Phorusrhacos

Phorusrhacos
Temporal range: Early - Mid Miocene, 20–13 Ma
Reconstructed skull, Natural History Museum, Karlsruhe
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Cariamiformes
Family: Phorusrhacidae
Subfamily: Phorusrhacinae
Genus: Phorusrhacos
Ameghino, 1887
Type species
Phorusrhacos longissimus
Ameghino, 1887
Synonyms
Genus synonymy
  • Callornis Ameghino, 1895
  • Darwinornis Moreno & Mercerat, 1891
  • Eucallornis Ameghino, 1901
  • Liornis Ameghino, 1895
  • Owenornis Moreno & Mercerat, 1891
  • Phororhacos Ameghino, 1889
  • Stereornis Moreno & Mercerat, 1891
  • Titanornis Mercerat, 1893
Species synonymy
  • Callornis giganteus Ameghino, 1895
  • Darwinornis copei Moreno & Mercerat, 1891
  • Darwinornis socialis Moreno & Mercerat, 1891
  • Darwinornis zittelli Moreno & Mercerat, 1891
  • Eucallornis giganteus Ameghino, 1901
  • Liornis floweri Ameghino, 1895
  • Liornis minor Dolgopol de Saez, 1927
  • Mesembriornis quatrefragesi Moreno & Mercerat, 1891
  • Mesembriornis studeri Moreno & Mercerat, 1891
  • Owenornis affinis Moreno & Mercerat, 1891
  • Owenornis lydekkeri Moreno & Mercerat, 1891
  • Phororhacos longissimus Ameghino 1889
  • Phororhacos platygnathus Ameghino 1891
  • Phororhacos sehuensis Ameghino, 1891
  • Phororhacos shenensis Ameghino, 1891
  • Stereornis gaundryi Moreno & Mercerat, 1891
  • Stereornis rollieri Moreno & Mercerat, 1891
  • Titanornis mirabilis Mercerat, 1893

Phorusrhacos (/ˌfɔːrəsˈrɑːkɒs/ FOR-əs-RAH-koss) is an extinct genus of giant flightless terror birds that inhabited South America during the Miocene epoch. Phorusrhacos was one of the dominant land predators in South America at the time it existed.[1] It is thought to have lived in woodlands and grasslands.

Discovery and naming

[edit]
Holotype mandible

Remains are known from several localities in the Santa Cruz Formation and Monte León Formation in Santa Cruz Province, of Argentina.[2] Among the bones found in the strata of the Santa Cruz Formations (now considered as mainly of mid-Miocene date) was the piece of a mandible which Florentino Ameghino discovered in early 1887 and the same year at first described as that of an edentate mammal which he named Phorusrhacos longissimus.

The generic name is derived from Greek -φόρος, (-phoros), an element meaning "bearer" in word combinations, and ῥάκος, (rhakos), "rag" or "wrinkle", probably in reference to the wrinkled jaw surface.[3] When the original derivation was no longer understood, other translations were given, such as the literal translation of "Rag-Thief",[4] and "branch-holder" from the mistaken assumption the name had been intended to be derived from a Greek rhakis, "branch".[5] The specific name means "very long" in Latin, again in reference to the lower jaws. The holotype is the mandible, specimen MLP-118 (Museo de La Plata). In 1889 Ameghino emended the name to a more grammatically correct Phororhacos but the earlier name has priority. In 1891, it was by him recognized to be a bird.[6]

Description

[edit]
Life restoration

Phorusrhacos had a skull nearly 65 centimetres (26 in) long, stood nearly 2.4 meters (7 ft 10 in) tall, and probably weighed nearly 130 kilograms (290 lb), as much as a male ostrich.[7][8] It had very strong legs, capable of running at high speed, stubby, flightless wings, a long neck, and a proportionately large head. This ended in a huge, hooked beak that could tear through flesh easily, or stab into prey. The lower jaw was smaller than the upper jaw. There were three toes on each of the feet, all of which were armed with sharp claws.[1]

Classification

[edit]
Fossil skull
Life restoration by Charles R. Knight, 1901

Phorusrhacos was part of the group called the Phorusrhacidae, which is an extinct group of flightless, cursorial carnivorous birds that occupied one of the dominant, large land-predator niches in South America from the lower Eocene to the Pleistocene. They dispersed into North America during the Great American Biotic Interchange (~3 Ma). Some remains from Africa and Europe and the Paleocene of Brazil have been referred to this clade or identified as phylogenetically related to the extant South American seriemas, but these assignments remain controversial.[9]

The following cladogram follows the analysis of Degrange and colleagues, 2015:[10]

Phorusrhacidae 

References

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  1. ^ a b Richardson, Hazel (2003). Dinosaurs and Prehistoric Life. London: Dorling Kindersley Limited. p. 183. ISBN 0-7513-3734-X.
  2. ^ "Phorusrhacos". Fossilworks. Retrieved 17 December 2021.
  3. ^ Creisler, Ben. "Phorusrhacos "wrinkle bearer (jaw)": Etymology and Meaning". Dinosaur Mailing List.
  4. ^ "Phororhacos". Century Dictionary.
  5. ^ Lydekker, R. (1893). "On the extinct giant birds of Argentina". Ibis Series. 6 (5): 40–47.
  6. ^ Ameghino, F. (1891). "Mamíferos y aves fósiles argentinas. Especies nuevas, adiciones y correcciones". Revista Argentina de Historia Natural. 1: 240–259.
  7. ^ Croft, Darin A. (2016). Horned Armadillos and Rafting Monkeys: The Fascinating Fossil Mammals of South America. Indiana University Press. p. 120. ISBN 978-0253020840. Retrieved 30 March 2020.
  8. ^ Alvarenga, Herculano M. F. & Höfling, Elizabeth (2003). "Systematic revision of the Phorusrhacidae (Aves: Ralliformes)". Papéis Avulsos de Zoologia. 43 (4): 55–91. doi:10.1590/S0031-10492003000400001.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  9. ^ Federico J. Degrange, Drew Eddy, Pablo Puerta, & Julia Clarke (2019). "New skull remains of Phorusrhacos longissimus (Aves, Cariamiformes) from the Pleistocene of Argentina: implications for the morphology of Phorusrhacidae". Journal of Paleontology. 93 (6): 1221–1233. Bibcode:2019JPal...93.1221D. doi:10.1017/jpa.2019.53. S2CID 199094122. Retrieved 30 March 2020.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  10. ^ Degrange, Federico J.; Tambussi, Claudia P.; Taglioretti, Matías L.; Dondas, Alejandro; Scaglia, Fernando (2015). "A new Mesembriornithinae (Aves, Phorusrhacidae) provides new insights into the phylogeny and sensory capabilities of terror birds". Journal of Vertebrate Paleontology. 35 (2): e912656. Bibcode:2015JVPal..35E2656D. doi:10.1080/02724634.2014.912656. hdl:11336/38650. S2CID 85212917.