12 Types Of Extinct Human Species And How They Differ

Today, Homo sapiens are the only type of humans on Earth. However, we modern humans are just the most recent of many other human species that once existed. In fact, we don't know how many species, since scientists keep on finding new species of human. As Britannica explains, the forerunners to humans diverged from apes during the Middle Miocene Epoch from 16 to 11.6 million years ago. These nearly-human species then evolved so that by the Pliocene Epoch some 5.3 to 2.6 million years ago, the human genus, Homo, arose.

Species of human are considered distinct by several traits. They are bipedal striders. They generally have large brains. Some also developed tools and use language. These traits became more pronounced as humans evolved further.

What is truly mind blowing is that there were times when there were several different species of human cohabitating the planet. When considering how well we humans of the same species get along with each other, it is not hard to speculate on how intra-human species relations were.

Let's take a look at some of these species of extinct humans and how they differed with one another. The truth of the matter is that the human species was once very diverse.

About 2.5 million years ago, the global climate began to cool. "Origin of the Genus Homo," asserts that this may have been the spark that caused an Australopithecus species to evolve into the first human species. The earliest known of these is Homo habilis, which lived from approximately 2.3 to 1.4 million years ago in East and South Africa. Unlike the preceding australopithecus species, Habilis had completely evolved for a bipedal lifestyle. They also had larger brains at over 600 cubic centimeters.

Habilis were shaped differently, too. Their skulls were smoother and rounder compared to australopithecus, their faces projected less, and their teeth were smaller and narrower. Still, habilis were small compared to modern humans, averaging about 75 pounds. Their diet, as told by the Smithsonian, included hard to chew foods like woody plants. Habilis also ate meat, which is known because of tool and bone evidence. In fact, this species' name, Homo habilis, literally means "handy man." At the time of their discovery in 1964, it was thought that they were the earliest users of tools. However, it has been shown that australopithecus species may have been using tools earlier.

Homo habilis is often put forward as the ancestor of all other human species.

Homo erectus is well-known because a number of specimens of the species have been excavated. These date from between 1.89 million to 110,000 years ago, making it the longest existing species of human ever.

According to the "Origin of the Genus Homo," erectus had larger bodies and smaller teeth than Homo habilis. Also differentiating them from earlier human species were their proportions. The Smithsonian reports that erectus had the shorter arms and longer legs of a proportional modern human. Also, their height was comparable, ranging from 4 feet, 9 inches to just over 6 feet with an upward average weight of 150 pounds. Erectus were fully evolved to live a ground-based lifestyle.

What really differentiated erectus from earlier human species was brain size. Erectus' braincase ranged from 700 to 1,300 cubic centimeters. Since brains take up a lot of energy, erectus ate meat as well as plants. Erectus also used diverse tools that included handaxes and cleavers.

There were a couple of significant firsts for humans with erectus. First, it is likely that they were the first to use and control fire. Second, erectus was the first human to leave the African continent. Fossils of erectus have been found also in all parts of Asia, even as far east as Indonesia. It is likely that a population of erectus gave rise to the lineage of modern Homo sapiens.

In 2003, on the island of Flores in Indonesia, scientists made a remarkable discovery in the Liang Bua cave. As told by National Geographic, they found the remains of humans that stood about 3.5 feet tall and weighed at maximum 75 pounds, though the females could be as light as 35 pounds. This species of human was dubbed Homo floresiensis after the island, but they were quickly nicknamed hobbits. Smithsonian reports that this particular human species lived 100,000 to 50,000 years ago.

Floresiensis were diminutive. Their brains were about 426 cubic centimeters, which is a little over a third of the size of a modern human brain. Despite the small brain, floresiensis used weapons to hunt stegodon, a type of extinct pygmy elephant.

What scientists are trying to figure out is how floresiensis fits into the homo family tree. Some reason that floresiensis descended from Homo erectus and evolved into dwarfs, as many species do in island environments. Others, as reported by Live Science, have posited that they were modern humans who suffered from mutations. Yet this is countered by skeletal differences, such as a lack of a chin, in floresiensis. Other analysis suggests that floresiensis evolved from a different human species than erectus, which means that erectus would not have been the first human to migrate out of Africa. The debate will likely only continue as more research and excavation is done.

Homo antecessor is a debated human species. As detailed by the Australian Museum, the first remains of antecessor were uncovered by archaeologists between 1994 and 1996 in Atapuerca, Spain. Subsequent discoveries, also in Spain, have led scientists to date the species from 800,000 to 1.2 million years ago. This species was different from other human species, with a selection of traits that clearly show that it was related to modern humans. What were those traits?

The brain size of antecessor, while large at 1,000 cubic centimeters, was not particularly remarkable. Its height, which ranged from 5 feet, 2 inches to 5 feet, 9 inches made it very comparable to Homo heidelbergensis, as well as modern humans. Antecessor is thought to have led a hunting lifestyle with large amounts of weapons and tools found at dig sites.

Antecessors' facial features were definitely more modern, including projecting noses and modern cheek bone structure. However, they also had prominent brow ridges and a receding chin, features seen in other species of human. All the same, these facial features, according to Britannica, have let some scientists to classify antecessor as its own species. Smithsonian reports that some have argued that this species might have been the direct ancestor of modern humans, hence its name. However, some view Homo antecessor as merely a type of Homo heidelbergensis. It is likely that the matter will not get settled until more specimens are found.

The most well-known of all extinct humans is Homo Neanderthalensis, known popularly as Neanderthals (sometimes spelled Neandertals). These are usually considered stereotypical "cavemen." According to Britannica, Neanderthals first came on the scene about 200,000 years ago and lived until as recently as 24,000 years ago.

The Smithsonian explains that Neanderthals are probably the closest extinct relative to modern humans. Neanderthals were smaller than modern humans, with males being about 5 feet, 5 inches tall at 143 pounds and females 5 feet, 1 inch tall at 119 pounds. However, they were more robustly built, stronger, and had prominent noses. All of these were adaptations for the cold since Neanderthals lived from Western Europe to Central Asia during the Ice Ages. To cope with these conditions, they had a slate of advanced weapons and tools for hunting, gathering, and making clothes and shelter. This intelligence is reflected in their brain size, which according to Discover Magazine was about 1,410 cubic centimeters — larger than modern human brains. Neanderthals also displayed culture, through what appears to be formal burials, evidence of spiritual beliefs, and even possibly musical instruments. Archaeologists found what is possibly a flute at a Neanderthal dig site.

The reason Neanderthals went extinct is debated, although it is likely they were pushed out by modern humans. Still, recent genetic analysis shows that Neanderthals interbred with modern non-African humans. So in a way, Neanderthals never really went extinct.

Homo longi was first discovered as a nearly complete skull in northeastern China in 1933. However, according to Discover Magazine, it was treated no more than a curiosity. The skull was larger than modern humans and the brain size seemed to be comparable. Sci News reports that the skull also featured nearly square eye sockets and thick brow ridges.

However, no one worked out the puzzle of this skull until 2021, when researchers proposed that it was a new, unique human species. What's more, this specimen was alive, at minimum, 146,000 years ago. Analysis also makes scientists believe that this particular skull belonged to a 50-year-old male living in a community in a forested floodplain. Some scientists contend that this species would be the closest extinct relative to modern humans. However, as the New Scientist points out, this claim is highly contested, with others believing that Homo longi is a Denisovan. More specimens would need to be recovered and compared to determine if this is truly a new species.