I'm one who can't be of any help in that regard, Niels. Our guide, Fernando, must have told us; he spoke some English, as I remember and had a good supply of facts to relate. I can't find in my notes anything about which species were there.
I assume we went to the same place. Does this photo of the cave we visited look familiar? It was at the bottom of a pretty deep and wide cenote. Here is an excerpt from a trip report I never posted:
Several minutes after the flight of the initial group of bats flew from the hole, the main colony began to emerge. They not only poured out of the cave entrance but every crevice in the limestone walls. In less than 30 seconds, a funnel of bats began to form as they swarmed, circled and ascended; hundreds and hundreds of bats in an accelerating number coming from every possible direction. The bat funnel created its own breeze and their aroma tainted the air. Fernando covers his mouth with a bandanna to avoid breathing in a bacterial infection, (histoplasmosis), that the bats can pass on. Bats continued to stream out of the cenote in a wild, swirling mass, estimated at close to 6 million bats of 14 species. We were there, dodging bats and taking pictures in the dim light for at least 15 minutes, and still they streamed out. They would continue to emerge for hours, our guide told us, each species at different times. We leave them to their nightly exodus and drive back towards camp.
The number of species must have come from Fernando. An amazing experience!
Steve