Patagornis

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Patagornis
Temporal range: Early-Mid Miocene (Santacrucian-Laventan)
~17.5–11.6  Ma
Patagornis marshi.png
Skull of BMNH-A516
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Cariamiformes
Family:† Phorusrhacidae
Subfamily:† Patagornithinae
Genus:† Patagornis
Moreno & Mercerat, 1891
Type species
Patagornis marshi
Moreno & Mercerat, 1891
Synonyms
  • Paleociconia cristataMoreno & Mercerart 1891
  • Tolmodus inflatusAmeghino 1891
  • Tomodus inflatusAmeghino 1891
  • Phororhacos inflatusAmeghino 1891
  • Phororhacos modicusAmeghino 1891
  • Morenomerceraria cristataLambrecht 1933

Patagornis is a genus of extinct flightless predatory birds of the family Phorusrhacidae. Known as "terror birds", these lived in what is now Argentina during the Early and Middle Miocene; the Santa Cruz Formation in Patagonia contains numerous specimens. [1] [2] Patagornis was an agile, medium sized Patagornithine and was likely a pursuit predator.

Contents

Etymology

The genus name means "bird from Patagonia" after the location the fossils were found in and the species name after prominent American paleontologist Othniel Charles Marsh, who had also named notable fossil birds but from the American West like Hesperornis and Ichthyornis . [3]

Recently, Federico Agnolin has promoted reusing Florentino Ameghino’s 1891 name Tolmodus inflatus because the name Patagornis marshi wasn’t used for over 100 years until a paper by Alvarenga & Höfling in 2003. [4] [5] This would make the name Patagornis marshi a nomen nudum and Tolmodus inflatus the valid name due to its frequent use. [5] Despite this, the use of the Patagornis marshi has had a great resurgence in use in recent years and the proper nomenclature hasn't been established by the ICZN. The generic name Tolmodus means "bold tooth" due to the misinterpretation of the holotype premaxilla as the tooth of a mammal, while the species name means "inflated" due to its large size. [6]

History and taxonomy

In 1891 during the "Argentine Bone Wars", a competition between Argentine paleontologists Francisco Moreno and Florentino Ameghino, the former and his colleague Alcides Mercerart described a new genus and species of phorusrhacid, Patagornis marshi, based on a mandibular symphysis that was missing the tip, though it was then thought to be a piece of the premaxilla. The fossil (MLP-143) was found alongside many other parts of a skeleton, likely from the same individual as the symphysis, including: 3 vertebrae and fragments of many others, parts of the hindlimbs, and ungues. [4] [7] [3] The specific locality where these fossils were found isn't known in detail, besides that they came from the upper middle Miocene strata of the Santa Cruz Formation of Santa Cruz, Argentina. In the same paper, Moreno and Mercerat named 2 more species of Patagornis, Patagornis lemoinei and Patagornis bachmanni, based on fossils found in the Monte León Formation, Argentina in lower Miocene strata. [3] [7] They also named Palaeociconia cristata based on 2 vertebrae and 2 ungues from Santa Cruz, believing that they were from a fossil stork related to Ciconia. [3] In 1933, biologist Karl Lambert placed P. cristata in its own genus, Morenomerceraria, but the genus name has since no use since. [8] Palaeociconia cristata has since been synonymized with Patagornis marshi. [4] [7] P. lemoinei and P. bachmanni are now species of Psilopterus. [4]

