(CNN)A unique species of crocodile lives in New Guinea, but in 1989, a researcher suspected that there may be more to the story on the tropical island.
Philip Hall, the University of Florida researcher investigating if the island's crocodiles belonged to two different species, died before he could finish his work.
Now, researchers have finished up the work that Hall began and their new study shows that he was right. Their study published Thursday in the journal Copeia.
The New Guinea Crocodile was discovered in 1928. But the large island north of Australia is divided by a mountain range, creating distinct habitats in the north and south. The researchers wondered how different the crocodiles might be in these environments.
In 2014, Chris Murray, assistant professor at Southeastern Louisiana University, and Caleb McMahan, a scientist at the Field Museum in Chicago, were at a conference discussing the differences in reptile skulls. They attended a talk that raised Hall's research and asked for help to finish the investigation distinguishing between the New Guinea crocodiles.