Who's Who Among the Early Hominins

Who is who among early hominids?
by Randall Susman
Odyseey: Adventures in Science

Article Summary:

There are so many types of our past ancestor but how much do we really know about them, and are we sure about what we already know. Early hominids are many times called ape-men, that's because of the characteristics they have in common with apes and humans. Their skulls, teeth and limbs remind us of apes, but that they walked bipedal makes them similar to humans. The fossil record shows both primitive (ape-like) and advanced (human-like) features. The earliest hominins include sahelanthropus tchadensis, Orrorin tugenensis and Ardipithecus. 

There are many species of early hominids, the earliest species is the Sahelanthropus which was discovered in Chad, a country in north-Africa in 2001. It is between 6-7 million years old. And it may be closer to apes than to bipedal humans. The Orrorin was found in Kenya, a country in east-central Africa. It is the oldest definitive hominin, and it is between 6.1 and 5.8 million years ago. It had bipedal and climbing skills. Primitive bipeds that  climbed on trees looked for food and to escape danger. And also the Ardipithecus. It dates back to 4.4 m.y.a. It has primitive, ape-like,  skeletal anatomy with small molar teeth and large front teeth. 

Other species are the kenyapithacus platyops were found in 2001, near lake Turkana in northern Kenya, and it dates back around 3.5 m.y.a. The Australopithacus was found in east and south Africa. The fossils dates back to more that 4 m.y.a. to 2 m.y.a. Two species of this group Australopithacus anamensis and austrolapithacus afarensis are the most ancient australopithacines. A third species austrolapithacus africanus is more recent. Found in south Africa, it dates between 3 and 3 m.y.a. Compared to the later hominins, austrolapithacus have small brains, large molars, long upper limbs and short lower limbs, and big difference in sizes between male and female. But anyway austrolapithacus were more like humans than apes because they walked on their 2 legs. The Paranthropus are similar to humans. It existed at the same time as A.africanus, and the early Homo sapians. It was bipedal and probably spent more time on the ground than A.africanus and and A.afarensis. It ate mainly grass and other plants, while Austrolapithacus ate both plants and animals. Paranthropus robustus come from a series of limestones caves in South Africa. P.robostur had huge molars and premolars with small front teeth. Scientists learned that P.robostus ate hard plant food and took in sand and grit with their vegetarian diet. It is about similar in size and weight to A.africanus, p.robostus had large jaws and teeth (the word robostus means strong and hardy). The structure of parathropuses hands showed that it used stone tools and bones, and might have made them.

 The early Homo refers to the first member of our own group. Earlier fossils date to 2 m.y.a and were found in East south Africa. They had larger brains, but smaller teeth, faces, crests on their skulls and more human-like hands, and feet, than austrolapithacus and panthropus. They use simple stone tools. Homo habilis can be divided into 2 species, h.habilis and h.rudolfensis. 

Homo habilis has a larger brain, and smaller narrower premolar teeth, than austrolapithacus or paranthropus. Because of its larger brain its teeth and certain human like features, H.habilis is more human like than the austrolapithacines. Features of the hand and foot, as  well as the proportions of the upper and lower limbs show that h.habilis was bipedal working with tools, and a tree climber. Homo rudolfensis is in the same period as h.habilis. It has a large brain and a broad flat face and cheek bones. The molar and premolar teeth are broader than those of H.habilis. 

Another name for Homo erectus is advanced. It dates back to 1.8 m.y.a. It is found in Africa, Asia and Europe. It has smaller molars and premolars and smaller jaws than astrolopithecines and H.habilis. They had larger brains with thick skull bones and prominent brow ridges. Taller and heavier than any other early hominin. Fossils of these species is found in sites with more complex tools, mammal bones, sign of hunting, fire and primitive dwelling. Homo Georgicus dates back around 1.8 m.y.a. Damansis hominins are closer to h.habilis in brain size. Homo floresiensis were discovered on the island of Flores in Indonesia. The stone tools date back to 94,000 years, but the skeletal remains date around 18,000 years. And lastly the Homo Neaderthals. A hominin species that lived in Europe and central Asia from 2250,000 to 30,000 years ago. They had good stone tools and other culture. Their skull was 3 times that of the australopithecines and twice as big as the earliest Homo sapians. Their body size is the same as the modern human. They are considered as a subspecies of homo sapians and the sister group of fully modern humans, H.Sapians.
There are so many early hominins out there, ones we weren't even aware for, and so much more facts about those that we do know.

Susman, Randall. "Who's Who Among The Early Hominins." Odessey: Adventures In Science Oct. 2009: 

22-25. Print.