Moreno's rival, Ameghino, also unknowingly found or described many fossils of Patagornis marshi from the Miocene deposits in Santa Cruz, many of the fossils being collected by Ameghino's brother Carlos Ameghino. [9] [7] [4] In August 1891, Ameghino named Tolmodus inflatus based on a fragment of the right premaxilla that had been collected by Carlos in the same middle Miocene deposits in Santa Cruz. [10] [4] Ameghino originally considered the taxon an edentate mammal related to Phorusrhacos , but 2 months later in June he synonymized the two and realized that they were actually flightless carnivorous birds, a conclusion made earlier by Moreno. [10] Ameghino over several years amassed many Patagornis fossils, many of which were described in his 1895 monograph on Patagonian fossil birds. [11] The most complete skeleton (BMNH-A516) includes a complete skull and mandible, one of the first complete Phorusrhacid skulls known, and many limb elements as well as a complete pelvis. [12] Another synonym of Patagornis marshi was named by Ameghino in 1895, Phororhacos modicus, based on a humerus and tarsometatarsus from Santa Cruz [13] and another mistakenly assigned fossil was a premaxilla wrongfully assigned by Ameghino to the rhea Opisthodactylus . [4] Ameghino also believed that the fossils came from the Cretaceous and Eocene " Pyrotherium Beds", when they actually were of Miocene age. [11] [4] By the end of the "Argentine Bone Wars", many Patagornis fossils had been collected and majority reside in the Museo de la Plata or the Natural History Museum, London. [4]

Several fragmentary Patagornis specimens were also collected by American crews from Princeton University and the Field Museum of Natural History in Princeton, New Jersey and Chicago, Illinois respectively, although the fossils found by the former now reside at the American Museum of Natural History in New York. [14] [4] [15] The Museo de la Plata also collected a nearly complete Patagornis skeleton, including a skull, though it is poorly preserved. [4]

Description and paleobiology

Life restoration Patagornis marshiDB24.jpg
Life restoration

Patagornis was very similar to Andalgalornis, another member of the subfamily Patagornithinae, in size and weight, however Andalgalornis was slightly larger. The diameter of the leg bones was about 15% larger than in the living rhea. However, the back height was about the same at 90–100 cm. [16] [4] Estimates of the weight vary: 45 to 50 kg [16] [4] or only 23 kg. [17] The walking speed of birds is determined by the ratio of the two leg bones tibiotarsus and tarsometatarsus and by their strength. At Patagornis this ratio is almost 70%, meaning that the taxon was very agile, a trait common among the smaller Patagornithines. Research from 2005 therefore showed that the animal had a maximum speed of 50 km/h, about the same speed as the living rhea. The anterior margin of the fenestra antorbitalis of Patagornis is moderately sloped, while at Andrewsornis it is strongly sloping and at Andalgalornis only slightly sloping. [4] Alvarenga & Hofling describe the dorsal portion of the nostrils as "very conspicuous". [4] The symphysis mandibulae is slightly curved, with the apex of the beak end uncurved. [4]

On the best preserved Patagornis skeleton, BMNH-A516, the ulna preserved large quill knobs on the posterior end that suggest large wing feathers. [12] These feathers were theorized to have been used for assistance in running, as implied by its ecology and limb anatomy, or as a shield like on the extant Secretary bird. [12] The former theory is much more likely based on the anatomy of the quill knobs themselves and their presence in the related Llallawavis which has a similar agile anatomy. [18] [12] The ungual phalanges preserved in Patagornis and its distant relative Mesembriornis are large, curved, and thin laterally, likely being used to stab prey based on those of modern predatory birds. [16]

Ear anatomy

In 2015 during their study on the ear anatomy of phorusrhacids, Degrange et al also studied the internal ear anatomy preserved in Llallawavis, Patagornis, & several modern birds. [18] They discovered that the hearing of Patagornis was very poor & had the smallest hearing range in the Cariamiformes studied. [18] The semicircular canals of Llallawavis were much more elongated compared to the short canals of Patagornis, and with the greater body mass, it was inferred that there were more sluggish head movements in this taxon, with enhanced sensitivity to low-amplitude motions. [19]

Classification

Due to the great preservation of Patagornis and its relatives, comparisons with other taxa and detailed classification are much easier compared to other phorusrhacids. In 2003 during their redescription of phorusrhacidae, Herculano Alvarenga and Elizabeth Hofling created a new subfamily, Patagornithinae, with Patagornis as the type genus. Patagornis is similar to its relatives Andrewsornis and Andalgalornis in that they all are medium-sized phorusrhacids with slender, lightly built bodies, long and narrow mandibular symphyses, and long and slender tibiotarsi and tarsometatarsi. However, a phylogenetic analysis in 2015 by Degrange et al found Patagornis in a merged Phorusrhacinae and in polytomy with Physornis and Phorusrhacos as well. [18]

