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Photograph of Matt ShirleyRead the legendThe new species, the Central African snout crocodile
(Mecistops leptorhynchus), is the first to have been described in detail for more than 80 years.Photography of Matt ShirleyL "animal study of Central Africa, with exceptionally smooth skin, also revealed that his cousin was in danger of disappearing.
Posted on October 24, 2018
It's not every day that you find a new species of crocodile. For the first time in more than 80 years, researchers have completely described and named a new species, the Central African snout, which is found in much of the continent, from Cameroon to Tanzania.
This species has been dubbed Mecistops leptorhynchus and has been characterized in a study published October 24 in the journal Zootaxa.
Up to now, the animal was considered to belong to the same species as its West African counterpart, Mecistops cataphractus, which will retain its original scientific name. The new designation sufficiently reduces the total population of West African species to be considered endangered. According to Matt Shirley, senior author of the study and a researcher at Florida International University, there are only about 500 left in the wild.
The slender fangs of Central Africa have a softer and smoother appearance than their West African cousins, who have larger and heavier scales and rougher skin. says Shirley. The recently described fang also lacks bony ridges on his skull found on his counterpart.
But the main differences lie in the genes – and these differences are significant. The paper shows that animal genetics diverged for the first time more than eight million years ago, while volcanoes were forming in and around present-day Cameroon. This volcanic activity has created insurmountable mountains that divide the reptile chain in two, cutting off the flow of genes, and the two populations have not traded genes since, says Shirley, a National Geographic explorer.
This isolation has allowed both species to diverge, and now the base pairs that make up some important genes differ by more than five percent, he says.
Scientists have of course described other new species of crocodiles in recent years. For example, a study by George Amato at the American Museum of Natural History showed that dwarf crocodiles are not one, but three species. Shirley, Amato and their colleagues have also discovered that there are actually two different species of Nile crocodiles.
But M. leptorhynchus is the first species since 1935 to follow the entire formal process of designation and designation, explains Shirley. This involved browsing dozens of samples from museums around the world with the help of colleagues from the University of Iowa and the University of Florida. Shirley himself has also done intensive fieldwork in 14 African countries and has contracted malaria more than a dozen times during the research, he said.
Their work was complicated by the fact that the "typical" specimens, which are the original animals of the museum used to formally identify a given species, were not found for M. cataphractus. It is the Nazis' fault: the specimens were destroyed when German planes bombed the London Museum of Natural History during the Second World War. The researchers therefore had to designate new ones.
The study is "a continuous and repeated story about the under-described diversity of African crocodiles," says Amato, director of conservation genomics at the Sackler Institute of Comparative Genomics, who was not involved in the writing of this document.
The study should help stimulate conservation work for both types of crocodiles, but especially for species from West Africa. Shirley and her colleagues are working with the governments of Cote d'Ivoire and Ghana as well as a number of NGOs to rear captive animals and release them to the wild. The most important effort takes place in a zoo in Ivory Coast, where more than 30 of the animals currently reside.
Habitat loss and poaching affect both species, although there are so few thin – mouthed crocodiles in West Africa, it is almost impossible to find them, explains Shirley, who has spent "months and years" searching for them. In the end, he took DNA samples from 15 to 20 only.
Work is more urgent than ever. "These are really in danger," said Shirley. [could] disappear at any time. "
© 1996-2018 National Geographic Society.
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