Change based on synonymy in A Cumulative Checklist for the Lichen-forming, Lichenicolous and Allied Fungi of the Continental United States and Canada, Version 21, which in turn is based on Arup et al. (2013).

Arup et al. have this to say about the genus Xanthocarpia:

This mainly crustose genus is characterized, with one exception, by spores with a thin septum. ere are other groups, e.g. the genus Cerothallia, with these characteristics but Xanthocarpia seems to be well-delimited and the spore traits have developed independently from each other in the genera. In the phylogenetic analysis this fairly species-rich clade consists of mainly European species, but it will certainly expand in the future to accommodate more Asian and North American species.