The following phylogenetic tree shows the internal relationships of Phorusrhacidae under the exclusion of Brontornis as published by Degrange and colleagues in 2015, which recovers Patagornis as a member of a large clade that includes Physornis, Phorusrhacos and Andalgalornis, among others. [20]

Cariamiformes

Paleoenvironment

Patagornis lived during the middle Miocene in the Santa Cruz Formation, which preserves mostly a coastal environment, but also forested and grassland regions. [21] The area had little rainfall, so forests developed around lakes and rivers, giving Santa Cruz a diverse environment. [21] During the Miocene, the climate was similar to those of the coasts of Chile with semi-temperate forests and oceanic winds. [21] Grasslands began spreading into Argentina during the Miocene, though much of inner Patagonia was still arid with small rainforests in between. [22] Large, herbivorous, South American notoungulate mammals like the Toxodonts Nesodon and Adinotherium were the large low browsers, with rabbit-like Interathere Protypotherium being frugivorous. [22] Both mammalian and avian carnivores inhabited the area, the largest being the Phorusrhacid Phorusrhacos. Marsupials also lived in the region, including the large carnivorous Sparassodont Borhyaena. [21] Patagornis is also known from the coastal Monte Leon Formation that was in the same region in Santa Cruz, but part of the older lower Miocene age. [23] [24] Monte Leon preserved more mudstone and estuarine sediments, but with a very similar fauna to the Santa Cruz Formation as the two formations had a direct transition. [23]

Related Research Articles

<span class="mw-page-title-main">Phorusrhacidae</span> Extinct family of flightless birds

Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from the Middle Eocene to the Late Pleistocene around 43 to 0.1 million years ago, though some specimens suggest that they were present since the Early Eocene.

<i>Phorusrhacos</i> Extinct genus of birds

Phorusrhacos 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. It is thought to have lived in woodlands and grasslands.

<i>Titanis</i> Genus of terror bird (Phorusrhacidae)

Titanis is a genus of phorusrhacid, an extinct family of large, predatory birds, in the order Cariamiformes that inhabited the United States during the Pliocene and earliest Pleistocene. The first fossils were unearthed by amateur archaeologists Benjamin Waller and Robert Allen from the Santa Fe River in Florida and were named Titanis walleri by ornithologist Pierce Brodkorb in 1963, the species name honoring Waller. The holotype material is fragmentary, consisting of only an incomplete right tarsometatarsus and phalanx, but comes from one of the largest phorusrhacid individuals known. In the years following the description, many more isolated elements have been unearthed from sites from other areas of Florida, Texas, and California. It was classified in the subfamily Phorusrhacinae, which includes some of the last and largest phorusrhacids like Devincenzia and Kelenken.

<i>Andalgalornis</i> Extinct genus of birds

Andalgalornis is a genus of flightless predatory birds of the extinct family Phorusrhacidae that lived in Argentina. The type and only species is A. steulleti.

<i>Brontornis</i> Extinct genus of birds

Brontornis is an extinct genus of giant bird that inhabited Argentina during the Early to Middle Miocene. Its taxonomic position is highly controversial, with authors alternatively considering it to be a cariamiform, typically a phorusrhacid or an anserimorph.

<i>Mesembriornis</i> Extinct genus of birds

Mesembriornis is a genus of intermediate-sized phorusrhacids that grew up to 1.5 metres (4.9 ft) in height. They represent a well-distinct lineage of terror birds, differing from the massive large groups and the smaller Psilopterinae. In general proportions, they most resembled the Patagornithinae which flourished somewhat earlier, mainly to the south of the range of Mesembriornis. Fossils of the terror bird have been found in Montehermosan deposits of the Monte Hermoso Formation, as well as the Andalgala Formation and Chapadmalal Formation in Argentina.

