Divers/Loons: skull

Skulls of Divers are of the schizognathous type and develop more or less in the same manner as in the Alcids. Ossification and fusion of the separate parts: maxillary and lachrymal bones, takes place in the periode between fledging and the next spring. Like the Alcids Divers develop a supraorbital ridge which increases in thicknes during the rest of the bird's life. A fragile and thin ridge is present in the second winter.