By looking at 90-year-old crocodile skulls in museum collections and cross-checking these with live specimens at a zoo in Florida, researchers have discovered a previously unknown species of ten-foot-long crocodile.
The new crocodile, described in the journal Copeia, is from the island of New Guinea. Small species are regularly discovered by scientists, but discoveries of this size are a much rarer occurrence.
A new croc species
Ever since the New Guinea Crocodile was officially described in 1928, researchers have wondered if the island might, in fact, be home to two separate species: one from the north and another from the south. This new study has found that this is, in fact, the case.
The study was started in 2014 by Chris Murray, Assistant Professor at Southeastern Louisiana University, and Caleb McMahan, a scientist at the Field Museum.
Taking the work of another scientist, University of Florida researcher Philip Hall as a reference, the two scientists set out to explore how an analysis of very small details can help to differentiate different species.
In order to discover the new species, Murray and McMahan examined 51 Crocodylus novaeguineae skulls. They analyzed differences between crocodiles that had lived in the northern and southern parts of the island.
"Chris does a lot of work on crocodilians, and I do a lot of evolutionary work, often with morphology, or the animals' physical features. Chris studies morphology too, so it was continuing along with a lot of the projects we were doing, but then lo and behold, it's this brand new crocodile species," McMahan, a senior author of the paper, said in a press release.
The 51 New Guinea croc specimens came from seven different museum collections: the Field Museum, Louisiana State University Museum of Natural Science, Florida Museum of Natural History, American Museum of Natural History, Museum of Comparative Zoology at Harvard University, Queensland Museum, and Smithsonian National Museum of Natural History.
After visiting these museums and comparing the skulls, the researchers visited the St. Augustine Alligator Farm Zoological Park in Florida.
"They have live individuals of what's called novaeguineae, and we were able to look at those and say, 'Oh yeah, this matches the north and this matches the south!' I thought that was super cool," says McMahan.
The northern and southern crocodiles are different enough that the two scientists were able to classify the southern crocs a separate species, the Crocodylus halli, named after Philip Hall, the late scientist whose work inspired Murray and McMahan.