There are some really huge animals in our world today. While whales and elephants spring immediately to mind, they don’t bite. When thinking of the fearsome and toothy creatures that roam the world, sharks and grizzlies might top the list. However, their bite doesn’t compare to this monster of the past.
The extinct Thylacoleo (pronounced THIGH-lah-co-LEE-oh) carnifex is a genus of Pleistocene Australian marsupial mammals. It is the largest carnivorous Australian mammal and is often referred to as the “meat-cutting marsupial lion.” It had a skull the size of a lion’s head and had large tusks and crushing molars.
Despite weighing over 200 pounds, Thylacoleo carnifex was an adept climber. It had several unique characteristics, including flesh-shearing teeth and a lethal thumb claw. This makes the T. carnifex fascinating for archaeologists, paleontologists, historians, and animal enthusiasts.
Description and Size
Thylacoleo carnifex was discovered during the nineteenth century by Richard Owen. He was also the one who gave it its name. Its discovery debunked beliefs that the large marsupial mammals of Australia, such as the giant wombat, lived prosperously because there were no predators. Based on artist renderings of T. carnifex, this animal was as dangerous—or more—as any of the big cats today.
Experts believe that T. carnifex would have preyed on the Procoptodon, koala, and kangaroo. And while giant wombats would have been spared, marsupial lions would have most likely victimized the young Diprotodon.
Marsupial lions were about five feet (152.4 cm) long and two feet (61 cm) in height. It was as long as a leopard but bigger than the other marsupial animal, Pilbara ningaui. Researchers estimate that the T. carnifex weighed around 286.6 pounds (130 kilograms).
Marsupial lions had a short skull that allowed them to have stronger biting muscles in its jaw.
©Arip Apandi/Shutterstock.com
Tail
The tail of T. carnifex was similar to that of a kangaroo. It was long and powerful and contained narrow bones called chevrons. These were intended to protect the animal’s blood vessels. Marsupial lions used their tails for balance and to stand upright when catching prey.
Hind Legs
Marsupial lions also had great power in their hind legs. However, this does not mean speed, so paleontologists believe that this predator stalked its prey from the treetops, dropping in on them when it was ready to feed. This is similar to how Tasmanian devils and other large cats stalk their prey.
Teeth
These big cats were diprotodontian, which means “two front teeth.” They used the two prominent incisors from their lower jaws that gave these predators the most powerful bite for their size of any known species, living or extinct. Experts originally posited that these mammals fed on plants rather than animals, but modern anatomists said T. carnifex also had strong jaw muscles and sharp premolars.
Front Legs and Forepaws
Marsupial lions had powerful front legs accompanied by sharp claws that could quickly slash the bodies of their prey. Their forepaws had retractable claws for climbing trees and securing prey. The purpose of the claws can be compared to how regular house cats today use theirs.
Brain and Nasal Cavity
CAT scans have revealed that marsupial lions relied heavily on their sense of hearing, sight, and smell. They also had a sizeable and highly developed nasal cavity, resulting in their strong sense of smell. These animals also had structures in the palate, indicating the presence of a specialized organ that could detect pheromones. These compounds help Tasmanian devils and other related species assess female species’ reproductive receptiveness.
What Did Thylacoleo carnifex Eat?
There is much debate about the kind of diet that T. carnifex followed. At first, the species was thought to be an herbivore until Richard Owen described it as a “predatory beast.” Today, T. carnifex is referred to as a carnivore, bone crusher, and scavenger. It is widely believed that they fed on crocodile eggs, carrion, meat, and bone marrow.
While others still believe it could chew plants, paleontologist Robert Broom has pointed out the lack of grinding teeth in T. carnifex. With no grinding teeth, it could not have possibly processed plant matter. If there were any plant matter in its diet, it would have been minimal.
There is evidence to suggest T. carnifex was a carnivore. The teeth were designed to slice through flesh and bones. Plus, it has powerful legs and arms and retractable thumb claws characteristic of predators. The shape of their head is similar to other carnivores’ skulls, except for the reduced canines and premolars.
Research published in 2005 in the journal Proceedings of the Royal Society B: Biological Sciences “calculated theoretical maximum bite forces using the ‘dry skull’ method.” At the top of their list of 49 specimens was the Thylacoleo carnifex. According to their calculations, this creature’s bite force exceeds that of any mammal predator, extant or extinct, and suggests that this species could have taken on much bigger prey than itself, including the giant wombat.
Habitat
T. carnifex lived in the plains of Australia. That’s also where its fossils have been found. The places where these fossils were found has been described as dry, open forest, such as the Darling Downs, Naracoorte and Nullarbor caves, and Wellington. Some experts believe that T. carnifex stayed up in the trees while stalking prey.
Marsupial lions may have also lived inside caves since some fossils were discovered there. Some of these caves have claw marks on the walls, suggesting the presence of a giant predator. In May 2002, speleologists found one complete and a dozen incomplete skeletons of this species in cave openings in a remote part of the Nullarbor Plain.
Before that, this creature was known only for the fragmentary remains of its teeth, postcranial fossils, partial skulls, and partial jaws. An almost-complete skeleton was found in 1966, but it lacked a foot and tail. After this, more skeletons were found in the Naracoorte Caves in South Australia.
This species was distributed across Australia during the Pleistocene era. It was found in Northern Territory, Queensland, Wellington Caves (New South Wales), Western Australia, and Naracoorte Caves in South Australia.
Threats and Predators
It is hard to imagine a threat to T. carnifex since it is considered the largest carnivorous mammal of its time. It was neither purely an apex predator nor a scavenger. Instead, it was a bit of both. Its size didn’t allow it to be skilled at chasing prey. Researchers suggest it could have been a great ambush hunter and most definitely a scavenger.
It wouldn’t take long before prey succumbed to this animal’s powerful legs and jaw. This mammal had incisors in the front of its jaw and a third molar along the cheek that acted as a shearing blade.
Extinction
Humans are the possible reason why T. carnifex became extinct. Hunters most likely hunted the herbivore animals from which this predator fed, leaving the animal without a source of sustenance and ultimately leading to its extinction. Based on some cave paintings, it is also possible that humans hunted T. carnifex.
Similar Animals to Thylacoleo carnifex
Despite its common name, Thylacoleo carnifex is not related to lions. It is a member of the order Diprotodontia (giant wombats). Its closest living relatives are koalas. Its size and weight have been compared to a leopard and cougar, respectively.
- Koalas – An arboreal herbivorous marsupial native to Australia. They have solid and razor-sharp claws that can cause injuries. Like marsupial lions, koalas also have a strong bite. They may appear friendly, but they can also lash out and become aggressive.
- Wombats – These short-legged marsupials are also native to Australia. They are only 40 inches in length and have small, stubby tails. Wombats are only friendly when they are babies. Adult wombats can become aggressive.
