And now, from prehistory to today.
From Wildlife Extra:
New discovery more than doubles known crocodile species
Study reveals how little is still known about crocodiles’ biogeography, proves invaluable to conservationists
December 2013: Research has revealed that there are more than twice as many species of African crocodile, perhaps the continent’s most iconic creature, as previously believed. A recent study by the University of Florida has now found there are at least seven distinct species of African crocodile – long thought of as just three known species.
The UF team’s latest discovery, led by then-doctoral candidate Matthew H. Shirley, is that what had been believed to be a single species of slender-snouted crocodile, is actually two.
The results emphasise how little is known about crocodile biogeography, or how species are distributed geographically over time, in Western and Central Africa, said Jim Austin, a co-author on the paper and Shirley’s doctoral adviser at UF.
In the paper, Shirley and his team describe that West African populations of the slender-snouted crocodile do not share the same genetic or specific physical features as those populations in Central Africa – and they estimate the two populations have been separated from each other geographically for at least 7 million years.
Biologists and conservation agencies need to know the precise taxonomy of animals and plants to avoid allocating precious conservation funding and effort working to protect species that may be more plentiful than believed, or – as in this case – ensuring that those resources can be directed toward species whose numbers are lower than estimated.
This video says about itself:
Male slender-snouted crocodile bellowing to a female. Later, they mated. Notice the very characteristic posture: tail raised, head oblique.
The Wildlife Extra article continues:
Now that researchers know the West African slender-snouted crocodile is not the same species as its Central African cousin, Shirley said, that changes its standing.
“The West African slender-snouted crocodile is actually among the three or four most endangered crocodiles in the world,” said Shirley. “By finally recognising that it is a unique species, we are in a much better position to advance its conservation and ensure its future.”
Crocodile species are often difficult to identify by physical characteristics alone. Most non-scientists can barely tell the difference between an alligator and a crocodile, in fact. The UF team looked at skull characteristics of slender-snouted crocodiles from museum collections and were able to find consistent differences between the species, Austin said.
See also here.
Slender-snouted crocodiles, Rotterdam zoo: here.
- Crocodiles, alligators use sticks to lure, capture prey (seattletimes.com)
- Clever crocodiles, alligators use sticks to lure prey (yakimaherald.com)
- Sunday Species Snapshot: Cuban Crocodile (blogs.scientificamerican.com)
- Crocodiles are Cleverer Than Previously Thought: University of Tennessee Study (medindia.net)