Phorusrhacos
| Phorusrhacos | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Reconstruction drawing of Phorusrhacos |
||||||||||||
| Temporal occurrence | ||||||||||||
| Miocene | ||||||||||||
| 15.9 to 11.6 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Phorusrhacos | ||||||||||||
| Ameghino , 1887 | ||||||||||||
Phorusrhacos is an extinct bird genus from the family of phorusrhacidae ( "terror birds"), which in the Miocene in South America lived. The only species is Phorusrhacos longissimus .
features
Phorusrhacos was one of the larger representatives of the terror birds, but was more graceful and not as bulky as other giant ratites, for example from the genera Devincenzia or Brontornis . The tarsometatarsus was long and slender (on one specimen 362 mm, reconstructed 370 mm), it reached about 70 percent of the length of the tibiotarsus , both had about the diameter of the recent ostrich (genus Struthio ), which suggests an agile runner leaves. Numerous bones of this species have been preserved, mostly as fragments, from many parts of the body, but they only allow a total reconstruction with reservations. Almost all of the finds date from the 19th century. The first find (the type specimen ) comprises most of a lower jaw without the anterior (rostrade) end. An almost complete skull was later found, but it disintegrated into small fragments when it was recovered. Overall, there are various other skull fragments, including remains of the upper beak with the tip of the beak, and various sections of the foot and leg bones, including a femur and various finger bones (phalanges).
A body mass of around 93 kilograms to 130 kilograms was calculated for the species using various allometric calculation methods. In life reconstructions it reaches about the height of an adult human.
Research history
Phorusrhacos was the first of the South American terror birds to be discovered and scientifically described. However, after its discovery, the fossil was completely misunderstood and attributed to a mammal species. The type specimen of the species was discovered in 1887 by the Argentinian Carlos Ameghino in the Santa Cruz Formation , which was already famous for its wealth of fossils, and was discovered as a fossil mammal by his brother and closest collaborator Florentino Ameghino , at that time still sub-director and secretary of the La Plata Museum ( Edentata incertae sedis). Florentino Ameghino later changed the name to Phororrhacos , which was later viewed as an unjustified younger emendation and discarded. Soon after the find, the Ameghinos fell out with their boss at the time, the director of the museum Francisco Pascasio Moreno, and left the museum, but remained active as paleontologists, living off the sale of fossils and private funds from running a kiosk. A bitter enmity and personal feud soon developed between Ameghino and Moreno, similar to the more famous Bone Wars between (contemporary) North American explorers Othniel Charles Marsh and Edward Drinker Cope. As with these, the feud led to a race for new discoveries and too often imprecise and hasty initial descriptions to forestall the rival. The Ameghinos kept parts of their finds from the museum, they later came to the Museo Argentino de Ciencias Naturales Bernardino Rivadavia , whose director Florentino Ameghino became.
Moreno, like the Ameghinos, continued his collecting activity. In 1888 he discovered numerous mammal bones on Monte Hermoso, new finds, which he recognized as the remains of extinct, gigantic birds that were equal in size to the Gastornis , already known from Europe at the time. He described his finds as Mesembriornis milneedwardsi (in honor of Alphonse Milne-Edwards ), a second species discovered a little later as Palaeociconia australis . Until 1889, expeditions he sent out discovered fossils of even larger birds on the Río Santa Cruz , which apparently exceeded the size of the recent ostrich. These discoveries did not remain hidden from the Ameghinos, who initially saw no connection with their find. But after Carlos discovered an almost complete skull of Phorusrhacos in 1891 , they realized that it must have been a gigantic bird as well. Florentino Ameghino published these changes without even mentioning Moreno and his findings, and later tried to make the first mention of the giant birds by manipulating his brother. The Ameghinos and Moreno, with his newly appointed sub-director, the Swiss Alcides Mercerat, have now published first descriptions of bird fossils in order to deprive their rivals of the fame of the first description. As early as 1891 Moreno and Mercerat brought out an extensive monograph, Catálogo de los pájaros fósiles de la República Argentina conservados en el Museo de La Plata , in which numerous species were rewritten, including the genera Stereornis , Darwinornis , Owenornis , all later by Ameghino Phorusrhacos synonymized. Ameghino countered with Enumeración de las aves fósiles de la República Argentina in the same year in which he denied the work of Moreno any scientific value. Since both parties soon had no access to new fossil material and turned to other interests - Mercerat gave up science entirely and sold his collection to London - the feud between the two came to an end around 1897.
Almost all Phorusrhacos finds were published either by Ameghino (1887, 1889, 1895) or by Moreno and Mercerat in 1891, under various synonymous names. A number of other species that were described in the genus are now placed in other genera. Significant finds of the species in the 20th century or later are not known.
