A glance at the evolutionary family tree of humans reveals that the three earliest-known branches ae full of species that appear far more ape-like than the "caveman" stereotype associated with the Homo branch. Some of these strange-looking guys and gals are evolutionary ancestors of humans, but others might be hominids that just co-existed with the ancestors of modern humans, meaning we're related, but we didn't necessarily evolve from them.
Thanks to the efforts of talented sculptors and scientists, we can look at models of these early hominids in museums and online, but the truth is that most of what we know about these species is from a few scattered bone fragments. The fossil record has been filled in tremendously since the first findings in the 1920s, so we're learning an extraordinary amount about the history of human evolution each year. Read on for a brief tour of the major hominids that predated the branch that eventually lead to Homo sapiens (that's you!).
Paranthropus Aethiopicus: Branching Out
Little is known about Paranthropus aethiopicus, but many scientists believe it is the earliest example of a so-called "robust" australopithecine, meaning it has a strongly protruding face, large teeth, and a powerful jaw for chewing its largely vegetarian diet. The Paranthropus species is considered to be a "side branch" of human evolution that did not lead to Homo sapiens. The 2.5-million-year-old "Black Skull" find of 1985, named because of the dark minerals it absorbed while fossilizing, is the only known adult skull of P. aethiopicus. The find validated the recognition of the species at a time when many scientists thought Paranthropus robustus and Paranthropus boisei to be the only known robust australopithecine hominids.
Paranthropus Boisei: Nutcracker Man
Nicknamed "Nutcracker Man" for its massive cheek teeth and large chewing muscles. the 1.2- to 2.3-million-year-old Paranthropus boisei is another robust australopithecine hominid that co-existed with other species of early humans in a "side branch" that did not lead to Homo sapiens. In 1975, in fact, a P. boisei specimen and a Homo erectus specimen were found in the same layer of rock - the first recorded example of two hominid species coexisting. So what happened to P. boisei? Considering its highly specialized features, including cheek teeth four times the size of modern humans, some scientists speculate that the food they depended on for sustenance may have died out during their million-year run on this planet, thanks to intense climate change.
Paranthropus Robustus: Beside Man
The youngest members of the Paranthropus genus at about 1.8 to 1.2 million years old, Paranthropus robustus was also the first to be discovered when scientist Robert Broom bought a jaw fragment and molar in 1938 unlike anything he'd seen before. This led to the classification of a hominid species that branched off and co-existed with other early humans (Paranthropus means "beside man"). P. robustus was likely an omnivore and possibly a tool-user: bone fragments with polished ends associated with P. robustus fossils may have been used to dig for termites, a nutritious, protein-packed meal. One of the most complete early hominid skulls ever found, nicknamed Eurydice, belonged to a member of the Paranthropus robustus species.