There hasn’t been a ton of great information about the Bili ape because the research is being done in the Democratic Republic of Congo where they have a lot of civil wars, poachers around the area, not to mention Ebola. Some of the initial reports were that the chimps were up to six foot six in height, which is the height of many professional basketball players, and that would be gigantic. Imagine a chimpanzee that tall. But, now they’re saying that they get up to five foot five inches in height, which isn’t nearly as tall, but is still taller than the conventional chimpanzees most people are aware.
Another thing was that they were lion killers and there’s no evidence of that because they’ve done a lot of scat tests where they determine what the chimps were eating and there’s no traces of any type of big cat meat. They say that although there has been a report that Bili apes have scavenged a leopard at one time there is no strong evidence that they killed lions or eat lions or leopards, and certainly not on a regular basis.
Another thing was that they were half chimpanzee, half gorilla, some kind of hybrid, but now the reports are that they have a close relationship with the eastern chimpanzee, which is Pan troglodytes, so they’re not related to the bonobos directly but more the conventional chimpanzee, which most people are already aware of.
To see what an actual hybrid between the gorilla and the chimpanzee would look like take a look at these morphs. One of the most obvious things when you start off with a chimpanzee and morph it to a gorilla is the ear size. The chimpanzees have giant floppy ears. Of course, their ears vary from chimpanzee to chimpanzee and the bonobos have different ears than the conventional chimpanzee, the Pan troglodytes chimpanzee, which is related to the Billy ape. Gorillas tend to have much smaller ears and not a lot of variation between their ears, they all have small ears.
The other big thing is gorillas have a much bigger head and a lot of that trapezius in the back of the skull and their giant neck muscles is kind of lumped in with their head because this looks like one big mass and from the side you see their head the giant crest in their head and the giant neck muscles, it looks like one big mass sitting on top of their shoulders. The chimpanzees do have a sagittal crest but sometimes from the front it actually looks recessed because they have all these muscles on the side of their head that are anchored to the sagittal crest, and they actually stickout more. They’re higher as opposed to the gorillas where the sagittal crest is higher. The chimpanzees crest is actually lower. You see that in a lot of photographs of chimpanzees especially some that are bald. You can see that in bold relief.
Another thing is the chimpanzees have a bigger muzzle. That might not be all bone structure. Maybe that’s fleshy tissue, but their mouths tend to stick out more just kind of like their ears, they have floppy mouths. Chimpanzees do, and they have floppy ears as well there are similarities between the noses the bridge of the nose the chimpanzees are a little broader and the gorillas have a thin bridge to the nose but there’s not a lot of difference between their noses. Gorillas noses tends to go down closer to the mouth. There’s not a lot of distance between the lips and the lowest part of the nose on the gorilla. Not so much with the Chimpanzees. There’s more, you know, mug, orbicular oris, the muscle that goes around the mouth. You can see the that whole area is between the lowest part of the nose and the lip is taller in the chimpanzee than the gorilla.
The gorillas seem to have smaller eyes, at least in proportion to their whole head. They both have ample brow ridges but the gorilla seems to edge them out with heavier brow ridges and just generally more protection around the eyes. Their forehead looms out more and their cheekbones come forward a little bit more than the chimpanzee. Also, bigger jaws on the gorilla.
Another thing that’s kind of subtle if you look under the lip as it morphs back and forth between the chimpanzee and gorilla the mentalis muscle seems to stand out more. That’s that round muscle when you pout your lips. That kind of a ball shape, circle shape muscle on top of your chin that kind of dimples. You can see that more in the gorilla than you do in the chimpanzee.
Is there anything that I’m not picking up on and this is just form-wise, not necessarily pigmentation-wise. This is just the general form of the gorilla versus the chimpanzee but can you see anything else? I can do this with Neanderthals versus a modern human or going back further in time to Australopithecus versus a modern human or a chimpanzee versus a modern human or I could do it with, you know, political figures, just joke ones, a CNN reporter a politician or anybody versus a chimpanzee or versus another person. This morphing, going back and forth between the two is a great way to study the differences. It’s a greatcomparative anatomy tool. I haven’t really seen it used that much and what comparative anatomy do you want to see?