First thing I thought of when seeing your new graphic - the Mayan hieroglyphs
Going down a deeper rabbit hole:
The macaw and quetzal were important figures in Mayan culture.
The graphic also resembles some headdresses depicted in Mayan art or the partial profile of a Mayan's face with a headdress.
Incidentally the
Rhea (aka. ñandú guazu) is a flightless bird of South America.
Tangentially, the codex refers to myths like El Dorado and Prester John. That got me thinking about the ancient
Muisca people. Like the
El Dorado wiki explains, the account of an
appointment of a new ruler with a ceremony of discarding
gold items into Lake Guatavita seems similar to Prester John ruling a
kingdom of "riches, marvels and strange creatures".
The spanish Quest of El Dorado poem talks about "An alien Indian, hailing from afar,
" which, given their terms for foreign ethnicities, could be a link in the codex with Prester John, who was also a king of the east (ie. a foreign / distant land). This also shares a link with an unfortunate European interpretation of Atlantis being related to Mayan culture.
Despite the dark discriminatory implications, if you look at these myths, they all seem to derive from a colonial perspective of yearning to find a more advanced / prosperous / glorious ancient progenitor culture that came before current "lesser" cultures.
Perhaps it is symbolic of what Raxxla could be? You could infer that Raxxla is the most advanced element of ED, and if it is unique from all the alien races we know of, then it would fit with the idea of a progenitor civilisation.