Puertasaurus

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Puertasaurus
Temporal range: Late Cretaceous 76–70  Ma
Puertasaurus Skeletal V2.svg
Skeletal diagram with known material in white and unknown material restored in gray
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade:† Sauropodomorpha
Clade:† Sauropoda
Clade:† Macronaria
Clade:† Titanosauria
Clade:† Lognkosauria
Genus:† Puertasaurus
Novas et al., 2005
Type species
†Puertasaurus reuili
Novas et al., 2005

Puertasaurus is a genus of sauropod dinosaur that lived in South America during the Late Cretaceous Period. It is known from a single specimen recovered from sedimentary rocks of the Cerro Fortaleza Formation in southwestern Patagonia, Argentina, which probably is Campanian or Maastrichtian in age. The only species is Puertasaurus reuili. Described by the paleontologist Fernando Novas and colleagues in 2005, it was named in honor of Pablo Puerta and Santiago Reuil, who discovered and prepared the specimen. It consists of four well-preserved vertebrae, including one cervical, one dorsal, and two caudal vertebrae. Puertasaurus is a member of Titanosauria, the dominant group of sauropods during the Cretaceous.

Contents

Puertasaurus was a very large animal. Its size is difficult to estimate due to the scarcity of its remains, but current estimates place it around 30 meters (98 feet) long and 50 metric tons (55 short tons) in mass. The largest of the four preserved bones is the dorsal vertebra, which at 1.68 meters (5 ft 6 in) wide is the broadest known vertebra of any sauropod. The Cerro Fortaleza Formation is of uncertain age, due to the inconsistency of stratigraphic nomenclature in Patagonia. When Puertasaurus was alive, the Cerro Fortaleza Formation would have been a humid, forested landscape. Puertasaurus would have shared its habitat with other dinosaurs, including another large sauropod, Dreadnoughtus , in addition to other reptiles and fish.

Discovery and naming

The holotype and only known specimen of Puertasaurus reuili was discovered in the Santa Cruz Province of southern Patagonia, Argentina. The remains were recovered in Cerro Los Hornos, near the La Leona River, and were reported from the Cerro Fortaleza Formation (which, at the time, was referred to as the Pari Aike Formation). [1] The holotype was discovered in a grey sandstone lens that also preserved the carbonized remains of cycads and conifers. It was given the specimen number of MPM 10002, and consists of four disarticulated vertebrae, specifically one cervical, one dorsal, and two caudal vertebrae (about 3% of the skeleton). [2] Of this material, only the dorsal vertebra was complete. Most of the cervical vertebra was preserved, but only the centra of the caudal vertebrae are known. Puertasaurus reuilli was described by the paleontologists Fernando Novas, Leonardo Salgado, Jorge Calvo, and Federico Agnolin in 2005, and was named after the fossil hunters Pablo Puerta and Santiago Reuil, who discovered the holotype in January 2001 and prepared it afterwards. Its discovery was announced in July 2006, at the Argentine Museum of Natural Sciences in Buenos Aires. [3] Puertasaurus was the first discovered giant titanosaur that preserved cervical vertebrae. [4]

Description

Size

Life restoration based on related taxa Puertasaurus reuili.png
Life restoration based on related taxa

Due to a lack of better material, the size of Puertasaurus is difficult to estimate. [5] Novas estimated the new species was approximately 35 to 40 meters (115 to 131 ft) long and weighing between 80 and 100 metric tons (88 and 110 short tons). [3] This would place it as one of the largest dinosaurs, only rivaled in size by its relative Argentinosaurus , which has been estimated at up to 39.7 meters (130 ft) in length and 90 metric tons (99 short tons) in mass. [6] [7] The discovery of the more complete Futalognkosaurus revealed that these previous estimates were likely too high, and suggested that giants such as Puertasaurus and Argentinosaurus were probably less than 33 meters (108 ft) long. [8] In 2012, Thomas Holtz estimated Puertasaurus to have been potentially 30 meters (98 feet) long and 72.5-80 tonnes (80-88 short tons). [9] [10] In 2013, the entire neck was estimated to have been approximately 9 meters (30 feet) long by Mike Taylor and Matt Wedel. [11] Later the same year, Scott Hartman made a reconstruction that suggests a total length of 27 meters (89 feet), slightly shorter than other estimates. [12] In 2016, Gregory S. Paul estimated a length of 30 meters (98 feet) and a weight of at least 50 metric tons (55 short tons). [13] In 2017, paleontologist José Carballido and his colleagues estimated its mass at roughly 60 metric tons (66 short tons), which was lighter than Patagotitan , a more complete giant sauropod. [14] In 2019, Gregory S. Paul estimated the mass of Puertasaurus to be in the size range of Patagotitan at 45–55 tonnes (50–61 short tons). [15]

