I think that website is stretching a bit. Snakes can be found all over the world. Ancient people may have had telescopes but I don't think they
were powerful enough to pick up details on Jupiter. The Mound Builders and Egyptians were two totally different cultures nearly half a world away
from each other.
bc] The serpent is not a snake, and you don't find snakes mouthing an egg, and you don't find references to them in the Pyramid Texts, and the Book
of the Dead. And there's no likeness between a snake and the Eye of Horus!
There's always the question when discoveries are made: Who made the serpent mound of Adams County, Ohio?.
In answer there's the tendency for investigators [because it represents the least amount of work .. and it's the least likely to step on orthodox
toes] to assign it to the area's indigenous people.
But in the case of the serpent mound .. it was not the work of the
area's indigenous people. The mound represents a concept that has never been discovered in the myths of Ohio.