''Dryornis'' (meaning "tree bird"), also called the Argentinian vulture, is an extinct genus of cathartid (New World vulture), known from Argentina. The genus contains two species, ''D. pampeanus'' and ''D. hatcheri''.

Discovery and naming

''Dryornis'' was first described in 1891 by Argentine paleontologists

Francisco Moreno Francisco Pascasio Moreno (May 31, 1852 – November 22, 1919) was a prominent explorer and academic in Argentina, where he is usually referred to as ''Perito'' Moreno (''perito'' means "specialist, expert"). Perito Moreno has been credited as on ...

and Alcides Mercerat, the type species being ''D. pampeanus,'' based on the distal portion of a right humerus and a right femur that was supposedly part of the same individual, though it has since been referred to the phorusrhacid '' Mesembriornis milneedwardsi.'' The fossils had been collected from the Pliocene age deposits of the Monte Hermoso Formation in Buenos Aires, Argentina and have since been deposited at the

Museo de La Plata The La Plata Museum ( es, Museo de la Plata) is a natural history museum in La Plata, Argentina. It is part of the (Natural Sciences School) of the UNLP (National University of La Plata). The building, long, today houses 3 million fossils an ...

under specimen number MLP 20-169. Between 1896 and 1899, the American

Princeton University Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...

dispatched several expeditions to the Miocene

Santa Cruz Formation The Santa Cruz Formation is a geological formation in the Magallanes/Austral Basin in southern Patagonia in Argentina and in adjacent areas of Chile. It dates to the late Early Miocene epoch, and is contemporaneous with eponymous Santacrucian ...

of Santa Cruz, Argentina to recover fossils of taxa previously described by paleontologists like Moreno, Mercerat, and

Florentino Ameghino Florentino Ameghino (born Giovanni Battista Fiorino Giuseppe Ameghino September 19, 1853 – August 6, 1911) was an Argentine naturalist, paleontologist, anthropologist and zoologist, whose fossil discoveries on the Argentine Pampas, especially ...

. These expeditions were led by notable fossil collector

John Bell Hatcher John Bell Hatcher (October 11, 1861 – July 3, 1904) was an American paleontologist and fossil hunter known as the "king of collectors" and best known for discovering ''Torosaurus'' and ''Triceratops'', two genera of dinosaurs described by O ...

, who in 1899, unearthed a fragmentary left humerus that was later referred to the “terror bird” ''

Phorusrhacos ''Phorusrhacos'' ( ) is an extinct genus of giant flightless terror birds that inhabited Argentina during the Miocene epoch. ''Phorusrhacos'' was one of the dominant land predators in South America at the time it existed. It is thought to have ...

'' in 1932.Sinclair, W. & Farr, M. 1932. Aves of the Santa Cruz beds. In: Scott, W. (ed.) Reports of the Princeton University expeditions to Patagonia (1896-1899). Princeton University. v.7, p.157-191. This humerus was deposited at the

Yale Peabody Museum The Peabody Museum of Natural History at Yale University is among the oldest, largest, and most prolific university List of natural history museums, natural history museums in the world. It was founded by the philanthropist George Peabody in 1866 ...

under catalogue number . It remained unstudied until 2022, when Argentine paleontologist Federico J. Degrange noticed its true affinities and described it as a new species of ''Dryornis, D. hatcheri.'' ''D. pampeanus'' was only known from the type specimen until a 2021 paper described an individual preserving a: right

pectoral girdle The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of ...

, articulated partial right forelimb, incomplete right

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

, and fragments from the

sternum The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sh ...

and

tibiotarsus The tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia. A similar structure also occurred in the Mesozoic Heterodontosauridae. These s ...

. The paper also assigned an isolated distal left ulna and another specimen preserving an incomplete right ulna and proximal right radius fragment. All of the fossils had been collected from the La Estafeta Beach in

Mar del Plata Mar del Plata is a city on the coast of the Atlantic Ocean, in Buenos Aires Province, Argentina. It is the seat of General Pueyrredón district. Mar del Plata is the second largest city in Buenos Aires Province. The name "Mar del Plata" is a s ...

Buenos Aires Buenos Aires ( or ; ), officially the Autonomous City of Buenos Aires ( es, link=no, Ciudad Autónoma de Buenos Aires), is the capital and primate city of Argentina. The city is located on the western shore of the Río de la Plata, on South ...

, Argentina and were from the

Late Pliocene Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

aged Chapadmalal Formation. The fossils allowed more detailed analysis of the species’ phylogeny and revealed many novel diagnostic characteristics for the species.

Description

''Dryornis'' represents the largest known cathartiform. Analysis of the known fossil materials suggests that it had a body mass of 26 kg, 57% greater than '' Vultur grypus'' (Andean condor) and 94% greater than '' Cathartes aura'' (turkey vulture). Several giant genera of extinct birds are known, with some birds like the pseudo toothed ''Pelagornis'' at 16-29 kg and the giant teratorn being the largest known bird at 70-80 kg. ''Dryornis'' is also distinguished from other cathartids in its skeletal anatomy. The sternum is much more pneumatized than that of other cathartids, likely an adaptation for its size and flight capabilities. ''Dryornis'' would have been a

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

, and the only such predator in its ecosystem.

Classification

In their phylogenetic analyses, Degrange ''et al''. (2021) recovered ''Dryornis'' as a member of the Cathartidae and

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to ''Coragyps''+''Cathartes''. It was more closely related to vultures then to condors.

References

{{Taxonbar, from=Q79639365 Cathartidae Prehistoric bird genera Santacrucian Piacenzian life Miocene birds of South America Pliocene birds of South America Fossil taxa described in 1891 Neogene Argentina Birds described in 1891