Fossil stays point out these birds had a wingspan of over 20 toes. Brian Choo, CC BY-NC-SA

Image Antarctica immediately and what involves thoughts? Giant ice floes bobbing within the Southern Ocean? Perhaps a distant outpost populated with scientists from all over the world? Or maybe colonies of penguins puttering amid huge open tracts of snow?

Fossils from Seymour Island, simply off the Antarctic Peninsula, are portray a really totally different image of what Antarctica regarded like 40 to 50 million years in the past – a time when the ecosystem was lusher and extra numerous. Fossils of frogs and vegetation corresponding to ferns and conifers point out Seymour Island was a lot hotter and fewer icy, whereas fossil stays from marsupials and distant kin of armadillos and anteaters trace on the earlier connections between Antarctica and different continents within the Southern Hemisphere.

There have been additionally birds. Penguins have been current then, as they’re now, however fossil kin of geese, falcons and albatrosses have additionally been present in Antarctica. My colleagues and I’ve just lately revealed an article revealing new details about the fossil group that might have dwarfed all the opposite birds on Seymour Island: the pelagornithids, or “bony-toothed” birds.

Giants of the sky

As their title suggests, these historical birds had sharp, bony spikes protruding from sawlike jaws. Resembling tooth, these spikes would have helped them catch squid or fish. We additionally studied one other exceptional characteristic of the pelagornithids – their imposing measurement.

The biggest flying chicken alive immediately is the wandering albatross, which has a wingspan that reaches 11 ½ toes. The Antarctic pelagornithids fossils we studied have a wingspan almost double that – about 21 toes throughout. When you tipped a two-story constructing on its facet, that’s about 20 toes.

Throughout Earth’s historical past, only a few teams of vertebrates have achieved powered flight – and solely two reached actually large sizes: birds and a gaggle of reptiles referred to as pterosaurs.

Full-size mannequin of a Quetzalcoatlus on show at JuraPark in Baltow, Poland.

Aneta Leszkiewicz/Wikimedia

Pterosaurs dominated the skies in the course of the Mesozoic Period (252 million to 66 million years in the past), the identical interval that dinosaurs roamed the planet, and so they reached hard-to-believe dimensions. Quetzalcoatlus stood 16 toes tall and had a colossal 33-foot wingspan.

Birds get their alternative

Birds originated whereas dinosaurs and pterosaurs have been nonetheless roaming the planet. However when an asteroid struck the Yucatan Peninsula 66 million years in the past, dinosaurs and pterosaurs each perished. Some choose birds survived, although. These survivors diversified into the 1000’s of chicken species alive immediately. Pelagornithids advanced within the interval proper after dinosaur and pterosaur extinction, when competitors for meals was lessened.

The earliest pelagornithid stays, recovered from 62-million-year-old sediments in New Zealand, have been in regards to the measurement of recent gulls. The primary large pelagornithids, those in our research, took flight over Antarctica about 10 million years later, in a interval referred to as the Eocene Epoch (56 million to 33.9 million years in the past). Along with these specimens, fossilized stays from different pelagornithids have been discovered on each continent.

Pelagornithids lasted for about 60 million years earlier than going extinct simply earlier than the Pleistocene Epoch (2.5 million to 11,700 years in the past). Nobody is aware of precisely why, although, as a result of few fossil data have been recovered from the interval on the finish of their reign. Some paleontologists cite local weather change as a potential issue.

Piecing it collectively

The fossils we studied are fragments of complete bones collected by paleontologists from the College of California at Riverside within the 1980s. In 2003, the specimens have been transferred to Berkeley, the place they now reside within the College of California Museum of Paleontology.

There isn’t sufficient materials from Antarctica to rebuild a complete skeleton, however by evaluating the fossil fragments with related components from extra full people, we have been capable of assess their measurement.

In life, the pelagornithid would have had quite a few ‘tooth,’ making it a formidable predator.

Peter Kloess, CC BY-NC-SA

We estimate the pelagornithid’s cranium would have been about 2 toes lengthy. A fraction of 1 chicken’s decrease jaw preserves a number of the “pseudoteeth” that might have every measured as much as an inch tall. The spacing of these “tooth” and different measurements of the jaw present this fragment got here from a person as large as, if not larger than, the biggest recognized pelagornithids.

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Additional proof of the scale of those Antarctic birds comes from a second pelagornithid fossil, from a distinct location on Seymour Island. A piece of a foot bone, referred to as a tarsometatarsus, is the biggest specimen recognized for your entire extinct group.

These pelagornithid fossil findings emphasize the significance of pure historical past collections. Profitable subject expeditions lead to a wealth of fabric introduced again to a museum or repository – however the time required to arrange, research and publish on fossils means these establishments sometimes maintain many extra specimens than they’ll show. Necessary discoveries might be made by amassing specimens on expeditions in distant places, little question. However equally vital discoveries might be made by merely processing the backlog of specimens already available.

Peter A. Kloess doesn’t work for, seek the advice of, personal shares in or obtain funding from any firm or group that might profit from this text, and has disclosed no related affiliations past their educational appointment.