Back in 2002, a short paper came out that commented on the observation that captive caimans would eat fruit left in their cage. When I initially read the paper, I found it interesting. In the end, though, I assumed this to just be a fairly anomalous incident.
Now Darren Naish of Tet Zoo has followed up on this story with further evidence of frugivory in crocodylians.
As one can see, this observation has been filmed at least once.
So does this mean that crocodylians are not as completely carnivorous as once thought? It’s hard to say. All observations made so far have been from alligatorids (alligators and caimans). This might be an apomorphic trait to this group. Only more observations will say for sure.
Another option that Darren pointed out, is that this was a learned trait of these captive animals. In each case, observed animals were found to be sharing their enclosures with herbivorous animals (usually tortoises). This type of operant learning is rather rare, and would be amazing if found to be true.
However, as evidenced by the comments of St. Augustine Alligator Farm park director, John Brueggen, fruit eating has been observed in wild animals too; so this is not simply a case of bored captives.
Whatever the case, these observations do illustrate just how adaptaptable crocodylians are as a group.