Vertebrae

Dorsal vertebra Saurischia - Puertasaurus reuili.JPG
Dorsal vertebra

Of the four vertebrae preserved in the holotype, the largest is the dorsal vertebra (thought to be a second dorsal vertebra), measuring 1.06 meters (3 ft 6 in) tall and 1.68 meters (5 ft 6 in) wide. This is the broadest sauropod vertebra known, and two-thirds of its width is made up of the huge transverse processes (structures projecting from the side of the vertebra), which are heavily expanded and have very deep bases, forming wing-like structures when viewed from the front. In other titanosaurs, such as Dreadnoughtus , they are far less wide and deep. [16] In Puertasaurus, these processes are perpendicular to the axial plane. Craniocaudally (front to back), however, the vertebra is rather short, shorter than average among titanosaurs. The centrum is especially opisthocoelous (having a convex front and a concave rear). The laminae in the neural arch are robust, although reduced. Hyposphene-hypantrum articulation (two structures on two vertebrae that fit into each other and form an extra joint) is not present, like other titanosaurs. The pre- and postspinal fossae are especially deep and broad. The pre- and postspinal laminae (structures on the upper half of the vertebra) are robust. The neural spine is oriented vertically (perpendicular to the centrum) but dorsoventrally (top to bottom) low, although it is extremely transversely (side to side) expanded. This orientation is unlike that of more derived titanosaurs, instead it is similar to basal ones (such as Argentinosaurus) and other sauropods, such as Euhelopus . [4]

The cervical vertebra was also notably large, with a transverse width of 140 centimeters (55 inches) (including the cervical ribs ). It is thought to be the ninth vertebra in the neck. The cervical ribs are fused to the centrum. The centrum is especially dorsoventrally compressed. The pre- and postspinal fossae on the neural spine are wide and deep. This, along with the expanded distal (front) end of the vertebra, provide evidence of powerful neck ligaments and muscles. These features are also known in other titanosaurs but are extremely prominent in Puertasaurus. The neural spine was especially tall and laterally (sideways) expanded, to the point where it would exceed the length of the centrum. This would make it have one of the proportionately largest neural spines of any titanosaur. The apex of the neural spine was positioned on the posterior side of the vertebral midline. [16] The spinoprezygapophyseal laminae (the spike-like projection in front of the neural spine) are separated from each other and only touch the middle of the neural spine. [17] The zygapophyseal articulations, which connect two adjacent vertebrae, are located on the lower part the neural arch. The diapophyses and parapophyses (processes on the side of the vertebra) are strongly laterally projected. The cervical vertebra lacks pleurocoels (large cavities) and was not very pneumatic. The length of the restored centrum is estimated to be 105 centimeters (41 inches) long based on other titanosaurs. [4]

Two caudal vertebrae from the middle of the tail were also preserved. They are standard in shape for titanosaurs and are procoelous (having a concave front and a convex rear). [4] Little else is known about them since they were never described in detail. [18]

Classification

Dorsal vertebra (right) compared with a vertebra of Argentinosaurus, temporarily exhibited at the Museum Koenig Argentinosaurus and Puertasaurus vertebrae.jpg
Dorsal vertebra (right) compared with a vertebra of Argentinosaurus , temporarily exhibited at the Museum Koenig
Neck reconstructions of Puertasaurus and other sauropods Sauropod neck reconstructions.png
Neck reconstructions of Puertasaurus and other sauropods

Puertasaurus is differentiated from other sauropods based on a unique combination of features. These features consist of the heavily expanded neural spines on the cervical vertebrae, which result in the neural spines being wider than the vertebral body, strong dorsolateral (high on the side) ridges on these neural spines, robust spinoprezygapophyseal laminae (projections in front of the neural spine) on the posterior cervical vertebrae, anterior dorsal vertebrae that are very short from front to back, and the animal's giant size. [4]

