Scientists Found Two New Crocodile Species Hiding in Plain Sight

• Scientists know of four New World crocodile species, but a new study highlights potential fifth and sixth additions to the reptilian family.
• The two new crocodile species are each endemic to an island off the coast of the Yucatán—the tourist hotspot Cozumel and the atoll Banco Chinchorro.
• Although stable, the populations are small and are immensely vulnerable to habitat destruction.

Of the estimated 8.7 million animal species on Earth, only 1.2 million of them have been officially described, with around 18,000 new species being discovered every year. Many of those are new kinds of jumping spiders, worms, insects, and other wriggling arthropods—the most abundant phylum in the animal kingdom. Huge reptiles don’t typically make the list.

However, a team of scientists from Canada, Mexico, and Panama claims they’ve discovered two previously unknown crocodile species off the Yucatán coast in a new study. With the four known species of New World crocodiles—the American, Morelet’s, Cuban, and Orinoco—the addition of these two crocodile species discovered on Cozumel and the atoll Banco Chinchorro brings that number up to six. The details of these new species can be found in a new article published in the journal Molecular Phylogenetics and Evolution.

“Biodiversity is disappearing faster than we can discover what we’re losing,” McGill biologist Hans Larsson, the senior author of the study, said in a press statement. “Most species of crocodiles are already endangered, and rapid shoreline development threatens nearly every population. Our research aimed to uncover the true diversity of crocodiles on these isolated islands.”

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One of the oldest-living species of reptile on Earth—sharing (along with birds) some of its genetic lineage with the long-extinct dinosaur—crocodiles migrated to the Americas roughly seven million years ago during the tail end of the Miocene epoch. It’s likely that a descendent of New World crocodiles, Crocodylus checchiai, traversed the Atlantic aided in part by westward ocean currents. Although well-known for its perplexingly slow rate of evolution, the crocodile eventually diversified into the four—now six—species we know today in the Americas.

The discovery of these new crocs was completely unexpected, according to the study’s lead author José Avila-Cervantes. Avila-Cervantes and his team compared the genetic sequences of the crocodile populations found on Cozumel and Banco Chinchorro to other known populations of New World crocodiles, and found enough genetic differentiation to necessitate a new species distinction—not just a variant of the American crocodile, the most widespread of the New World crocodiles. Scientific names have yet to be assigned to these new species, though a hat-tip to their respective island habitats seems like a good bet.

Although it’s always thrilling to discover a new species—especially one as large as these crocs—the study also adds a dash of concern. Although both populations are stable, they’re small, in both ecosystem size and breeding population. The study estimates that each species contain fewer than 1,000 breeding individuals.

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“Now that we recognize these crocodiles as distinct species, it’s crucial to protect their habitats,” Larsson said in a press statement. “Limiting land development and implementing careful conservation strategies on Cozumel and Banco Chinchorro will be key to ensuring their survival.”

That could prove difficult, as both islands are popular tourist destinations. Cozumel has already seen more than 1.5 million cruise ship tourists in the first three months of 2025, which puts a strain not only on endemic species like crocodiles, but on natural wonders like the island’s coral reef system. If the Cozumel and Banco Chinchorro crocodiles have any hope of survival, it’ll be because the people of those islands recognize their undeniable worth to the surrounding ecosystem—the natural resource that brings millions flocking to these islands in the first place.

Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough. 

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