<i>Paraphysornis</i> Extinct genus of birds

Paraphysornis is an extinct genus of giant flightless terror birds that inhabited Brazil during Late Oligocene or Early Miocene epochs. Although not the tallest phorusrhacid, Paraphysornis measured up to 1.4 metres tall at the hips and weighed around 180–240 kilograms (400–530 lb). It was also a notably robust bird, having short and robust tarsal bones not suited for pursuit hunting.

<i>Kelenken</i> Extinct genus of birds

Kelenken is a genus of phorusrhacid, an extinct group of large, predatory birds, which lived in what is now Argentina in the middle Miocene about 15 million years ago. The only known specimen was discovered by high school student Guillermo Aguirre-Zabala in Comallo, in the region of Patagonia, and was made the holotype of the new genus and species Kelenken guillermoi in 2007. The genus name references a spirit in Tehuelche mythology, and the specific name honors the discoverer. The holotype consists of one of the most complete skulls known of a large phorusrhacid, as well as a tarsometatarsus lower leg bone and a phalanx toe bone. The discovery of Kelenken clarified the anatomy of large phorusrhacids, as these were previously much less well known. The closest living relatives of the phorusrhacids are the seriemas. Kelenken was found to belong in the subfamily Phorusrhacinae, along with for example Devincenzia.

Physornis is an extinct genus of giant flightless predatory birds of the family Phorusrhacidae or "terror birds", most closely related to Paraphysornis, that lived in Argentina. The type species is P. fortis. It lived during the Middle to Late Oligocene (Deseadan). Few fossils are known, but the available material suggests that Physornis was one of the largest phorusrhacids.

<i>Devincenzia</i> Extinct genus of birds

Devincenzia is an extinct genus of giant flightless predatory birds in the family Phorusrhacidae or "terror birds" that lived during the Early Miocene (Deseadan) Fray Bentos Formation of Uruguay, Late Miocene (Huayquerian) Ituzaingó Formation, Early Pliocene (Montehermosan) of Argentina, and possibly the Early Pleistocene Raigón Formation of Uruguay. The type species D. pozzi was formerly known as Onactornis pozzi. The largest possible specimen weighed up to 350 kilograms (770 lb), making it one of the largest phorusrhacids and carnivorous birds known.

<i>Andrewsornis</i> Extinct genus of birds

Andrewsornis is an extinct genus of giant flightless predatory birds of the family Phorusrhacidae or "terror birds" that lived in Oligocene Argentina. Fossils have been found in the Sarmiento Formation, and possibly the Agua de la Piedra Formation.

<i>Procariama</i> Extinct genus of birds

Procariama is an extinct monotypic genus of phorusrhacid, which lived from the Late Miocene to the Late Pliocene of Argentina. Fossils of the animal have been found in six places, in the Cerro Azul and Andalhuala Formations. More specifically in the Andagalá department and in the north of the Belén department of the Catamarca province, with a single location in the La Pampa province. The type and only species, Procariama simplex, is the largest member of the subfamily Psilopterinae.

<i>Psilopterus</i> Extinct genus of birds

Psilopterus is an extinct genus of phorusrhacid from the Middle Oligocene to possibly the Late Pleistocene of Argentina and Uruguay. Compared to other phorusrhacids, members of the genus are both relatively gracile and diminutive, and include the smallest known species of terror bird: with the head raised P. bachmanni was 70–80 centimeters (2.3–2.6 ft) in height and weighed about 5 kilograms (11 lb), while the largest members of the genus were only about 8 kilograms (18 lb). The birds resemble the modern cariama, except with a heavier build and considerably smaller wings. Fossil finds in Uruguay indicate the genus may have survived until 96,040 ± 6,300 years ago, millions of years after the larger phorusrhacids became extinct.

