A rare skull of a huge extinct thunderbird has been discovered in Australia

(CNN) — For more than a century, scientists have been searching in vain for the fossil skulls of the thunderbird species Genyornis newtoni. About 50,000 years ago, these giants, also known as miherong, an Aboriginal term meaning “giant bird,” strode across the forests and grasslands of Australia on muscular legs. They were taller than humans and weighed hundreds of kilograms.

The last Mahirong became extinct about 45,000 years ago. The only skull found in 1913 was incomplete and badly damaged, raising questions about the giant bird’s face, habits and lineage.

Now, the discovery of a complete G. Newtoni skull has solved this long-standing mystery, giving scientists their first face-to-face encounter with the enormous mihirung.

And he has a very strange goose face.

Shown here is the skull of G. Newtoni, helping to solve a long-standing mystery about the giant bird’s face. (Credit: Flinders University)

G. Newtoni was about 2 meters long and weighed up to 240 kg. It belonged to the family Dromornithidae, a group of flightless birds known from fossils found in Australia.

Between 2013 and 2019, a team of paleontologists unearthed a fossil of G. newtoni in Lake Kalapuna, South Australia, and discovered multiple skull fragments, a skeleton, and an articulated skull that provided the first evidence of the bird’s upper beak. This wealth has shed new light not only on G. newtoni, but also on the entire group of dromornithids, linking it to modern waterfowl such as ducks, swans and geese, the scientists reported Monday in the journal. Historical biology.

Although scientists have known about Geniornis for more than a century, new fossils and reconstructions provide important missing details, he said. Larry Whitmerprofessor of anatomy and paleontology at Ohio University, who was not involved in the research.

“The skull is always the prize, simply because there is so much important information in the head,” Whitmer said in an email. “It’s where the brain and sense organs are, it’s where the feeding system is, and it’s usually where the display organs (horns, combs, wattles, combs, etc.) are located,” he said. “In addition, skulls tend to be full of skeletal features that give us clues about their lineage.”

In the new study, “the authors extracted everything from these new fossils,” Whitmer said. The researchers not only modeled the skull bones, but also analyzed the location of jaw muscles, ligaments and other soft tissues that indicate the bird’s biology.

“This recent discovery of new Geniornis skulls has really helped fill in the blanks,” Whitmer said.

“Very goose-like.”

The newly discovered skull takes center stage in the digital reconstruction, complemented by other skull fossils and data from modern birds, and provides previously unknown clues about the appearance of G. Newtoni, said the study’s lead author. Phoebe McInerneya vertebrate paleontologist and researcher at Flinders University in South Australia.

“Only now, 128 years after its discovery, can we say what it really looked like,” McInerney said in an email. “Genernis has a very unusual beak that closely resembles that of a goose.”

Compared to the skulls of most other birds, the skull of G. Newtoni is very short. But the jaws are huge and supported by strong muscles.

“They had a very spacious space,” McInerney said.

The skull also alluded to the diet of G. Newtoni. The flat grasping area on the beak was suitable for tearing apart soft fruits, buds and tender leaves, and the flat palate on the underside of the upper beak was probably used to crush fruits into pulp.

“We knew from other tests that they probably ate soft foods, and the new spike supports that,” McInerney said. “The skull also showed some evidence of adaptation to feeding in water, perhaps to freshwater plants.”

This suggestion of underwater feeding is unexpected, given the enormous size of G. newtoni, Whitmer said.

“Maybe this shouldn’t be too surprising given that dromornithids like Genyornis belong to the group that includes ducks and geese, but Genyornis was 1.8 or 2.1 meters long, and probably weighed up to 226 kilograms,” Witmer said. Additional fossil discoveries could help resolve whether these adaptations are unused characteristics inherited from aquatic ancestors, “or whether these giant birds ventured into shallow waters in search of soft plants and leaves.”

“strange fusion”

The reconstruction helped scientists resolve the conflicting phylogeny of dromornithids and place them within the waterbird order Anseriformes, the study authors reported. Based on their associated skeletons and muscles, dromornithids may have been close ancestors of modern South American wobabirds, duck-like birds that inhabited the wetlands of southern South America.

Scientists suggest placing Genyornis newtoni within the waterfowl clade. The infographic also highlights how the size of G. newtoni compares to its closest relatives, Anhima cornuta (closest to G. newtoni) and the cassowary (unrelated). (Credit: Phoebe McInerney)

While G. newtoni had a goose-like beak, its face didn’t exactly match that of a modern goose, said study co-author and bird paleontologist. Jacob Blokland. Blokland, a researcher in the Flinders Paleontology Collection at Flinders University, illustrated the skull and Newtonian reconstructions in life.

“I was surprised by how superficial the goose looked with its large beak, but it is certainly different from any goose we have today,” Blokland said in an email. “It has some aspects that are reminiscent of parrots, which are not very closely related to them, but it also reminds us of wild birds, which are much closer relatives. In some ways, it feels like a strange amalgamation of very different-looking birds.”

For the new reconstruction, Blokland started with the bony region of the outer ear, “because there are many specimens that have preserved that part,” he says. From there, he built a consistent scaffold across many skull fossils. Some areas of the reconstruction were based on skulls belonging to other dromornithids or modern waterbirds, and anatomical studies of modern birds have indicated how muscles and ligaments move the bones.

One previously unknown detail was a broad, triangular bony shield called a helmet on the top of the beak, which may have been used for sexual displays, the study authors reported.

Two of the study’s co-authors, Phoebe McInerney and Jacob Blokland, stand in front of the skull of Geniornis newtoni. (Credit: Flinders University)

McInerney said large, flightless emus and cassowaries (which are not close relatives of thunderbirds) currently roam Australia, but they cast much smaller shadows than the long-vanished hirongs, which still loom large in the popular imagination. He added that there is much about the anatomy of these extinct giants that remains to be discovered, such as how the inner ear structures associated with head stabilization and locomotion are affected by gigantism and the inability to fly.

Although the new perspective on G. newtoni is the most accurate yet, additional excavations will shed more clear light on the profile of this unusual giant goose (the last of the mighty thunderbirds) and its disappearing habitat, Blokland said.

“Such a giant and unique bird certainly impacted the environment and other animals it interacted with, both large and small,” he said. “Only through study can we build a broader picture and discover what we are missing now.”

— Mindy Weisberger is a science writer and media producer whose work has appeared in Live Science, Scientific American, and How It Works.