Don’t Try this Goose for Christmas
A paper detailing the research done on a skull of a giant ancestor of geese and ducks has just been published in the scientific journal “Palaeontology”. The skull represents a genus of large sea-going bird that had a lifestyle similar to the wandering albatrosses of today, but it was much bigger, soaring over what was to become Kent, Essex and London approximately 50 million years ago.
The giant goose-like bird is estimated to have had a wingspan in excess of 5 metres, much larger than any bird today, but not quite matching the South American Argentavis magnificens – a giant, condor-like creature from the Neogene. However, this giant ancestor of modern geese, scientific name Darsornis emuinus but affectionately called “Mother Goose” by the German researchers studying the fossil did have a beak full of tooth-like projections indicating that like Argentavis this bird also was a carnivore.
A fossil skull was discovered on the Isle of Sheppey, a small island off the northern coast of Kent in the Thames estuary. During the early Cenozoic, much of Europe was far warmer than it is today and southern England was bordered by a warm, shallow tropical sea. Fossils of crocodiles, turtles, ancient mammals and many birds have been found, but not many are as spectacular as this fossil skull belonging to a bird the size of a small plane.
The fossil remains of this incredible bird were studied by a joint team of scientists from the Senckenberg Research Institute and the Natural History museum in Frankfurt. Darsornis is thought to have had a similar lifestyle to the albatross of today, which spends most of its life at sea and is a master at using thermals and air currents to remain airborne with minimum effort. The huge wings would have helped Darsornis glide effortlessly above the tops of waves looking for squid or fish at the surface. The beak with its sharp projections could then be used to grab these slippery animals plucking them from the water. The teeth-like structures would have prevented the prey from escaping. A similar lifestyle and feeding habit has been suggested for the giant pterosaur Pteranodon, but this reptile never evolved teeth to help it grab prey, its ancestors had teeth but this large flying reptile lost them.
Like Pteranodon, Darsornis had other adaptations to help it fly:
Dr Meyr, a spokesperson for the research team commented: “They had lightweight bones so despite their great size they were not very heavy. I think they were capable of soaring and gliding – though they would probably have needed strong winds to take off. By today’s standards these were pretty bizarre animals, but perhaps the strangest thing about them is that they had sharp, tooth-like projections along the cutting edges of the beak”.
The scientists have described the 25cm long beak of this bird as resembling a crocodile’s jaw.
Some early birds had enamel teeth but these were lost about 100 million years ago, yet birds like Darsornis developed them again, this time made from bone and possibly covered with a layer of keratin, the biological material used for the beak. Dr Meyr believes that the 60 to 80 teeth in the beak, were developed to help the prehistoric bird keep a grip of the fish and squid it would have snatched from the sea.
“No living birds have true teeth – which are made of enamel and dentine – because their distant ancestors did away with them more than 100 million years ago, probably to save weight and make flying easier,” the doctor commented.
When the bird died it sank to the bottom of the sea, perhaps, getting stuck in the water and being so big it would have found it difficult to take off again without favourable winds. It was preserved after becoming covered in sediment. It was discovered about five years ago by a private collector but has only now been fully analysed. Although the bird had a similar lifestyle to the albatross, analysis of its remains has shown that its closest relatives, living or extinct, are ducks and geese.