Like its fellow enantiornithines, and unlike modern birds, it does not appear to have a digestive organ called a gizzard, or gastric mill, that helped it crush up its food.

Grit: As chickens do not have teeth, they eat sand and small stones to fill their gizzards.

But it was Meat Rats — and several instances of selling misbranded chicken gizzards, pork spareribs and other meat — that put an end to Ya Feng, which ceased operations at the end of 2022.

Many species of birds purposefully consume small stones and grit, which collect in their gizzards – the second part of their stomachs – and help the birds digest their food by pulverizing it.

Before anything enters a bird's gizzard, an organ for grinding up food, the proventriculus secretes digestive enzymes and hydrochloric acid to break down meals.