Puertasaurus belonged to the clade Titanosauria, one of the most diverse groups of sauropods. It is a member of the group Lognkosauria, which includes several other large titanosaurs, including Futalognkosaurus, Patagotitan, Argentinosaurus, Notocolossus , Mendozasaurus , and Quetecsaurus . Many of these animals, such as Argentinosaurus and Patagotitan, were especially massive. Puertasaurus is generally recovered as a stable (a firm member of the group) lognkosaur, although in 2017, Carballido found it (along with Quetecsaurus) to be the least stable members of the group. [2] [14] [19]

The following cladogram shows the position of Puertasaurus in Lognkosauria according to Gonzalez Riga and colleagues, 2018. [19]

Lognkosauria

Paleoecology

Skeleton of Talenkauen, a dinosaur from the same formation as Puertasaurus Talenkauen.jpg
Skeleton of Talenkauen , a dinosaur from the same formation as Puertasaurus

Puertasaurus is from the Late Cretaceous Period of southern Patagonia. However, which formation it was derived from and its geological age have been disputed, because of the inconsistent stratigraphic nomenclature of southern Patagonia. It was originally reported as being from the Pari Aike Formation, and Maastrichtian in age. The Pari Aike Formation was subsequently reassigned to the Mata Amarilla Formation and reinterpreted as being from the Cenomanian to Santonian. [20] More recent studies have stated that these deposits pertain to the Cerro Fortaleza Formation, which was dated to the Campanian or Maastrichtian (approximately 76 to 70 million years ago). [16] The rocks of the formation mostly consist of sandstone beds, along with layers of mudstone and lignitic horizons. [1]

The Cerro Fortaleza Formation represents a terrestrial ecosystem. The presence of paleosols and lignite suggests a humid environment with high amounts of rainfall and a high water table. Avulsion surfaces, histosols, carbonaceous fossil roots, and silicified wood all provide evidence of a low-lying forested landscape with poor drainage. [4] Other dinosaurs from the same locality include the ornithopod Talenkauen , the theropods Orkoraptor and Austrocheirus , and the sauropod Dreadnoughtus . [16] [21] [22] Non-dinosaurian fauna known from the formation include crocodilians, turtles, bony fish, and lamniform sharks. [1] [23] [24]

Related Research Articles

<i>Argentinosaurus</i> Late Cretaceous giant sauropod dinosaur genus

Argentinosaurus is a genus of giant sauropod dinosaur that lived during the Late Cretaceous period in what is now Argentina. Although it is only known from fragmentary remains, Argentinosaurus is one of the largest known land animals of all time, perhaps the largest, measuring 30–35 m (98–115 ft) long and weighing 65–80 t. It was a member of Titanosauria, the dominant group of sauropods during the Cretaceous. It is widely regarded by many paleontologists as the biggest dinosaur ever, and perhaps lengthwise the longest animal ever, though both claims have no concrete evidence yet.

<i>Antarctosaurus</i> Sauropod dinosaur genus from Late Cretaceous

Antarctosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The type species, Antarctosaurus wichmannianus, and a second species, Antarctosaurus giganteus, were described by prolific German paleontologist Friedrich von Huene in 1929. Three additional species of Antarctosaurus have been named since then but later studies have considered them dubious or unlikely to pertain to the genus.

<i>Andesaurus</i> Extinct genus of dinosaurs

Andesaurus is a genus of basal titanosaurian sauropod dinosaur which existed during the middle of the Cretaceous Period in South America. Like most sauropods, belonging to one of the largest animals ever to walk the Earth, it would have had a small head on the end of a long neck and an equally long tail.

<i>Brachytrachelopan</i> Extinct genus of dinosaurs

Brachytrachelopan is a short-necked sauropod dinosaur from the Late Jurassic of Argentina. The holotype and only known specimen was collected from an erosional exposure of fluvial sandstone within the Cañadón Calcáreo Formation on a hill approximately 25 kilometres (16 mi) north-northeast of Cerro Cóndor, Chubut Province, in west-central Argentina, South America. Though very incomplete, the skeletal elements recovered were found in articulation and include eight cervical, twelve dorsal, and three sacral vertebrae, as well as proximal portions of the posterior cervical ribs and all the dorsal ribs, the distal end of the left femur, the proximal end of the left tibia, and the right ilium. Much of the specimen was probably lost to erosion many years before its discovery. The type species is Brachytrachelopan mesai. The specific name honours Daniel Mesa, a local shepherd who discovered the specimen while searching for lost sheep. The genus name translates as "short-necked Pan", Pan being the god of the shepherds.

