While crocodiles may not look that fast while sunbathing on the banks of rivers, they can easily pick up speed when needed.
The gallop happens when an animal's front and hind limbs hit the ground at the same time, with the hind legs pushing it shortly after; meanwhile, a gallop is a sequence of four beats in which the front and hind limbs take turns landing.
It was previously believed that only the freshwater crocodiles of Australia (Crocodylus johnstoni ) were able to do that. But actually that's not true. Not really.
Setting up video cameras around a zoological park in Florida, veterinary scientists analyzed the movements and speeds of 42 individuals of 15 crocodile species, which includes true crocodiles (family Crocodylidae ) and alligators.
While alligators and caimans could only walk on land, the team noticed eight species of crocodiles that were able to gallop or bound.
A rampant crocodile. (Royal Veterinary College/PA)
This is the first study to properly document galloping in the Philippine crocodile (Crocodylus mindorensis) the Cuban crocodile (C. rhombifer) the American crocodile (C. acutus ), the slender-shelled crocodile (Mecistops cataphractus) and the dwarf crocodile (Osteolaemus tetraspis) .
Judging by how common this ability seems to be, it is likely that more species that can do the same. There have been anecdotal reports of galloping in species such as the swamp crocodile (C. palustris) and the New Guinea crocodile (C. novaeguineae ).
No matter their size, almost all of the species studied were capable of reaching nearly 18 kilometers per hour, either by trotting, galloping or stunting.
Only crocodiles, however, could use their legs asymmetrically, providing longer stride frequencies, especially among those with smaller body sizes. It is not known exactly why alligators cannot do the same.
An example of delimitation. (Royal Veterinary College/PA) Similar to other studies, researchers think the crocodile's unusual asymmetrical movement came from a long-lost ancestor that lived on land and had longer legs.
If this is correct, it could mean that the ancestors of crocodiles somehow lost this ability or no longer express it.
But there is also another possibility that is rarely acknowledged: the common ancestor of today's 20 crocodile species may have actually evolved this asymmetrical gait rather than inheriting it.
Looking at related species could clear up some of the confusion - the gharial is a fish-eating Asian crocodile that lies outside the ancestry Crocodyloidea and Alligatoroidea, so if it can be shown that they have asymmetrical gaits, it could shed light on how this ability appeared.
But similar to crocodiles and alligators, the gharial's movements are not well documented, so there is clearly a lot more research that needs to be done.
SOURCE / Science Alert
