Now the exciting world of crocodile classification has just become twice as complicated. It used to be that it was easy to tell crocodiles from alligators. If you were in Africa it was a crocodile. Now it turns out that there are two types of crocodiles living in the nile. nice crocs and nasty crocs.
In the 1970s, the industry that was involved in tanning crocodile hides was looking for ones with fewer bony scutes. A man called Fuchs did an analysis of the scutes to identify stocks that have fewer of them. He proposed some of these subspecies but the crocodile researchers threw out his work and said this guy doesn’t know what he’s talking about.
That’s the earliest sign of a morphological difference. People had been looking and looking and they just couldn’t see these differences. There had been all this evidence throughout the years about some extreme differences but most of the anecdotes were about their behaviour. Crocodiles are generally very hard to tell apart from their exterior features.
What about their behaviour?
There was anecdotal evidence about the weird behaviour of this crocodile. Many people, from Herotodus to current researchers, have described a sort of Nile crocodile that behaved differently. From my reading of the earlier literature about the exploration of the Nile, there were some suggestions of a smaller crocodile hanging out in the estuaries while the large, aggressive ones that everyone was afraid of lived in the middle of the Nile. Matt Shirley and I have thought about analysing the fine-scale ecological differences between the two to see if you could tap into how they could have overlapped in the Nile for so long before the recent period. Did they use different habitats or have different prey?
Tara Shine found these crocs living in caves in Mauritania that initially appeared to be sluggish because they were hanging out at the hottest time of the year. But people could feed them and come up to them and they weren’t aggressive at all. And some of the local populations apparently consider these crocs sacred.
Nile crocodile is actually two species (and the Egyptians knew it) | Not Exactly Rocket Science | Discover Magazine.