Crocodile

When we slit the belly, out tumbled the carcass of a crocodile, which was exactly six feet long.  The reptile hadn't been in there long because only a few patches of its hide had been digested.  I imagine that the anaconda would not have fed again for weeks.  A six foot thick armored crocodile is a big meal.

Near Contamana, Eastern Peru, August, 1958.  This six foot crocodile tumbled out of the snake's belly when the skin was removed.  Patches of the hide are already digested.

The anaconda would have had an easy time capturing this large reptile.  It would have thrown a coil around it, then submerged it in the water.  The snake, of course, would  have its head out of the water.  After about 30 minutes the crocodile would have commenced to drown.  Perhaps it died sooner due to damage from the constricting coil.  To swallow the reptile, the snake would have dislocated its jaws and slowly used "throat" muscles to bring it fully into its stomach.