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Birds with a 20-foot wingspan once patrolled Antarctica



The ancient tartan tarantula depicted by an artist with a distinct tooth-like beak was harassed by ancient albatross.  An ancient perch depicted by a painter with its prominent toothed beak was harassed by ancient albatross.
illustration: Brian Joe

A reanalysis of the two fossils discovered in the 1980s led to the discovery of the absolutely huge Antarctic seabird.

The modern wandering albatross has an impressive wingspan of 11.5 feet (3.5 meters). However, the wings of this newly described bird stretched almost 20 feet (6 meters), full of imagination. It is said that this super-large Bole bird (“bony-othed”) bird was searching for squid and fish in the Antarctic sky during the Eocene epoch between 50 million and 40 million years ago. the study Published in “Science Report” today.

This newly described bird was identified from two fossils: the foot bones and the middle of the lower jaw. These fossils were originally discovered by a research team at the University of California, Riverside, who discovered them on Seymour Island in Antarctica during two different expeditions. These specimens eventually entered the Paleontological Museum of the University of California at Berkeley and were quickly forgotten.

Five years ago, the co-author of this new study, paleontologist Peter Kloess of the University of California, Berkeley, was browsing the museum collections, hoping to find something interesting.

“I like to go to collections, just to find treasures there,” said Cross, who was still a graduate student at the University of California, Berkeley. release. “Some people call me a museum rat, and I honor it. I like to wander around and find things that people ignore.”

Cruise was with Ashley Poust of the Natural History Museum of San Diego and Thomas Stidham of the Chinese Academy of Sciences in Beijing and discovered that he had discovered something that was overlooked. Decided to study these two fossils carefully. As the authors conclude in their new paper, “These Antarctic fossils indicate an early evolution of giant size. [pelagornithids], They may represent not only the largest flying birds of the Eocene, but also some of the largest flying birds [flying] It has a wingspan of 16.4 to 19.7 feet (5 to 6 meters).

Indeed, these birds are comparable to other extinct giants, namely Pelagornis sandersi (Another pelagornithid) with a wingspan of 20 to 24 feet (6 to 7.3 meters), and Argentavis, ArgentinaIts wingspan is 23 feet (7 meters).

Of course, we are talking about birds that can fly. The flightless, extinct elephant bird weighed 1,100 pounds (500 kg). And I will ignore those pterosaurs (not birds), their jaws have dropped 33 feet (10 meters). The species described in this new study is important because it appeared in evolutionary history earlier than other bird giants (Sanders SportsFor example, it appeared between 25 million and 28 million years ago).

Pelagornithids are a group of successful bone-toothed birds that went extinct 2.5 million years ago after 60 million years of reign. The giant Pelagornithid described in this new study dates back at least 50 million years ago, which is important from an evolutionary perspective.

Chloes explained that the new fossil discoveries “showed that after the extinction of the dinosaurs, birds evolved relatively quickly to a truly huge scale and ruled the ocean for millions of years.” As a background, the Cretaceous-paleontological extinction event All non-avian dinosaurs were wiped out. This incident occurred 66 million years ago.

Five-inch fossil jawbone.

The five-inch part of the fossil jawbone.
image: Peter Kloess/University of California, Berkeley

Pelagornithids are called bone-toothed birds because of the protrusions or struts on their jaws.These are not real teeth because they are covered with keratin, which is what our nails are made of. Scientists call these protrusions “false teeth”, but in terms of function, there is nothing fake, because these sharp drill bits are used to catch squid and fish from the ocean.

Lower jaw About 40 million years old, there are still some dentures, but they are badly worn due to erosion. Kloess and colleagues think they are about 1 The inch (3 cm) when the bird is still alive. This jaw was once fixed to a larger bird skull, its size is 2 Feet (60 cm) long. Carefully measured the spacing and size of the struts, and compared them with other known Bole birds. The results showed that the bird is larger in size, making it one of the largest known members of the bone and tooth group. The spacing of the teeth also helps to distinguish the specimen from other legume specimens.

BAfter reviewing the notes left by the original researchers, the research team realized that the fossil foot bones (tartar (long bones of the lower leg)) were pulled from geological formations older than expected. This means that fossils have a history of 50 million years, and the initial assumption is 40 million years.

At that time Antarctica had Warming, around Ocean is Full of early penguins Ducks, ostriches and Petrel, and other birds. For more than ten million years, huge predatory diarrhea animals are still important members of this ecosystem. New research shows.

“In a lifestyle that may resemble albatross, the giant extinct Plagornithids (Plagornithids) have very long wings. They fly extensively in the ancient high seas. Before that, whales and seals had not become the main ones. Dolphins, in search of squid, fish and other seafood, are caught with beaks lined with sharp dentures.” Stidham explained in the UC Berkeley release. “Large birds are almost twice the size of albatross, and these bony-toothed birds are already powerful predators, and they have evolved to the top of their ecosystem.”

More fossil evidence will help strengthen the estimates provided in the new study.Nevertheless, the new paper provides Some charming The dinosaur extinction event that began in the ancestor mirror deeply reflects the life during the Eocene.


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