As a thought project, I wanted to make an alien species that eats without any use of the tongue, but I've run into the problem that it's almost impossible to swallow solids without choking without the manuverability/vacuum the tongue provides. However, I stubbornly believe a tongue is not needed to eat for a jawed vertebrate with the following restrictions:
The alien has a jaw configeration similar to most jawed vertebrates (think dogs, not snakes; the jaw is not split and cannot move independently to walk food down the esophagus like snakes do)
The alien has bifurcated lips that can move independently of eachother; imagine if you could move your upper and bottom lip as freely as your fingers, but they had a division down the middle where your cupid's bow is (providing more moving parts for extra dexterity)
The alien chews it's food minimally in the mouth, then it gets sent to the crop/gizzard for further pulverization, then back to the mouth until it is adequately chewed.
The alien CANNOT
Possess a secondary jaw (although a dexterous, prolapsing esophagus would be okay)
Have an open jaw matrix like invertebrates/insects with external manipulators
But the alien MAY
Seal off it's airway while eating or otherwise have an unintegrated airway to the esophagus (In other words the airway does not go anywhere near the mouth)
Have a wacky esophagus (such as being able to close, prolapse, or tighten in select areas and not others)
Or any other solution that isn't flat out having a tongue or defying any of the restrictions I've put in place.