Systematics and taxonomy
|
Internal systematics of the Phorusrhacidae according to Degrange et al. 2015
|
The species is classified in the family of terror birds (Phorusrhacidae), which are united with the Seriemas (Cariamidae) still found in South America in the taxon Cariamae. Therein it forms with the genera Devicenzia , kelenken and Titanis the subfamily Phorusrhacinae. This division, as one of five subfamilies, was set up in the modern form of Alvarenga and Höfling. Alvarenga and colleagues could not fully reproduce them in their cladistic analysis (because of some unresolved polytomies), but regard them as justified in their interpretation of the results. However, Delgrange and colleagues later put forward a different structure.
Paleoecology
For the Santa Cruz Formation , which produced the only finds of the genus and species, a location is being reconstructed for the Miocene at about today's latitude, and thus outside the tropics. Since the mountains of the Andes had not yet bulged, the region was open to the westerly winds and was probably more rainy than today. Due to the flora and fauna, a significantly warmer and more humid climate than today is being reconstructed. Since both species adapted to open grasslands and tree dwellers belonged to the fauna, a savannah or park landscape with interspersed swamps and wetlands appears likely. According to their physique, the terror birds were probably residents of an open, tree-poor or tree-free landscape.
Along with Phorusrhacos longissimus , four other species of terror birds were found in the same layers, Patagornis marshi , Psilopterus lemoinei and Psilopterus bachmanni . With body masses of, respectively, 26, 15 and 5 kilograms, these were considerably smaller than Phorusrhacos . Presumably the species adapted to prey of different sizes, against each eingenischt . A comparably rich fossil fauna is not known from any other deposit.
literature
- Herculano Alvarenga and Elizabeth Höfling: Systematic revision of the Phorusrhacidae (Aves: Ralliformes) . Papéis Avulsos de Zoologia, 43 (4): 55-91, Sao Paulo 2003. PDF
Individual evidence
- ↑ a b c Herculano Alvarenga and Elizabeth Höfling: Systematic revision of the Phorusrhacidae (Aves: Ralliformes) . Papéis Avulsos de Zoologia, 43 (4), 2003, pp. 55-91 PDF .
- ↑ a b Federico J. Degrange, Jorge I. Noriega, Juan I. Areta: Diversity and Paleobiology of the Santacrucian Birds. In: Sergio F. Vizcaíno, Richard F. Kay, M. Susana Bargo (Eds.): Early Miocene Paleobiology in Patagonia: High-Latitude Paleocommunities of the Santa Cruz Formation. Cambridge University Press, 2012, pp. 138-155 ISBN 978-0-521-19461-7 .
- ↑ Eric Buffetaut: Who discovered the Phorusrhacidae? An episode in the history of avian palaeontology. In: Ursula B. Göhlich, Andreas Kroh (Ed.): Paleornithological Research 2013. Proceedings of the 8th International Meeting of the Society of Avian Paleontology and Evolution. Verlag Naturhistorisches Museum Wien, 2013. pp. 122–132.
- ↑ a b Federico J. Degrange, Claudia P. Tambussi, Matías L. Taglioretti, Alejandro Dondas, Fernando Scaglia: A New Mesembriornithinae (Aves, Phorusrhacidae) Provides New Insights Into the Phylogeny and Sensory Capabilities of Terror Birds. Journal of Vertebrate Paleontology 35 (2), 2015 doi: 10.1080 / 02724634.2014.912656
- ^ Herculano Alvarenga, Luis Chiappe, Sara Bertelli: Phorusrhacids: the Terror Birds. In: Gareth Dyke and Gary Kaiser (Eds.): Living Dinosaurs: The Evolutionary History of Modern Birds. John Wiley & Sons, first edition 2011.
- ^ Richard F. Kay, Sergio F. Vizcaíno, M. Susana Bargo: A review of the paleoenvironment and paleoecology of the Miocene Santa Cruz Formation. In: Sergio F. Vizcaíno, Richard F. Kay, M. Susana Bargo (Eds.): Early Miocene Paleobiology in Patagonia: High-Latitude Paleocommunities of the Santa Cruz Formation. Cambridge University Press, 2012, pp. 331-365 ISBN 978-0-521-19461-7 .
- ↑ Federico J. Degrange, Jorge I. Noriega, Sergio F. Vizcaíno: Morphology of the forelimb of Psilopterus bachmanni (Aves, Cariamiformes) (Early Miocene of Patagonia). Paeläontologische Zeitschrift 89 (4), 2015, pp. 1087-1096. doi: 10.1007 / s12542-015-0269-1
