The Maya writing system is correctly called “hieroglyphs,” that is, “sacred writing,” because, according to their own writings, they believe their writing system was given to them by the gods.
I have that book on request at the library right now. It might even arrive before I get there this afternoon.
There is a technical distinction according to Coe between the Mayan glyphs and hieroglyphs. IIRC, the Mayan glyphs express phonemes while hieroglyphs represent words.
I’d say their writing was a bit on the difficult side.