<i>Futalognkosaurus</i> Extinct genus of dinosaurs

Futalognkosaurus is a genus of titanosaurian dinosaur. The herbivorous Futalognkosaurus lived approximately 87 million years ago in the Portezuelo Formation, in what is now Argentina, of the Coniacian stage of the late Cretaceous Period. The fish and fossilized leaf debris on the site, together with other dinosaur remains, suggest a warm tropical climate in Patagonia during this period.

<i>Neuquensaurus</i> Extinct genus of dinosaurs

Neuquensaurus is a genus of saltasaurid sauropod dinosaur that lived in the Late Cretaceous, about 80 million years ago in Argentina in South America. Its fossils were recovered from outcrops of the Anacleto Formation around Cinco Saltos, near the Neuquén river from which its name is derived.

<i>Rocasaurus</i> Genus of titanosaurian sauropod from the Late Cretaceous period

Rocasaurus is a genus of titanosaurian sauropod that lived in South America. Rocasaurus was discovered in Argentina in 2000, within the Allen Formation which is dated to be middle Campanian to early Maastrichtian in age. This genus grew up to 8 metres (26 ft) long, making it one of the smaller sauropods. It seems to be closely related to saltasaurid dinosaurs, like Saltasaurus and Neuquensaurus.

<i>Pellegrinisaurus</i> Extinct genus of dinosaurs

Pellegrinisaurus is a genus of titanosaurian sauropod dinosaur that lived in South America during the Late Cretaceous period. The holotype was found in the Allen Formation, Argentina.

The Cerro Fortaleza Formation, in older literature described as Pari Aike Formation, is a Late Cretaceous geologic formation of Campanian to Maastrichtian age of the Austral Basin in southern Patagonia, Argentina.

<span class="mw-page-title-main">Lognkosauria</span> Clade of titanosaurian sauropods

Lognkosauria is a clade of giant long-necked sauropod dinosaurs within the clade Titanosauria. It includes some of the largest and heaviest dinosaurs known. They lived in South America and likely Asia during the Late Cretaceous period.

<i>Atacamatitan</i> Extinct genus of dinosaurs

Atacamatitan is a genus of titanosaurian sauropod dinosaurs from the Late Cretaceous Tolar Formation of Chile.

<i>Katepensaurus</i> Extinct genus of rebbachisaurid dinosaurs

Katepensaurus is an extinct genus of rebbachisaurid sauropod dinosaur known from the Late Cretaceous of south-central Chubut Province of central Patagonia, Argentina. It contains a single species, Katepensaurus goicoecheai.

<i>Quetecsaurus</i> Extinct genus of dinosaurs

Quetecsaurus is a genus of titanosaurian sauropod dinosaur known from the Late Cretaceous of the southern Mendoza Province, western Argentina. It contains a single species, Quetecsaurus rusconii.

<i>Patagotitan</i> Extinct genus of dinosaurs

Patagotitan is a genus of titanosaurian sauropod dinosaur from the Cerro Barcino Formation in Chubut Province, Patagonia, Argentina. The genus contains a single species known from at least six young adult individuals, Patagotitan mayorum, which was first announced in 2014 and then named in 2017 by José Carballido and colleagues. Preliminary studies and press releases suggested that Patagotitan was the largest known titanosaur and land animal overall, with an estimated length of 37 m (121 ft) and an estimated weight of 69 tonnes. Later research revised the length estimate down to 31 m (102 ft) and weight estimates down to approximately 50–57 tonnes, suggesting that Patagotitan was of a similar size to, if not smaller than, its closest relatives Argentinosaurus and Puertasaurus. Still, Patagotitan is one of the most-known titanosaurs, and so its interrelationships with other titanosaurs have been relatively consistent in phylogenetic analyses. This led to its use in a re-definition of the group Colossosauria by Carballido and colleagues in 2022.

<i>Dreadnoughtus</i> Extinct genus of dinosaur

Dreadnoughtus is a genus of titanosaurian sauropod dinosaur containing a single species, Dreadnoughtus schrani. D. schrani is known from two partial skeletons discovered in Upper Cretaceous rocks of the Cerro Fortaleza Formation in Santa Cruz Province, Argentina. It is one of the largest terrestrial vertebrates known, with the immature type specimen measuring 26 metres (85 ft) in total body length and weighing 48–49 metric tons. D. schrani is known from more complete skeletons than any other gigantic titanosaurian.

<i>Notocolossus</i> Extinct genus of dinosaurs

Notocolossus is a genus of titanosaurian sauropod dinosaur from late Cretaceous strata of Mendoza Province, Argentina.

