A. afarensis lived in eastern Africa between 3 and 4 million years ago. This australopithecine had a brain size a little larger than chimpanzees. Some had canine teeth more sticking out than those of later hominines. No tools of any kind have been found with A. afarensis fossils. According to Microsoft Encarta Encyclopedia ’98, between about 2.5 million and 3 million years ago, A. afarensis clearly evolved into A. africanus.
Anamensis is thought to have existed between 4.2 and 3.9 million years ago. The teeth and jaws are very similar to those of older fossil apes. A partial tibia supports bipedality. The first fossil of this species was found in Kanapoi Kenya by Bryan Patterson. The fossil was a lower left humerous dated to be about 4.0 million years old.
There are a number of fossils that have been found throughout the researchers journeys. One of them is called Ardipithecus ramidus. It is the oldest known hominid species, found in Aramis, Ethiopia in 1994 by Tim White. Most remains are skull fragments. Indirect evidence suggests that it was possibly bipedal, and that some individuals were about 4'0 tall.
The population of Homo antecessor that remained in Africa evolved into Homo sapiens. Another possibility is that Homo antecessor is ancestral to both Homo sapiens and Homo neanderthalensis. The Neanderthal was not human. Genetic evidence from a comparison of human and Neanderthal mitochondria shows that while chimpanzee and human lineage's diverged four million years ago, the Neanderthals diverged over 550,000 to 690,000 years ago. Human trunk and limb bones of Homo antecessor, recovered from the Ran Doling site, in the Sierra de Atapuerca have been dated at about 780,000 old and are said to represent the last common ancestor for Homo sapiens and Homo neanderthalensis.
compared to living humans today (Relethford, 2010). Post cranial skeleton show similarities to Austrapiths and an evidence to bipedalism however, they retained climbing abilities ( McHenry 1992). The simple stone tools found associated with Homo habilis were referred to as Oldowan tools. There is still no clear evidence whether these species relied on scavengers left by the carnivores or did they associate themselves in hunting by the use of the stone tools ( Relethford, 2010). Apart from Homo habilis, Homo erectus was also found in East Africa around 1.9 million years ago (Relethford, 2010).
The cranium has been designated TM 266-01-060-1 (Wood). Only two other hominid fossils have been found in Chad. The first, which was found in 1961, turned out to be a modern human skull that had become so eroded that is looked like an australopith (an early form of hominids). The second set of remains was found in 1995. This hominid was a real australopith and was named Australopithecus bahrelghazali (Wood).
The Austalopithicus was found in African and was know to have lived from 4.2 to around 1.0 million years ago (Standford 251). They had a small body like an ape that would get approximately 64 to around 100 pounds. They had a big jaw with a U-shaped mouth of small teeth. The brain size of a Australopithicus was small and would get approximately 340 to 500 cc, which is in the same range as gorillas and chimpanzees brain sizes. The top of their skull was of a bony ridge.
The Pachycephalosaurs were considered to be bipedal. They were also found to have thick skulls, flattened bodies, and tail that were covered in an array of body rods. Pachycephalosaurs were thought to have been more than fifteen feet long and processed a skull that was surrounded by a rounded dome of solid bone. It was thought that they used their heads in combat or mating contests, but that was disproved fairly recently, which I will discuss later in the paper. Both Ceratopsians and Pachycephalosaurs were “bird-hipped” and both of these suborders contained a backwards pubic bone.
Wilford states “just as people look different from one another today, so did early homonids” (Wilford 2013). Another aspect to consider is the fact that skull 5 was found outside of Africa suggesting that brain size might not have been the primary driving force of migration because the fossil know as skull 5 had a smaller braincase than Homo erectus (Wilford 2013). Homo erectus was believed to be the only Homo to have left Africa (Price and Feinman 2013). This find can result in one of two conclusions. Firstly, only one type of homo existed during this time period bundling up habilis, erectus, and other variations of erectus into one; and secondly, that early hominids other than erectus likely migrated out of Africa contrary to what is currently believed.
The lack of cranial fossils for 2 million years is a problem. We do not know what took place during this time. The first available cranial fossils are those of A. afarensis. The mean endo cranial capacity was 413.5 cm3, which means that its brain size was that of today’s African great apes (Changeux and Chavaillon pg. 65, table 4.1).