article_snippet: They had brains no larger than a chimpanzee's .
article_snippet: - Paranthropus, lived in woods and had massive jaws for chewing .
article_snippet: The researchers, whose work on the fossil is published in the journal Science, say the fossil could be a key missing link between the Homo lineage and a more primitive and ape-like rival branch of the hominin evolutionary tree called Australopithecus.
article_snippet: Details of the Australopithecus are best known from a fossil named ‘Lucy’, dating back 3.2 million years, which was discovered in Ethiopia in 1974.
article_snippet: student Chalachew Seyoum said student Chalachew Seyoum was ‘stunned’ when student Chalachew Seyoum saw the fossil.
article_snippet: The moment I found the fossil, I realised that the fossil was important, as this is the time period represented by few fossils in Eastern Africa,’ student Chalachew Seyoum told BBC News last night.
article_snippet: Dating of the fossil and the surrounding sediment suggest the fossil is between 2.8 million and 2.75 million years old.
article_snippet: Other fossils of antelope, prehistoric elephants and hippos discovered alongside the new jawbone suggest that this early Homo species lived in open grassland and shrub habitats.
article_snippet: This matches the picture that scientists believe was occurring around this time of climate change creating increasingly arid conditions in Africa.
article_snippet: Australopithecus, by contrast, was thought to inhabit far wetter environments and this may have contributed to The researchers eventual demise.
article_snippet: Finds like Kenyanthropus (a 3.5 million year old ape-like species) have made it harder to understand the relationship between the Australopithecines and us - in short
article_snippet: The new fossil may well be a member of our genus, an australopithecine or an hitherto unknown genus.'