Toxodon

Description & Size

A Toxodon is an extinct genus of South American mammals. It’s a member of Notoungutata, one of several now extinct orders of hoofed mammals indigenous to South America.

• The Toxodon was 9 feet long and 4 ft 11 in high at the shoulder. 
• The teeth of the Toxodon have no roots, growing forever like those of rodents and lagomorphs.
• Toxodon likely had a long snout. However, this snout wouldn’t have become fossilized. The nasal opening positions are similar to snouted animals, though.
• The vertebrae were extra-supported. Therefore, the head was likely very large and needed extra support. We expect that this creature was very heavy due to the bone structure.
• The body was sloped, as the hind legs were longer than the front legs.

Diet – What Did Toxodon Eat?

Toxodon are thought to have been herbivores, quickly adapting to their situation, depending on what plants were available. They are known to change their eating habits depending on where they are. For instance, they had an almost totally browsing diet in the Amazon rainforest.

They developed mixed feeding in Bahia and the Pampas and almost completely dominate the grazing diet in the Chaco.

Browsing is when plant-eating species will eat high-growing plants such as leaves, soft shoots, and fruits. Grazing is the opposite of browsing, as it consists of such species eating low-growing grass and plants.

Habitat – When and Where It lived

Toxodon had a wide distribution in South America during the late Pleistocene, extending from the Pampas to the Amazon rainforest.

Charles Darwin was one of the first people to record the Toxodon, as he found fossils while on his voyage. Toxodon fossils led Darwin to believe that the animals in Europe were different from those in America. Therefore, they helped prompt his theory of evolution.

During the Pleistocene, it was likely that the Toxodon was extremely common. If you could go back in time, you would find large populations of them during the Great American Interchange.

During this period, the formation of the Isthmus of Panama created a land bridge. This bridge joined North and South America. Of course, this allowed previously isolated animals to mingle. However, not all animals benefited from this period. After all, some prey animals found themselves hunted by new predators.

Threats And Predators

During the time Toxodon was around, there was a spread of North American predators such as the sabre-toothed cat, Smilodon.‭ ‬These cats likely hunted very large animals at the time, as they required a lot of meat. They could not spend their time wasting energy on small animals.

This species of cat likely hunted the Toxodon when it was exposed to it. However, these cats didn’t originally share a range with the Toxodon, so this hunting wouldn’t have occurred until later.

Humans were also a problem for the Toxodon. Scientists have found arrowheads with fossils of Toxodon, which shows that humans did hunt them. It is possible that the threat of humans eventually also caused the Toxodon to go extinct.

In the end, it was likely multiple predator threats that lead the Toxodon to extinction.

However, other theories abound. Most of the theories are linked to the disappearance of other megafauna. Therefore, we don’t really know why the Toxodon went extinct.

Discoveries and Fossils – Where It was Found

Toxodon was found throughout South America. It was quite populous at the time it lived. Fossils of Toxodon have been found in Brazil, Argentina, Bolivia, Paraguay, and Uruguay.

Toxodon seems to have been one of the most common herbivores across South America when it was around. In this way, it was similar to the modern buffalo.

Extinction – When Did It Die Out?

The Toxodon went extinct soon after the last ice age at the beginning of the Holocene period, almost 11,700 years ago. They are part of the Quaternary extinction event, along with almost all of the large animals in South America.

It’s thought that new predators from the land bridge connecting North and South America were the cause of bringing in new predators to the Toxodon. There has also been a theory that humans were a large part of the extinction of this creature, due to there being arrowheads in and around certain fossils.

Some paleontologists disagree and chalk it up to disease, a natural disaster, or some other cause that destroyed all of the megafauna of that time.

Similar Animals to The Toxodon

• Gyrinodon is an extinct genus of Notoungulate, belonging to the family Toxodontidae. It lived during the Late Miocene and the Early Pliocene in what is today South America. This animal was approximately the size of a modern rhinoceros, and they were similar in build and also appearance. Like most of its close relatives, the Gyrinodon’s size was much larger than any other mammal in its habitat.
• Rhynchippus was about 3.3 ft long and weighed up to 226 pounds. Their body was supported by clawed toes. Their teeth are extremely similar to rhinos, but they actually weren’t related to them. Instead, they were related to the Toxodon.
• Proadinotherium is considered to be among the most basal and oldest member of the Toxodontidae. It is thought that it was an herbivorous animal the size of a sheep, with an elongated body and rather short legs. It was probably more slender-built than its relatives. The legs, in particular, had more delicate and slender bones than those related to it.

1. Wikipedia, Available here: https://en.wikipedia.org/wiki/Toxodon
2. Natural History Museum, Available here: https://www.nhm.ac.uk/discover/what-is-toxodon.html
3. National Geographic, Available here: https://www.nationalgeographic.com/science/article/darwins-strangest-beast-finds-place-on-tree