The largest flying predatory bird ever recorded was Argentavis magnificens, an extinct species that lived in South America during the Late Miocene, about 6 million years ago. Argentavis had an estimated wingspan of over 7 meters (23 feet), making it the largest flying bird known to have existed.
Key Facts About Argentavis magnificens
- Lived during the Late Miocene epoch, about 6-8 million years ago
- Inhabited open grasslands in central and northwestern Argentina
- Weighed 70-72 kg (154-159 lbs) with an estimated wingspan of 7-8 meters (23-26 ft)
- One of the largest flying birds ever to exist, rivaling the wingspan of a small airplane
- Part of the extinct family Teratornithidae, a group of massive predatory birds
- Scavenged carcasses and likely hunted small primitive horses, rodents, and other animals
Discovery and Naming
Argentavis magnificens was first described in 1980 by Argentine paleontologists Florentino Ameghino and Federico Pascual Ameghino. They named the new species Phorusrhacos magnificens, classifying it within the large predatory bird genus Phorusrhacos.
In 1984, American paleontologist Kenneth E. Campbell Jr. re-classified the species in a new genus Argentavis (“Argentine bird”). Further studies solidified Argentavis magnificens as a distinct species within the extinct family Teratornithidae.
The fossils of Argentavis were discovered in northwestern Argentina in deposits dating to the Huayquerian age of the Late Miocene. Partial wing bones were unearthed that allowed paleontologists to extrapolate the massive wingspan of this giant bird.
Size and Characteristics
Argentavis magnificens was among the largest flying birds ever known, exceeded in wingspan only by a few pterosaurs (extinct flying reptiles).
Key size characteristics:
- Wingspan estimates range from 6.1 m to over 8 m (20 – 26 ft)
- Weighed approximately 70-72 kg (154-159 lbs)
- Standing height over 5 feet (1.5 m) tall
- Wing surface area approximately 9 sq m (96 sq ft)
Argentavis had long, broad wings suited for soaring. Its legs were relatively short but strong, with large feet equipped with sharp talons. Studies of its hind limbs estimate Argentavis had a running speed of 10.1 m/s.
The skull was large with a long, hooked beak tipped with a sharp hook used for tearing flesh. Its eyes faced forward, providing binocular vision to spot potential prey.
Diet and Hunting
Argentavis magnificens is believed to have been an opportunistic predator and scavenger. Analysis of its size and morphology suggests that it primarily scavenged carcasses, using its huge wingspan to scan the landscape for dead animals from high aloft.
It likely also hunted live prey, using its talons to snatch small animals such as rodents, snakes, and fish. Argentavis may have occasionally attacked larger prey such as juvenile deer, pigs, or horses. It could have used its massive beak to stab and kill prey.
One 2010 study concluded that Argentavis needed to consume about 7 kg of food daily, and may have had to eat about 40% of its body mass every week. This high caloric requirement would mean it needed large prey items in order to survive.
Prey Animals
Some prey animals that lived at the same time as Argentavis included:
- Protohippus – An early horse species that weighed up to 100 kg
- Toxodon – A 2.5 meter long mammal that weighed up to 1,000 kg
- Macrauchenia – A llama-like mammal reaching heights over 2 meters
- Rodents like Josephoartigasia and Telicomys
- Snakes, lizards, and large flightless birds
These primitive mammalian megaherbivores and giant rodents provided nutrition sources for Argentavis. It likely flew in wide circles searching for dead or ill animals to feed on.
Flight Capabilities
The wings of Argentavis were well-adapted for dynamic soaring. It had relatively high aspect ratio wings ideal for efficiently riding air currents. Researchers estimate it had a gliding speed of 67 kph.
Some key flight adaptations:
- Long, slender wings designed for soaring flight
- Stiff wing bones reinforced to withstand air pressure loads
- Aerodynamic wing profile to generate lift
- Low, forward-set wing allowing good visibility while hunting
- High body mass helping momentum in turns and dives
Argentavis spent much of its time aloft, riding thermals and scanning widely for potential carrion. It was likely an agile flyer capable of rapid swoops and turns when approaching prey.
Comparison of Wingspans
Here is a table comparing the estimated wingspans of Argentavis with other huge predatory birds and flying animals known to have existed:
Animal | Wingspan |
---|---|
Argentavis magnificens | 7 meters |
Pelagornis sandersi | 6.4 meters |
Quetzalcoatlus northropi | 10-11 meters |
Hatzegopteryx | 10-12 meters |
Andean Condor | 3 meters |
This puts into perspective just how gigantic Argentavis really was. Its wings dwarfed even today’s largest flying bird, the Andean Condor. Only a few pterosaurs exceeded Argentavis in size.
Habitat and Range
Fossil evidence shows that Argentavis magnificens inhabited grasslands dotted with lakes and rivers in central Argentina. This environment supported a diverse ecosystem during the Late Miocene.
Key details about its habitat:
- Lived on the semi-arid pampas grasslands of Argentina
- Shared its habitat with primitive horse, camel, and rodent species
- May have nested in tall cliffs near bodies of water
- Probably concentrated around lakes and wetlands
Argentavis’s range was limited to Argentina, where multiple fossils have been found. It lived after South America split from Antarctica, isolating it from other landmasses. Few predators occupied its aerial niche in South America.
Argentavis Site Map
This map shows the approximate range of Argentavis magnificens in Argentina during the Late Miocene:
Fossils have been located in reddish sediments along bodies of water in La Pampa and Chubut provinces.
Extinction
The extinction of Argentavis approximately 2-5 million years ago was likely caused by multiple factors:
- Climate changes led to loss of habitat
- New mammalian predators like big cats competed with it
- Prey animals decreased in diversity and abundance
- Fewer large carcasses available to scavenge
A cooling climate resulted in the southern Atlantic forests expanding and displacing Argentavis’s grassland habitat. In addition, predators like saber-toothed cats outcompeted it for prey. With fewer megaherbivores to hunt or scavenge from, Argentavis could not survive.
No other giant terrestrial predator filled its niche after it died out. The extinct terror birds were also declining during this time. Argentavis lived on for a few million years as South America’s dominant aerial predator before vanishing.
Other Extinct Teratorns
Argentavis was part of the wider teratornithidae family of massive predatory birds. Some close extinct relatives include:
- Aiolornis incredibilis – A later, smaller teratorn with a 5 meter wingspan
- Cathartornis gracilis – Slightly older, wingspan around 6 meters
- Geronotopornis ales – 6 meter wingspan, lived in California 30 million years ago
These teratorns died out across North and South America in the Pleistocene around 2.5 million years ago. Competition from mammals was likely a major extinction factor.
Conclusion
Argentavis magnificens was the largest flying predatory bird known to have lived, with a wingspan up to 7 meters. This massive relative of vultures and condors dominated the skies over Argentina during the Late Miocene, feeding on both live prey and carcasses.
Capable of dynamic soaring and scanning wide swaths of grasslands for food, Argentavis filled an aerial apex predator niche in South America for millions of years before going extinct. No other birds ever grew as large again.
The fossils of Argentavis provide insights into the diversity of gigantic predatory birds that evolved in South America long before species like condors and eagles arrived. They represent an important part of the evolutionary history of raptors and help illuminate factors that drive gigantism in the flying vertebrates.