Day 293# (part 2): Paranthropus robustus
Today's animal of the day is Paranthropus robustus!
Image credit: Michael Long
Alright, here's the real animal of the day, Paranthropus robustus! Which is basically the closest thing we'll ever get to a real-life Bigfoot. This extinct species of great ape lived during the Middle Pleistocene epoch, around 1-2 million years ago, in what is now South Africa. It was first discovered in 1938 by a teenage boy named Gert Terblanche, who found a handful of super weird teeth and a few fragmentary bits of skull in what would eventually be known as the Kromdraai Fossil Site. News of this discovery would eventually reach paleontologist Robert Broom, who apparently approached Gert at school one day and traded him five chocolate bars in exchange for the teeth. As a teacher, I would be very concerned if I saw a strange man offer a teenager candy in exchange for teeth, but that's just me. Broom also had Gert lead him to where he found the bones, which led to the discovery of a more complete skull.
Photo credit: Ditsong National Museum of Natural History
Since then, many more Paranthropus specimens would be discovered in and around the Kromdraai formation, and eventually several different species would be described. However, P. robustus was the first and is considered the type species, so I'll save the other Paranthropus species for another day. The name Paranthropus means "near man" since the bones look very similar to those of early (and modern) humans, while the robust part of their name refers to how absolutely massive their back molars were. These giant chompers, combined with their wide cheeks and the sagittal crest on top of their heads that would've helped support strong jaw muscles, have led paleontologists to believe that Paranthropus would've fed mostly on tough plants, like grasses, that require powerful jaw muscles and large grinding molars in order to chew.
Photo credit: John Gurche
Like humans, Paranthropus is believed to have been bipedal and would've walked upright just like we do. In fact, Paranthropus is considered to be the sister genus to our genus (Homo) since both Paranthropus and Homo are believed to have split off from Australopithecus around 3 to 4 million years ago. It seems that while Homo evolved a more generalist lifestyle, with big brains and small teeth, Paranthropus evolved a more niche lifestyle where they fed on tough-to-chew plants that other Hominids would avoid. This is known as niche partitioning and helps two very similar species avoid competition with each other, thus allowing them to inhabit the same area at the same time.
Photo credit: John Reader
However, recent evidence suggests that not every species of Paranthropus would've only eaten tough grass and nuts. Some would've eaten much softer plants, and there's even potential evidence of Paranthropus using stone tools to kill and then cut up hippos! But there's still some debate over that particular fossil site, and technically, the species of Paranthropus there is P. boisei, not P. robustus, so I'll go into further detail about that some other day. Though I will say that I think it's 100% likely that Paranthropus would've definitely eaten more than just grass. It's very rare in nature for an animal to eat just one type of thing, since whenever that food source disappears, you're suddenly left with nothing to eat. So, it's extremely likely that while Paranthropus mainly ate grasses and other plants to avoid competition with other Hominids, it probably would've also eaten other foods, such as insects, honey, fruit, and meat when given the chance.
Image credit: Jay Matternes
In addition to being these weird cow versions of great apes, Paranthropus robustus was also sexually dimorphic, with males having larger cheekbones and being a little taller at 4 ft 4 in, while females were around 3 ft 7 in. While the exact type of social structure of Paranthropus is unknown, it's theorized that it might have lived in gorilla-like harems where there's one dominant male living with several females or in baboon-like groups where there can be multiple males in the same group. Either way, it seems that younger males would've been kicked out and made to find or form their own groups, since there are many more male fossils than females, which seems to suggest there was a higher male mortality rate. The environment that Paranthropus would have lived in was a mix of open savannahs and sparse woodlands, and it would have lived alongside animals like hyenas, leopards, sabertooth cats, and early members of the genus homo. Sorry if these guys aren't exactly like Bigfoot, but I personally love these guys. I think early humans/human relatives are all super interesting, and I wish at least some of them were still around.