Bonus on Bird Beaks

It had been assumed that, having a mobile palate (upper jaw), was an innovation unique to 'modern birds'. This feature is not found in some current 'old bird' species, like the Ostrich. Having a mobile palate enables birds to independently move their upper and lower jaws. This makes their beak highly flexible and dextrous, facilitating preening, nest building and food finding. A recent study on a fossil of one of the last toothed birds, however, may have turned that assumption on its head (https://www.theguardian.com/science/2022/nov/30/ct-scans-toothed-bird-fossil-jaw-mobile-palate-avian-evolution). A Computor Tomography (CT) scan was carried out on a toothed fossil of Janavis finalidens, discovered in a Belgian quarry in the 1980s. The CT scan revealed that Janavis had a mobile palate. Having a mobile palate, consequently pre-dates the origin of modern birds. The mystery now, is why birds like the Ostrich, have apparently abandoned this useful feature. Perhaps being flightless and eating grasses play a role?