maaau ("almost my people") are the closest living relatives to maanuls.
They share the same tribe, but not the same genus. Species of the same genus as modern maanuls are extinct. Mainly through diseases, genetic bottlenecks, hybridization, inability to survive environmental changes, food sources going extinct, species competition during famine related to food source extinctions, etc.
Contradictory to spread out in-world belief due to a poor understanding of natural history in the general population, Maaaus isn't an ancestor who'm maanuls evolved from. They are their own species, who evolved alongside maanuls but for a different available niche. They do descend from a common ancestor who arrived at the western coast millions of years ago. And said ancestor was closer to the current family the kyhuines species belong to, than modern maanuls and maaus are.
While maanuls, kyhuines and mierthri may be called "cousin species" by me all around my blog, they are several sub-orders away from each others. So it is somewhat of a stretch at times, and more of an in-world thing to say. Some places will consider kyhuines and mierthri more of a cousin to maanuls than maaaus are, when biologically speaking maaaus is their closest living cousin, not them.
The distinction here is a social one they made up, in modern languages the distinction between a maanul, kyhuine, or mierthri isn't distinct, as they will share the common word that roughly translates to "people". Distinctions will be done via using other words if needed, such as in the medical field for example.

During early world history, many groups of Maanuls didn't know maaaus existed for a while. as the species itself is by default is extremely shy, and avoid being seen for it's own protection. Groups who interacted with them more weren't necessarily in contact with those unaware of the species.
There was rumors of "little people" that would run into the reeds if it was spotted. Most people wouldn't believing it as no specimens were caught yet. The myth of "gnomes" originate from early sightings of maaaus from mainly children or intoxicated people. Gnomes in nuinuk art (place where this folkloric and mythological creature takes a large role here) resemble a maaau with a maanul face and no arms. People confused their constant tucked arms for a lack of them.
It is considered that there are 4 species of maaaus. Knaan maaau (vague term for west coasts) or more commonly referred by Juaan maaau, is considered to be the ancestor of the other 3 species. Pigmy, Domesticated maaau, and inland maaau are the result of maanul interacting with the species. By either domestication or just picking them to be on their boat during travel, and then introducing them to new environments.
While there are more species living of maaaus than maanuls, maaau's have a much smaller world range than their larger cousin maanuls. Who have spread out on most coastlines, thousands of islands, inland seas regions, some maanul populations even remaining in the artic sea all year. The original range maaaus had was quite small, more than half of their modern range is from maanul interactions.
thank you for reading. Here is a maanul sitting down and showing off a maaau to a mierthri. mierthri and maaaus are almost the same size. maaaus have a longer neck and legs.
Some additional doodles can be found under the cut of the tumblr post as a treat