Scientists have found two new crocodile species off the coast of the Yucatán

Their new study reveals that the island of Cozumel and Banco Chinchorro Atoll off the Yucatan coast are home to two entirely new species of crocodiles, previously thought to be common members of Crocodylus acutus.

Details: Jose Avila-Cervantes et al, Novel island species elucidate a species complex of Neotropical crocodiles, Molecular Phylogenetics and Evolution (2025). DOI: 10.1016/j.ympev.2025.108341

🐊 Two new crocodilians: who are they?

A team of scientists from McGill University, along with Mexican colleagues, made an unexpected discovery. They found two crocodile species unknown to science - one living on the island of Cozumel and the other on the Banco Chinchorro Atoll, near the Yucatan Peninsula.

This discovery seriously shook up previous ideas about the well-known American crocodile (Crocodylus acutus). Until now, the species was thought to have spread from Baja California to Venezuela and throughout the Caribbean. However, a new study has revealed: there were actually separate species lurking out there!

🐊 How were they found?

Biologists led by Professor Hans Larsson analysed the genetic material of crocodiles from Cosumel and Banco Chinchorro. When they compared it with the DNA of other crocodiles from the Caribbean, Central America and the Pacific coast of Mexico, they found striking differences. It turned out that these are not variants of the same species at all, but completely separate crocodiles. The new species have not yet been named.

"We were shocked by the result," admitted the study's lead author Jose Avila-Servantes, Larsson's former PhD student. - "We thought Crocodylus acutus was one big family. And now it's clear that behind this name there is a whole complex of different species."

🐊 Why is this important?

Newcomers to the crocodile world live in tiny, isolated populations - less than 1,000 adults on each island. Although these populations are now stable, their situation is very fragile: their limited territories make them vulnerable to any change.

"Biodiversity is disappearing faster than we have time to study it," warns Professor Larsson. - "To protect rare animals, we need to first find out exactly what we stand to lose."

Thescientists emphasise: now that it is clear that these are individual species, action must be taken urgently. Limiting coastal development and creating protected areas on Cosumel and Banco Chinchorro could save the new crocodiles from extinction.