-aquatic animal, like the modern hippopotamus and tapir.It belonged to the Pantodonta, the first group of large herbivorous mammals appeared on the Earth, after dinosaurs’ extinction. Its genus was described and named by the English palaeontologist Sir Richard Owen (1804-92) in 1845 and includes 6 species today.

C. eocaenus

C. dabuensis

C. lobatus

C. oweni

C. proterus

C. ryani

a) Physical description

- Its body was squat and rounded like that of a hippopotamus, with a broad and rounded head. It was up to 2.3 m (7.7 ft) long, 1 m (3.3 ft) high at the shoulder and it weighted about 500 Kg (1100 lb). Legs were short, strong and hoofed and this animal is considered a slow runner.

- Its jaws had two canine tusks protruding outside the mouth from the upper jaw. These tusks were useful for self-defence, in the strength competitions among males for mating and to pull out roots and tubers from the ground. In total, this mammal had 44 teeth and, most likely, males had longer tusks than females.

- In such a large and massive body, the brain was particularly small, about 90 g, one of the smallest respect to the whole body mass among mammals. Hence, it’s very hard to consider Coryphodon an intelligent animal, but it was in any case able to thrive for 8 million years, maybe helped by the scarcity of large and dangerous predators few millions of years after dinosaurs’ extinction.

- The ears were rounded and rather small, according to the current reconstructions of its body.

- The tail was short and thin.

b) Food

Coryphodon’s vegetarian diet included tubers, roots, leaves and several aquatic plants. North of the Polar Circle, the polar ice cap we know today still didn’t exist in that period and there was a wide temperate or boreal forest and abundant vegetation. Summers were mild and winters wet and not very cold, despite these regions were immersed in the darkness for some months and solar light was present for 24 hours in summer.

Hence, vegetable food availability was variable during the year, but Coryphodon could eat flowers and green leaves (either terrestrial and aquatic) in summer and dead leaves, mushrooms and pine needles in winter. This so flexible diet was one of Coryphodon’ best resources to survive and didn‘t oblige it to migrate southward during winter, as caribou does today.

c) Scientific classification

Class : ................... Mammalia

Order : ................... Cimolesta

Suborder : ............ Pantodonta

Family : ................. Coryphodontidae

Genus : ................. Coryphodon