After several behind-the-scenes and Online discussions with Tyer Stone on the matter, I have a few suggestions on what the skeletal anatomy of the Freshwater Monkeys are like. They are basically large macaques on a par with the bigger macaques such as the bear monkeys o Southeast Asia, and there are big males which are about normal human size seen commonly in the USA. This may be a geographical variation or it may be a new development triggered in response to environmental disturbances by humans. Traditionally, the creatures are usually small (3-5 feet tall being a common general range of estimations) they are very powerful swimmers and divers relying primarily upon their very developed hind legs and large flipperlike feet, either of which are often compared to the legs and feet of frogs. It would seem that their feet are disproportionately large in conparison with most human beings and even bigfoot: whereas a human being's height might commonly be seven times the length of the foot and a Bigfoot's height more like a sixth, in the case of the Freshwater monkeys it is probably more like a fifth of the height or even larger. The crreatures are also possessed of very large, bulging, glassy and reflective eyes, usually heavily lidded in daylight, which also remind witnesses of frogs or lizards. The head is surrounded by a prominent ruff or mane of hair all around, but coming out in all directions from the center of the top of the head, which therefore has something which looks like a depression or a bald spot.
I would imagine that the weight of a FW monkey that left a humansized track would be less than half the weight of the human, the actual weightbearing part of the foot is quite small in comparison. So if you had a 12 inch FW monkey track it would go with a five foot tall FW Monkey and it would weigh less than a chimpanzee at the same height, perhaps 75 to 85 pounds. The usual FW Monkeys would be smaller than that and range usually 15 to 30 kg or 30 to 60 pounds approx.
BTW, if I am correct in my re-assessment of the proportions, "Momo" would be closer to five feet tall rather than the reported seven feet or more. In discussing similar reports, Loren Coleman also noticed that the common run of NAPES sightings were less than human size but some sightings said seven feet or more. He then quoted Heuvelmans as saying 'A hair-covered creature always seems larger than it really is' in regards a report of a 7-foot-tall monster that had left a 10-inch track: we are dealing with exactly that situation again in the case of Momo and the Fouke Monster. In other words, the North American variant of Freshwater Monkeys might not actually be outsized as compared to other populations, only reported as being so.
..And just because I had it handy, a cast of one of those lopsided coyote tracks I was talking about.
Best Wishes, Dale D.