Nicholas M. Hellmuth the term "dragon" is appropriate at times to describe crocodiles or caimans.
Nicholas M. Hellmuth, “Crocodiles, caimans and alligators in Mayan art and mythology of Guatemala” Revue: Guatemala’s English Language Magazine (November 10, 2011), 94
Other misidentifications
Since most Mayan scholars don’t live with a crocodile or caiman in their home, it is not surprising that these reptiles are often innocently misidentified. Several of the supposed crocodiles in Mayan murals are much more likely iguanas or other lizards.
Part of the cause for misidentifications is that many creatures in Mayan art are composites: part of one creature with attributes of another.
Yes, you can find surprisingly realistic crocodiles or caiman (the crocodile trees of Izapa, Chiapas, are pretty naturalistic for the body scales), but most crocodiles have distorted scrolled snouts and exaggerated supraorbital plates. Actually, “dragon” is a term that is not always inappropriate.