Elephants are some of the most iconic animals on Earth. They are the largest of all terrestrial mammals and have been a facet of human culture for thousands of years. Even their prehistoric relatives, the mammoths and mastodons, are well-known to the general public. To most people, the differences between mammoths and mastodons are trivial. What’s one prehistoric elephant to another, right? Wrong! Despite looking similar and coexisting in some parts of the world, mammoths and mastodons are two very different animals.
Elephants, mammoths and mastodons all belong to a group of animals known as Proboscideans. The word “proboscidean” is derived from the word “proboscis” and is a reference to what is perhaps the most distinguishing feature of the group, the trunk. This muscular organ is a fusion of nose and upper lip and serves many functions. Proboscideans are also distinguished form other animals by their prominent tusks, which are larger and more pronounced in the males. Unlike the tusks of most animals, proboscidean tusks are derived from incisor teeth rather than canines. Members of this group rank among the largest land mammals to ever exist including the very largest, the Asian straight-tusked elephant, Palaeoloxodon namadicus. While only three species are alive today, there have been a wide variety of proboscideans over the course of geologic time. Some of them had tusks that pointed downwards out of the chin, others had flattened tusks that resembled shovels and elongated lower jaws, some had tusks in the lower and well as the upper jaw. One type, Stegodon, even had tusks so close together it had to hold its trunk off to the side!
Mammoths are perhaps the most recognizable prehistoric animal after the dinosaurs. Most people are familiar with the woolly mammoth, Mammuthus primigenius, but this is only a single species. Of all proboscideans, the mammoths are the most closely related to modern elephants and first evolved about 5 million years ago. Some species stood over 13 feet at the shoulder and could weigh 10 tons or more. The had long legs to help them efficiently traverse the open grasslands and plains they preferred. Like modern elephants, mammoths were herbivores with enormous, grinding molars designed for coping with a grass-heavy grazing diet. Their domed foreheads supported immense chewing muscles needed to process tough, abrasive foods. Only one tooth was exposed in each part of the jaw at a time and as it wore down, it would be replaced by the tooth immediately behind it. Mammoth tusks were much longer than those of their living cousins, measuring up to 14 feet and weighing over 200 pounds each and had tips that tended to curl inwards. This would have allowed males to engage in violent shoving matches during the breeding season, and there is even one fossil of two bulls with their tusks locked together.
Mastodons were only distantly related to modern elephants and first appeared in the fossil record about 30 million years ago. Compared to mammoths and elephants, they have shorter legs, a longer torso, and a lower skull. However, due to their robust build they could weigh just as much as mammoth despite being several feet shorter. Such a big, bulky body was well-designed for pushing through thick vegetation, as mastodons were generally found in more heavily forested habitats than mammoths. Instead of consisting of enameled ridges cemented together, mastodon molars were low and had prominent cusps; the name “mastodon” means “breast-tooth” in reference to the nipplelike shape of these cusps. This indicates they were primarily browsers feeding on leaves and branches. Mastodons had two molars exposed at a time and as a result, wore down their teeth at a greater rate and had slightly shorter lifespans than mammoths or elephants (closer to 40 years rather than 60 or more). Their tusks were curved with forward-facing points and fossil evidence suggests that males used their tusks to gore each other in territorial fights, sometimes fatally.