Image of a scientist with a skeleton and replica of a dodo bird.

8 of the strangest extinct species in history

We tend to think of evolution as a straight line. One which leads tiny, single-cellular life forms breeding in volcanic primordial soup, through millions of years of environmental changes and genocidal cataclysm, all the way to us at the end: the upright, vertebrate ape species with the opposable thumbs, capable of bringing nature to heel. This is a typically egocentric view of a process which has been going on for millions of years, and one which will (hopefully) carry on quite unimpeded long after we humans have croaked. But it's one that completely ignores extinct species.

Evolution is a lot more like a sprawling system of roots and branches. Some shoots twist off in one direction, and grow taller and taller, while others are trimmed and cut down. There’s only so much space and resources on our blue planet for a finite number of creatures, and competition is fierce. Over the countless millennia, the vast majority of all life has gone extinct, and as you can see below, in Earth’s long history, nature has thrown up some pretty weird-looking creatures, none of which have survived to the present day. Check out some of the oddest extinct species below.

1. Glyptodon

Glyptodon is quite hard to describe. Imagine a huge, armored armadillo, roughly the same size and weight as a Volkswagen Beetle, and you’re on the right track. The Glyptodon lived during the Pleistocene epoch which superficially resembled a turtle, and the ankylosaur dinosaur which lived many years before it. In this regard, the Glyptodon provides scientists with a prime example of convergent evolution within unrelated lineages. Evidence suggests that the Glyptodon was hunted into a state of extinction by human beings, who would have used the hollowed-out shell as a crude form of shelter.

An artist's depiction of a Glyptodon being hunted by humans. Credit: Getty

2. Arthropleura

Arthropleura was a type of giant millipede arthropod which lived on the landmass which is now northeastern North America and Scotland 300 million years ago, in the late Carboniferous Period. These creepy-crawlies are the largest known land invertebrates ever discovered. Because they look like something from King Kong’s Skull Island, they had few, if any, predators, growing up to two meters long and nearly 50 centimetres thick. Arthropleura was able to grow larger than modern species of living arthropods due to the greater pressure of oxygen in Earth's atmosphere in the Carboniferous Period. It was thought to have died out when the climate became gradually less moist, and the marshland succumbed to desertification.

An artist's depiction of an Arthropleura. Credit: Getty

3. Quagga

The quagga is an extinct subspecies of zebra, which lived South Africa before becoming extinct in the 19th century, and was considered to be related to Burchell's zebra; it was approximately 250cm long and around 130cm tall. What distinguished this subspecies of zebra from typical zebras was the pattern of white and brown stripes on its pelt. While alive, Quaggas were said to be wild and lively animals, but not as aggressive or energetic as Burchell's zebra. Quaggas were sadly hunted to extinction by Dutch settlers and later by Afrikaners in the 1800s. Currently there is a breeding program in South Africa that is aiming to recreate the distinctive stripe pattern through husbandry.

Two zebra from the South African Quagga breeding program. Credit: Getty

4. Meganeura

Meganeura is a type of insect from the Carboniferous period, which looks a lot like a gigantic version of a contemporary dragonfly. It was so gigantic that its wingspan was around 65cm! Meganeura were predatory animals, and caught and ate other insects. The first Meganeura fossil was first discovered in the French Stephanian Coal Measures back in 1880. It is believed that they died out due to changes in the earth’s atmospheric pressure, which prevented them from maintaining their large size.

An illustration of the Meganeura species. Credit: Getty

5. Purassaurus

The purussaurus is like a yacht-sized crocodile, which inhabited the continent of South America during the period geologists refer to as the Miocene epoch. Paleontologists estimate that these massive amphibious lizards would have grown to be around 10 metres in length, and weighed approximately five metric tonnes. Zoologists have since proposed that, although their large size gave them many advantages in their native territory, it also made them vulnerable to environmental changes which favoured smaller species.

A scale model of the Purassaurus species of amphibious lizard. Credit: Getty

6. Megalodon

Megalodon, (which means "big tooth" from Ancient Greek), is an absolutely colossal extinct species of shark, which lived around 24 million years ago, during the Early Miocene era to the end of the Pliocene era. This gigantic, razor-toothed monster is commonly regarded as one of the largest and most powerful predators in vertebrate history. Forget Jaws, or any other shark movie you care to mention. Megalodon fossils suggest that terrifying leviathan reached a length of nearly 20 meters. Its jawbone is so wide and high that marine biologists have good reason to believe that it could comfortably swallow a human being whole. But although it appears to be the apex predator of all apex predator, it eventually died out as a result of perfectly mundane circumstances. Megalodon apparently preferred warmer waters, and the onset of the ice ages inevitably led to extinction.

A woman standing within the jaws of a Megalodon, with arms spread, to show how wide its bite was. Credit: Getty

7. Anomalocaris

Now, this is one of the strangest sea creatures I’ve ever seen, period. It’s like an unholy hybrid of shrimp, shark and seahorse. Anomalocaris propelled swam by undulating flexible lobes which acted as fins. Anomalocaris boasted a large head and a pair of eyes on stalks, much like a slug or snail, as well as a disk-like mouth composed of 32 separate overlapping plates. When Anomalocaris managed to catch prey, its disk-like mouth would constrict to crush prey, before tooth-like prongs pushed it down the beast’s throat. Two large 'arms' with barb-like spikes were in front of the mouth. Paleontologists are still uncertain as to why Anomalocaris became extinct.

An artist's illustration of anomalocaris canadensis. Credit: Getty

8. Great Auk

Think that all penguins are cute and cuddly? Think again. The Great Auk is a species of bird which resembled a gigantic penguin, which was almost as tall as human beings, but became extinct sometime during the mid-nineteenth century. Despite their outward appearance, the Auk was actually biologically unrelated to the birds we call penguins. As a matter of fact, penguins were actually discovered sometime later, and were named thus by sailors due to their resemblance to the great auk. They thrived on rocky, isolated islands in the North Atlantic, and had a similar diet to other aquatic birds, which included capelin, and crustacean. The Great Auk would mate for life, and both parents participated in the incubation of their single egg. The last surviving specimens were killed on Eldey on 3 June, 1844, after being hunted to extinction by humans.

Taxidermy of a Great Auk Credit: Getty

Sadly, the human race has been responsible for the extinction of a great many irreplaceable animal thanks to our deforestation, exploitation of natural resources, and callous disregard for the environment. Which is all the more reason why World Animal Day should be so important to us all this year.