Apropos of last week's post on models and data, here is a preprint study on the amount of morphological data available for living mammal taxa. The focus was on coverage in each order, where coverage was defined by the fraction of OTUs with available data, where available seems to be defined as appearing in a character matrix with more than 100 characters (which doesn't necessarily mean that >100 characters were scored for each OTU). I can't judge whether the three databases and the literature search constitute a sufficient search, but their results aren't implausible. Using their appearance in a sufficiently character-rich matrix, they counted 1074 mammalian OTUs in 126 matrices. Without the matrix size filtering, there were 5228 OTUs in 286 matrices. This is apparently less than the morphology data for fossil mammal taxa.
I expect there are very few character matrices for any group with more than 100 behavioral characters. This is probably a combination of the difficulty of extracting a 100 behavioral characters in a study as well as the rarity of this sort of comparative/phylogenetic analysis in behavior.
Thanks for to everyone who responded to last week's post.