Cunampaia is a dubious genus of extinct mesoeucrocodylian. Fossils have been found from the Divisadero Largo Formation of Mendoza Province, Argentina, and date back to the Divisaderan to Tinguirirican regional South American Land Mammal Age of the Late Eocene epoch.

<i>Llallawavis</i> Extinct genus of birds

Llallawavis scagliai is a large, extinct predatory bird from Pliocene Argentina. Its fossil is the most complete fossil of a phorusrhacid yet found.

The Agua de la Piedra Formation is a Late Oligocene geologic formation of the Malargüe Group that crops out in the southernmost Precordillera and northernmost Neuquén Basin in southern Mendoza Province, Argentina.

Dryornis, also called the Argentinian vulture, is an extinct genus of cathartid, known from Argentina. The genus contains two species, D. pampeanus and D. hatcheri.

Patagorhacos is an extinct genus of medium-sized phorusrhacid from the early Miocene of Patagonia. Currently only the single species Patagorhacos terrificus is known, which is represented by two highly fragmentary specimen, one belonging to the back of the skull and the other being the distal end of a leg bone. It was described together with the contemporary rheid Opisthodactylus horacioperezi.

Proadinotherium is an extinct genus of toxodontid. It lived between the Late Oligocene and the Early Miocene in what is now South America.

<span class="mw-page-title-main">Santa Cruz Formation</span> Geological formation in Patagonia

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 SALMA. The formation extends from the Andes to the Atlantic coast. In its coastal section it is divided into two members, the lower, fossil rich Estancia La Costa Member, which has a lithology predominantly consisting of tuffaceous deposits and fine grained sedimentary claystone and mudstone, and the upper fossil-poor Estancia La Angelina Member, which consists of sedimentary rock, primarily claystone, mudstone, and sandstone. The environment of deposition is interpreted to have been mostly fluvial, with the lowermost part of the Estancia La Costa Member being transitional between fluvial and marine conditions. The environment of the Estancia La Costa Member is thought to have been relatively warm and humid, but likely became somewhat cooler and drier towards the end of the sequence. The Santa Cruz Formation is known for its abundance of South American native ungulates, as well as an abundance of rodents, xenarthrans, and metatherians.

