Two potential types of inaccurate, termite feeding Alvarezsaurid
You might want to brace yourselves, I'm here with another inaccurate suggestion.
The Termites
This one sort of goes hand in hand with the situation of termites being a major feature of an insect feeder.
The only Costa Rican termite I could find is
Nasutitermes corniger (conehead termites), an arboreal nesting termite, some examples of the nests below:
In reality
Nasutitermes probably aren't the best for feeding on generally, due to the chemical defenses of their soldiers. Alvarezsaurids also, assuming they fed on termites, likely scratched at tree bark, rather than the mounds themselves, but that wouldn't really be as much to look at for a feeder in my opinion, though a fallen log may fit the purpose of it as well, being more general feed, with other insects and such.
Type 1 Alvarezsaurid (Mononykus/Shuvuuia base)
This one uses the Mononykus reconstruction by Scott Hartman, with him using the skull and some other characters from Shuvuuia (as it's the only Alvarezsaurid skull known at the time & as far as I know). To aid in termite feeding I've given both of these an extended tongue and nictitating membranes over the eyes.
Free tongues in general aren't considered accurate, with bird like tongues only being present in Paraves to our knowledge. Alvarezsaurids don't exactly have well preserved enough skulls to compare it, but it's still quite unlikely. Longer than jaw tongues in birds also seem to require significant skull modifications, just to store them in the skull, as seen in Hummingbirds and Woodpeckers (with the forked back of the tongue modified in both cases).
Tongues are normal for the game dinosaurs (kind of canon as well), so a couple might as well use them for something. The tongue and slight under bite of this one are influenced by Numbats.
The wrists of both of these are also rotated 90 degrees (maybe even more, not really sure), which would allow for a sort of doggy paddle, raking action when raised against a termite mound (a more accurate sideways action might require more movement, animation wise, but they are probably about the same, I just figured that this is just a Jurassic Park-ism anyway).
Type 2 Alvarezsaurid (Alvarezsaurus base, more extreme)
As you might be able to tell, this one takes a fair bit of influence from the South American Anteaters. It's extreme enough that I'd only really be comfortable with
Alvarezsaurus or
Bonapartenykus taking this form.
Bonapartenykus is the largest Alvarezsaurid, being estimated at 3 metres in length, as opposed to the largest Asian one,
Mononykus, being a little over 1 metre in length. If both types of Alvarezsaurid I've proposed were considered, then a size difference might be good, even if it's small.
Stength wise, the Asian Alvarezsaurids are likely stronger proportionally than the South American ones, due to the shapes of their shoulder blades.
