Predentary

The Praedentale is an only bird Beck dinosaurs ( Ornithischia ) present additional bone in the lower jaw in front of the dentary.

It is an unpaired, often trowel -like bone, whose shape varies with the individual groups: the so Praedentale is at the Hadrosauridae broad and round, at the Ceratopsia narrow and pointed. It bears no teeth and is the functional counterpart of the small square of the upper jaw ( maxilla ) premaxillary bone ( premaxilla ). Together with this, it is typical of many bird Beck dinosaur beak-like snout, which was used to pluck the plant food (only for the ceratopsian forms of Rostralknochen the counterpart of the Praedentale. )

In addition to the characteristic twin- basin shape the Praedentale is one of the most prominent diagnostic features of the bird Beck dinosaurs.