References

  1. ↑ Mayr, Gerald (2017). Avian Evolution: The Fossil Record of Birds and Its Paleobiological Significance. Chichester, UK: John Wiley and Sons. pp. 190–192. ISBN   978-1-119-02076-9.
  2. ↑ Patagornis at Fossilworks.org
  3. 1 2 3 4 Moreno, F. P., & Mercerat, A. (1891). Catálogo de los pájaros fósiles de la República Argentina conservados en el Museo de La Plata. Taller de Publicaciones del Museo.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 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 . ISSN   0031-1049.
  5. 1 2 Agnolin, F. (2013). La posición sistemática de Hermosiornis (Aves, Phororhacoidea) y sus implicancias filogenéticas. Revista del Museo Argentino de Ciencias Naturales nueva serie, 15(1), 39-60.
  6. ↑ Palmer, T. S. (1904). Index generum mammalium: a list of the genera and families of mammals (No. 23). US Government Printing Office.
  7. 1 2 3 4 Brodkorb, P. (1967). Catalogue of fossil birds: part 3 (Ralliformes, Ichthyornithiformes, Charadriiformes). University of Florida.
  8. ↑ Lambrecht, K. (1933). Handbuch der palaeornithologie.
  9. ↑ Buffetaut, E. R. I. C., Göhlich, U. B., & Kroh, A. (2013). Who discovered the Phorusrhacidae? An episode in the history of avian palaeontology. In Paleornithological Research 2013. Proceedings of the 8th International Meeting of the Society of Avian Paleontology and Evolution: Wien, Naturhistorisches Museum (pp. 123-133).
  10. 1 2 Ameghino, F. (1891). "Mamíferos y aves fósiles argentinas. Especies nuevas, adiciones y correcciones". Revista Argentina de Historia Natural. 1: 240–259.
  11. 1 2 Ameghino, F. (1895). Sur les oiseaux fossils de patagonie et le faune mammalogique des couches á Pyrotherium. Premiére contribution á la connissance de la faune mammalogique des couches á Pyrotherium. Boletín del Instituto Geografico Argentino, 15, 603-660.
  12. 1 2 3 4 Andrews, C. W. (1899). "On the Extinct Birds of Patagonia .–I. The Skull and Skeleton of Phororhacos inflatus Ameghino". The Transactions of the Zoological Society of London. 15 (3): 55–86. doi:10.1111/j.1096-3642.1899.tb00019.x. ISSN   0084-5620.
  13. ↑ Ameghino, F. 1895. Sobre las aves fósiles de Patagonia. Boletin del Instituto Geografico da Argentina, 15:501-602.
  14. ↑ Sinclair, W. J., & Farr, M. S. (1932). Aves of the Santa Cruz beds (Vol. 2). The University.
  15. ↑ Degrange, Federico J.; Noriega, Jorge I.; Areta, Juan I. (2012), Vizcaino, Sergio F.; Kay, Richard F.; Bargo, M. Susana (eds.), "Diversity and paleobiology of the Santacrucian birds", Early Miocene Paleobiology in Patagonia, Cambridge: Cambridge University Press, pp. 138–155, doi:10.1017/cbo9780511667381.010, ISBN   978-0-511-66738-1 , retrieved 4 May 2022
  16. 1 2 3 Blanco, R. Ernesto; Washington W. Jones, Terror birds on the run: a mechanical model to estimate its maximum running speed. Proceedings of the Royal Society 272 (no. 1574): 1769-1773 (September 2005). Retrieved August 2012.
  17. ↑ Early Miocene Paleobiology in Patagonia: High-Latitude Paleocommunities of Patagonia" [1], geredigeerd door Sergio F. Vizcaíno, Sergio F. Vizcno, Richard F. Kay en M. Susana Bargo
  18. 1 2 3 4 Degrange, Federico J.; Tambussi, Claudia P.; Taglioretti, Matías L.; Dondas, Alejandro; Scaglia, Fernando (4 March 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 . ISSN   0272-4634. S2CID   85212917.
  19. ↑ Jones, G. M., & Spells, K. E. (1963). A theoretical and comparative study of the functional dependence of the semicircular canal upon its physical dimensions. Proceedings of the Royal Society of London. Series B. Biological Sciences, 157(968), 403-419.
  20. ↑ Degrange, F.J.; Tambussi, C.P.; Taglioretti, M.L.; Dondas, A.; Scaglia, F. (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.
  21. 1 2 3 4 Croft, D. A. (2016). Horned armadillos and rafting monkeys: the fascinating fossil mammals of South America. Indiana University Press.
  22. 1 2 Townsend, K. B., & Croft, D. A. (2008). Diets of notoungulates from the Santa Cruz Formation, Argentina: new evidence from enamel microwear. Journal of Vertebrate Paleontology, 28(1), 217-230.
  23. 1 2 Cuitiño, J. I., Fernicola, J. C., Raigemborn, M. S., & Krapovickas, V. (2019). Stratigraphy and depositional environments of the Santa Cruz Formation (early–middle Miocene) along the Río Santa Cruz, southern Patagonia, Argentina. Publicación Electrónica de la Asociación Paleontológica Argentina, 19(2).
  24. ↑ Kay, Richard F.; Vizcaíno, Sergio F.; Bargo, M. Susana; Spradley, Jackson P.; Cuitiño, José I. (1 August 2021). "Paleoenvironments and paleoecology of the Santa Cruz Formation (early-middle Miocene) along the Río Santa Cruz, Patagonia (Argentina)". Journal of South American Earth Sciences. 109: 103296. Bibcode:2021JSAES.10903296K. doi: 10.1016/j.jsames.2021.103296 . ISSN   0895-9811. S2CID   233693434.
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