Ancient penguins were giant animals for 30 million years, according to a newly-discovered fossil
The evolution of penguins is a bit of a puzzle for scientists. Did their ancestors fly or were they always confined to land and sea?
More importantly, were they always the size they are now?
Scientists from New Zealand and Senckenberg finally have some answers, thanks to their recent discovery of a fossil belonging to a giant, 150-centimetre long penguin. The fossil dates pack to the Paleocene era approximately 61 million years ago, making it one of the oldest penguin fossils in the world.
According to a new study which the scientists published in the journal The Science of Nature, these newly discovered bones differ significantly from other discoveries of the same age, which means early penguins were probably much more diverse than scientists previously thought. And their evolution likely began much earlier than previous research has suggested — maybe even as early as the dinosaur age, the scientists conclude.Where this fits in with what we knew about penguins
Some genetic analysis has shown that the Spheniscidae family, which present penguins belong to, evolved from flightless birds that lived 40-100 million years ago. Other scientists believe their earliest ancestors may have been birds that lived during the Cretaceous period 60-65 million years ago and were able to fly.
"What sets this fossil apart are the obvious differences compared to the previously known penguin remains from this period of geological history," said Dr Gerald Mayr, an ornithologist at Senckenberg Research Institute in Frankfurt and lead author of the study, in a statement. "The leg bones we examined show that during its lifetime, the newly described penguin was significantly larger than its already described relatives."
In other words, penguins reached a giant size quite early in their evolution. This size increase appears to have started soon after they became flightless, according to the paper, with giant species existing for at least 30 million years, from the mid-Paleocene to the late Oligocene period.
The penguin is almost as big as the largest-known penguin fossil which belonged to Anthropornis nordenskjoeldi. Nordenskjoeldi is thought to have lived in Antarctica about 45-33 million years ago, and reached enormous heights of 180 centimetres. For comparison, Emperor penguins are the tallest current living species of penguin, and they grow up to 122 centimetres.
See photos of the birds: