Ancient geese have hard teeth like bones

The 50 million-year-old skull revealed that the giant bird with a 5-meter wingspan had ever flown over the seas that today become London, Essex and Kent. They are relatives of ducks and geese but have a rather strange trait compared to birds: their mines have bone-like hard teeth.

The new fossil discovered at Sheppey Island has given a new meaning to the phrase 'Mother Goose'. The discovery was published in Palaeontology on September 26. The fossil skull belongs to Dasornis, a bone-like hard-toothed bird, also known as pelagornithid, discovered at the clay layer beneath London, Essex and north Kent in southeast England.

The fossil of the bone-toothed bird in the sediment has long been known but this new fossil is one of the most complete skull fossils ever discovered. It also preserves the previously unknown anatomical features of a strange creature.

With a 5-meter wingspan, this giant bird is quite similar to the albatross. Seagulls have the largest wingspan of modern birds, but the wingspan of Dasornis is even larger than 1.5 meters. Despite similarities, the most recent study shows that Dasornis's closest relative and this fossil are ducks and geese.

The Dasornis emuinus goose flies over the waters covering the area that today becomes London, Kent and Essex (United Kingdom).(Photo: Natural History Museum and Senckenberg Research Institute)

Gerald Mayr, a researcher of paleontology and ornithology at the Senckenberg Research Institute (Germany) and author of the paper, said: 'Imagine a bird like a goose hovering over the sea and having a click. the size of a small plane. Compared to today, there have been many strange animals, but perhaps the strangest thing about these birds is that they have protrusions like teeth on the edge of the mine ' . Like all modern birds Dasornis has a mine made of keratin, the same material as our hair and nails, but it has that bone. 'Real teeth must be made of tooth enamel and dentin. No modern bird has real teeth probably because their ancestors removed real teeth from over 100 million years ago to reduce weight to make flying easier. But real-toothed birds like Dasornis are unique among other birds because they recreate the tooth-like structure by forming this solid nail layer. '

So why did Dasornis have real teeth? Mayr said: 'This is related to diet. They probably flew over the sea, grabbing fish and squid when flying. With a normal mine, it is very difficult to keep prey and with the teeth it will make the prey unable to slip away. '

Refer:
Mayr et al. A skull of the bony-toothed giant Dasornis (Aves: Pelagornithidae) from the Lower Eocene of the Isle of Sheppey. Palaeontology, 2008; 51 (5): 1107 DOI: 10.1111 / j.1475-4983.2008.00798.x