<i>Taurovenator</i> Extinct genus of reptiles

Taurovenator is a large carcharodontosaurid theropod from the late Cretaceous Huincul Formation of Argentina that lived during the Cenomanian age of the Late Cretaceous. It is monotypic, containing only one species, T. violantei.

<i>Austroposeidon</i> Extinct genus of dinosaurs

Austroposeidon is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Presidente Prudente Formation of Brazil. It contains one species, Austroposeidon magnificus.

<i>Pilmatueia</i> Sauropod dinosaur genus from the early Cretaceous Period

Pilmatueia is a diplodocoid sauropod belonging to the family Dicraeosauridae that lived in Argentina during the Early Cretaceous. Its type and only species is Pilmatueia faundezi. Pilmatueia was probably closely related to other South American dicraeosaurids such as Amargasaurus. Pilmatueia had relatively pneumatic vertebrae compared to other dicraeosaurids, which were otherwise characterized by a reduction in pneumaticity relative to other sauropods. Pilmatueia dates to the Valanginian, an age of the Cretaceous period for which dinosaur faunas are poorly known.

Kaijutitan is a genus of basal titanosaur dinosaur from the Sierra Barrosa Formation from Neuquén Province in Argentina. The type and only species is Kaijutitan maui.

References

  1. 1 2 3 Schroeter, E.R.; Egerton, V.M.; Ibiricu, L.M.; Lacovara, K.J. (2014). "Lamniform Shark Teeth from the Late Cretaceous of Southernmost South America (Santa Cruz Province, Argentina)". PLOS ONE . 9 (8): e104800. Bibcode:2014PLoSO...9j4800S. doi: 10.1371/journal.pone.0104800 . PMC   4139311 . PMID   25141301.
  2. 1 2 Calvo, J. O.; Porfiri, J. D.; González Riga, B. J.; Kellner, A. W. A. (2007). "Anatomy of Futalognkosaurus dukei Calvo, Porfiri, González Riga, & Kellner, 2007 (Dinosauria, Titanosauridae) from the Neuquen Group, Late Cretaceous, Patagonia, Argentina" (PDF). Arquivos do Museu Nacional. 65 (4): 511–526. Archived from the original (PDF) on July 13, 2011.
  3. 1 2 Roach, J. (2006). "Giant Dinosaur Discovered in Argentina". National Geographic News . Archived from the original on August 11, 2006. Retrieved November 20, 2018.
  4. 1 2 3 4 5 6 Novas, Fernando E.; Salgado, Leonardo; Calvo, Jorge; Agnolin, Federico (2005). "Giant titanosaur (Dinosauria, Sauropoda) from the Late Cretaceous of Patagonia". Revista del Museo Argentino de Ciencias Naturales. N.S. 7 (1): 37–41. doi: 10.22179/REVMACN.7.344 .
  5. ↑ Hartman, Scott (June 20, 2013). "The Problem With Puertasaurus". Skeletal Drawing. Retrieved November 20, 2018.
  6. ↑ Sellers, W. I.; Margetts, L.; Coria, R. A. B.; Manning, P. L. (2013). Carrier, David (ed.). "March of the Titans: The Locomotor Capabilities of Sauropod Dinosaurs". PLOS ONE. 8 (10): e78733. Bibcode:2013PLoSO...878733S. doi: 10.1371/journal.pone.0078733 . PMC   3864407 . PMID   24348896.
  7. ↑ Benson, Roger B. J.; Campione, Nicolás E.; Carrano, Matthew T.; Mannion, Phillip D.; Sullivan, Corwin; Upchurch, Paul; Evans, David C. (May 6, 2014). "Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage". PLOS Biology. 12 (5): e1001853. doi: 10.1371/journal.pbio.1001853 . PMC   4011683 . PMID   24802911.
  8. ↑ Calvo, Jorge O.; Juárez Valieri, Rubén D.; Porfiri, Juan D. (2008). "Re-sizing giants: estimation of body lenght[sic] of Futalognkosaurus dukei and implications for giant titanosaurian sauropods". Congreso Latinoamericano de Paleontología de Vertebrados. Retrieved November 20, 2018.
  9. ↑ Holtz, Tom (2012) Genus List for Holtz (2007) Dinosaurs
