Trunks, Tusks, and Horns – The Strange Faces of Prehistoric Mammals
Like dinosaurs before them, ancient mammals possessed a wide variety of unique features that made them look quite strange. Let’s dig deeper and look at why some of these funny-looking horns, tusks, and trunks may have existed.
Horns and Knobs
Some prehistoric mammals resembled animals that are still around today, only with more fur to help them survive in their frigid Ice Age habitats. The woolly rhino (Coelodonta) is one such animal. Like the modern white and black rhinoceros, Coelodonta possessed two large horns on its face. Unlike the conical horns of today’s rhinos, Coelodonta’s nose horns were thinner and blade-like, and featured a banded pattern along their length.
Coelodonta probably used its horn like modern rhinos: to protect itself and its young from predators, and to fight amongst each other over a potential mate. Rhino horns are made of keratin, which is the same substance that our hair and fingernails are made of. This makes them different from cows’ horns, which are composed of bone with a keratin covering, and deer antlers, which are completely made of bone.
Another kind of horn found on prehistoric mammals are the blunt, Y-shaped horns seen on brontotheres, such as Megacerops. Though these large mammals resembled rhinos, they were more closely related to horses. Their horns were made of bone, not keratin. Males had larger horns than females, which leads scientists to believe that they were used in combat, with males fighting each other to win the favor of females. Skeletons found with healed rib fractures would suggest that they battled each other by swinging their horns into their opponents’ sides.
Another prehistoric mammal, the Uintatherium, had a completely different kind of head adornment: six bony knobs, called “ossicones” jutted from its skull. These ossicones are not horns, but rather are similar to the bumpy protrusions found on the heads of modern giraffes and okapis. These protruding knobs may have been used for display, defense, or both. In addition to ossicones, also possessed another unique feature: long, curved teeth in its upper jaw, similar to those of saber-toothed cats like Smilodon. It may have used these teeth to protect and defend itself and its young from predators.
Tusks and Teeth
Uintatherium’s unusual teeth bring us to another feature found in some prehistoric mammals: tusks. Tusks are really just enlarged teeth that continue to grow throughout an animal’s life. Today, tusks are found on animals like the walrus, the narwhal, and the elephant. In the past, the relatives of elephants also sported tusks. These include the woolly mammoth, the American mastodon, and an unusual creature called Amebelodon.
The tusks of mammoths and mastodons were similar to those of modern elephants, and probably used for the same purposes. These long, curved tusks were likely used to help dig for water and roots, and clear away obstacles like trees. They could also have been used, like the horns we previously discussed, during battle between two males.
The tusks of Amebelodon were quite different. In addition to the short, downward curving tusks in its upper jaw, this elephant relative also had two flattened tusks in its lower jaw that formed a shovel-like structure. They may have used these tusks to dig up plants to eat, or to scrape bark from trees.
Trunks
In addition to tusks, the prehistoric relatives of elephants also shared another feature with their modern counterparts: a long, flexible nose known as a trunk. In some cases, specimens of prehistoric mammoths are preserved well enough that scientists can get an idea of what their trunks looked like. However, since trunks do not include bones, sometimes scientists must make a best guess at what the trunk of some animals may have looked like in life.
The trunk, also called a “proboscis”, was used for many things. In addition to breathing and smelling (it is a nose after all), the trunk was also used for grasping and touching. Modern day elephants are quite skilled at using their trunks, even for delicate tasks, much in the same way humans use their arms and hands. It’s likely that many prehistoric elephant relatives did the same.
But elephant relatives weren’t the only prehistoric animals believed to have trunks. An unusual prehistoric beast known as Macrauchenia, looked like a long-necked llama, but was probably more closely related to horses and rhinos. On its skull, the nostril openings are on the top of its head, which has led scientists to theorize that it probably had a short trunk, like a modern-day tapir or saiga antelope.
These are just some of the unique structures found on the faces of prehistoric animals. It can be tricky to figure out why some of these facial features exist, but by analyzing bones and fossils and comparing ancient features with those of modern animals, scientists can develop a pretty good idea what some of them might have been used for.