monkeys have a grammar

If the researchers mentioned in these three articles are correct in their analysis, then these putty-nosed monkeys actually combine morphemes to make different meanings. According to conventional thinking about "language," this is not supposed to be attested.

However, if you intuit, like me, that there's nothing special about language vis a vis the Human brain, then this is not really exciting news (unless you plan to use it as a piece of evidence to change non-believers' minds).