  10. ↑ Holtz, Thomas R. (2014). "Supplementary Information to Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages".
  11. ↑ Taylor, M.P.; Wedel, M.J. (2013). "Why sauropods had long necks; and why giraffes have short necks". PeerJ. 1: e36. doi: 10.7717/peerj.36 . PMC   3628838 . PMID   23638372.
  12. ↑ Hartman, Scott (2013). "The biggest of the big". Skeletal Drawing. Retrieved November 4, 2018.
  13. ↑ Paul, G.S. (2016) The Princeton Field Guide to Dinosaurs. 2nd ed. Princeton University Press p. 206
  14. 1 2 Carballido, José L.; et al. (2017). "A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs". Proc. R. Soc. B . 284 (1860): 20171219. doi:10.1098/rspb.2017.1219. PMC   5563814 . PMID   28794222.
  15. ↑ Paul, Gregory S. (2019). "Determining the largest known land animal: A critical comparison of differing methods for restoring the volume and mass of extinct animals" (PDF). Annals of the Carnegie Museum. 85 (4): 335–358. doi:10.2992/007.085.0403. S2CID   210840060.
  16. 1 2 3 4 Lacovara, Kenneth J.; Ibiricu, L.M.; Lamanna, M.C.; Poole, J.C.; Schroeter, E.R.; Ullmann, P.V.; Voegele, K.K.; Boles, Z.M.; Egerton, V.M.; Harris, J.D.; Martínez, R.D.; Novas, F.E. (September 4, 2014). "A Gigantic, Exceptionally Complete Titanosaurian Sauropod Dinosaur from Southern Patagonia, Argentina". Scientific Reports. 4: 6196. doi:10.1038/srep06196. PMC   5385829 . PMID   25186586.
  17. ↑ González Riga, Bernardo J.; David, Leonardo Ortiz (2014). "A new titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous (Cerro Lisandro Formation) of Mendoza Province, Argentina". Ameghiniana. 51 (1): 3–25. doi:10.5710/AMEGH.26.12.1013.1889. hdl: 11336/3819 . S2CID   129078730.
  18. ↑ Fowler, Denver W.; Sullivan, Robert M. (2011). "The first giant titanosaurian sauropod from the Upper Cretaceous of North America" (PDF). Acta Palaeontologica Polonica. 56 (4): 685–690. doi: 10.4202/app.2010.0105 .
  19. 1 2 Gonzalez Riga, B.J.; Mannion, P.D.; Poropat, S.F.; Ortiz David, L.; Coria, J.P. (2018). "Osteology of the Late Cretaceous Argentinean sauropod dinosaur Mendozasaurus neguyelap: implications for basal titanosaur relationships". Journal of the Linnean Society . 184 (1): 136–181. doi:10.1093/zoolinnean/zlx103. hdl: 10044/1/53967 .
  20. ↑ Varela, Augusto N.; Poiré, Daniel G.; Martin, Thomas; Gerdes, Axel; Goin, Francisco J.; Gelfo, Javier N.; Hoffmann, Simone (2012). "U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: its relationship with the evolution of the Austral Basin". Andean Geology. 39 (3): 359–379. doi: 10.5027/andgeoV39n3-a01 .
  21. ↑ Novas, Fernando E.; Martín D. Ezcurra; Agustina Lecuona (2008). "Orkoraptor burkei nov. gen. et sp., a large theropod from the Maastrichtian Pari Aike Formation, Southern Patagonia, Argentina". Cretaceous Research . 29 (3): 468–480. Bibcode:2008CrRes..29..468N. doi:10.1016/j.cretres.2008.01.001.
  22. ↑ Ezcurra, M.D.; Agnolin, F.L. & Novas, F.E. (2010). "An abelisauroid dinosaur with a non-atrophied manus from the Late Cretaceous Pari Aike Formation of southern Patagonia" (PDF). Zootaxa . 2450: 1–25. doi:10.11646/zootaxa.2450.1.1.
  23. ↑ Novas, Fernando E.; Cambiaso, Andrea V; Ambrioso, Alfredo (2004). "A new basal iguanodontian (Dinosauria, Ornithischia) from the Upper Cretaceous of Patagonia". Ameghiniana . 41 (1): 75–82.
  24. ↑ Goin, Francisco J.; et al. (2002). "Paleontología y Geología de los sedimentos del Cretácico Superior aflorantes al sur del río Shehuen (Mata Amarilla, Provincia de Santa Cruz, Argentina)". Actas del XV Congreso Geológico Argentino. 1.
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