Twan Leenders, an accomplished herpetologist and author of the Guide to the Amphibians and Reptiles of Costa Rica (and some other books on reptiles and amphibians in Costa Rica), helped me identifying this species.
I met Twan during my visit to the Biological Station Rara Avis (now an Eco Lodge) in the Braulio Carrillo National Park in Costa Rica in 2003 and ever since I sometimes ask his assistance in identifying reptiles and amphibians that I have seen that I have seen but not been able to 100% identify.

1st photo: Biological Station Las Guacamayas, Parque Naturel Laguna del Tigre, Petén, Guatemala, 22 January 2020
2nd photo: Biological Station Las Guacamayas, Parque Naturel Laguna del Tigre, Petén, Guatemala, 21 January 2020
3rd & 4th photo: Tikal, Petén, Guatemala, 23 January 2020