1. The pterosaur trackway is quadrupedal, with wide gauge.

2. In its overall look and style of quadrupedal movement, 'future predator' looked something like a giant flightless bat, and this is where I really got quite interested...

3. Despite the geographic separation of the families, the method of quadrupedal walking is similar: legs and arms held fairly straight, and bottom in the air.

4. It may have reared up on its hind legs to reach twigs and leaves, but would normally have been fully quadrupedal.

5. What is striking about human bipedal movement is that it is notably more economical than quadrupedal locomotion at walking rates.

6. In this new position, our innards were not as well supported as they had been in our quadrupedal ancestors.