Saltasaurus (which means "lizard from Salta") is a genus of saltasauriddinosaur of the Late Cretaceousperiod of Argentina. Small among sauropods, though still heavy by the standards of modern creatures, Saltasaurus was characterized by a short neck and stubby limbs. It was the first genus of sauropod known to possess armour of bony plates embedded in its skin. Such small bony plates, called osteoderms, have since been found on other titanosaurians.
The fossils of Saltasaurus were excavated by José Bonaparte, Martín Vince and Juan C. Leal between 1975 and 1977 at the Estancia "El Brete". The find was in 1977 reported in the scientific literature.[1]
Saltasaurus was named and described by Bonaparte and Jaime E. Powell in 1980. The type species is Saltasaurus loricatus. Its generic name is derived from Salta Province, the region of north-west Argentina where the first fossils were recovered. The specific name means "protected by small armoured plates" in Latin.[2]
The holotype, PVL 4017-92, was found in a layer of the Lecho Formation dating from the early Maastrichtian stage of the Upper Cretaceous period, about seventy million years old. It consists of a sacrum connected to two ilia. Under the inventory number PVL 4017 over two hundred additional fossils have been catalogued. These include rear skull elements, teeth, vertebrae of the neck, back, hip and tail, parts of the shoulder girdle and the pelvis, and limb bones — plus various pieces of armour. These bones represent a minimum of five individuals, two adults and three juveniles or subadults.[3]
Currently the only recognised species of Saltasaurus is S. loricatus. A S. robustus and a S. australis have been suggested but these are now considered to belong to a separate genus, Neuquensaurus. Earlier, armour plates from the area had been named as Loricosaurus by Friedrich von Huene who assumed them to be from an armoured ankylosaurian. It has been suggested these plates were in fact from Saltasaurus.
DescriptionEdit
Saltasaurus herd passes Quilmesaurus and NoasaurusSize comparison of Saltasaurus, size based on Donald Henderson
Saltasaurus is very small compared to most other members of the Sauropoda. Powell estimated the adult length at six metres. In 2010, Gregory S. Paul estimated the maximum length at 8.5 metres (28 ft), the weight at 2.5 tonnes (2.8 short tons).[4]
The teeth of Saltasaurus were cylindrical, with spatulate points. Saltasaurus had a relatively short neck with shortened neck vertebrae. The vertebrae from the middle part of its tail had elongated centra.[5]Saltasaurus had vertebral lateral fossae, pleurocoels, that resembled shallow depressions.[6] Fossae that similarly resemble shallow depressions are known from Malawisaurus, Alamosaurus, Aeolosaurus, and Gondwanatitan.[6]Venenosaurus also had depression-like fossae, but its pleurocoels penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns.[6] In Saltasaurus, the vertebral bone was generally cancellous and there were larger air chambers present as well. The limbs were short and stubby with especially short hands and feet. Saltasaurus had more robust radii than Venenosaurus.[7] The belly was extremely wide.
The osteoderms came in two types. There were larger oval plates with a length of up to twelve centimetres. These were keeled or spiked and perhaps were ordered in longitudinal rows along the back. The second type consists of small ossicles, rounded or pentagonal, about seven millimetres in diameter, that formed a continuous armour between the plates. A study in 2010 concluded that the larger plates had cancellous bone but that the ossicles had a denser bone tissue.[8]
Like all sauropods, Saltasaurus was herbivorous. Because of its barrel-like rump, shaped like a hippopotamus, Powell suggested that Saltasaurus was aquatic. Despite its small stature, Saltasaurus was still graviportal like other sauropods, meaning it could not run because its hindlimbs had to be held straight at the load-bearing phase of their walking cycle. Powell assumed adult individuals were protected against predators by their body armour, while juveniles were protected by the herd as a whole.[3]
In the Cretaceous Period, sauropods in North America were no longer the dominant group of herbivorous dinosaurs with the exception of Alamosaurus, with the ornithopod and ceratopsian dinosaurs, such as Edmontosaurus and Triceratops, becoming the most abundant (this being most evident by the Late Cretaceous epoch). However, on other landmasses such as South America and Africa (which were island continents much like modern Australia) sauropods, in particular the titanosaurs, continued to be the dominant herbivores.
Saltasaurus was one such titanosaur sauropod, and lived around 70 million years ago. When it was first discovered, in 1975, it forced palaeontologists to reconsider some assumptions about sauropods as Saltasaurus possessed crocodile-like armour (osteoderms) 10 to 12 centimetres (4 to 5 in) in diameter. Previously, it had been assumed that size alone was sufficient defence for the massive sauropods. Since then, palaeontologists have investigated the possibility that other sauropods may also have had armour; for example, Laplatasaurus.
A new discovery, from another formation, may shed light on the nesting habits of Saltasaurus. A large titanosaurid nesting ground was discovered in Auca Mahuevo, in Patagonia, Argentina (another titanosaur nesting site has reportedly been discovered in Spain). Several hundred female saltasaurines dug holes with their back feet, laid eggs in clutches averaging around 25 eggs each, and buried the nests under dirt and vegetation. The small eggs, about 11–12 cm (4–5 in) in diameter, contained fossilisedembryos, complete with skin impressions showing a mosaic armour of small bead-like scales. The armour pattern resembled that of Saltasaurus.[9]
FootnotesEdit
^J.F. Bonaparte, J.A. Salfity, G. Bossi & J.E. Powell, 1977, "Hallazgo de dinosaurios y aves cretacicas en la Formación Lecho de El Brete (Salta), proximo al limite con Tucumán", Acta Geològica Lilloana14: 5-17
^J.F. Bonaparte and J.E. Powell, 1980, "A continental assemblage of tetrapods from the Upper Cretaceous beds of El Brete, northwestern Argentina (Sauropoda-Coelurosauria-Carnosauria-Aves)," Mémoires de la Société Géologique de France, Nouvelle Série139: 19-28
^ abPowell, J.E., 1992, "Osteología de Saltasaurus loricatus (Sauropoda Titanosauridae) del Cretácico Superior del noroeste Argentino" In: Sanz, J., Buscalioni, A. (Eds.), Los dinosaurios y su entorno biótico: Actas del Segundo Curso de Paleontología in Cuenca, pp. 165-230
^Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 213
^"Caudal Vertebrae," Tidwell, Carpenter, and Meyer (2001). Page 145.
^ abc"Caudal Vertebrae," Tidwell, Carpenter, and Meyer (2001). Page 147.
^"Forelimb," Tidwell, Carpenter, and Meyer (2001). Page 148.
^Ignacio A. Cerda and Jaime E. Powell, 2010, "Dermal Armor Histology of Saltasaurus loricatus, an Upper Cretaceous Sauropod Dinosaur from Northwest Argentina", Acta Palaeontologica Polonica, 55(3): 389-398
Coria, R.A. and Chiappe, L.M. 2007.Embryonic Skin From Late Cretaceous Sauropods (Dinosauria) of Auca Mahuevo, Patagonia, Argentina. Journal of Paleontology v81(6):1528-1532 doi:10.1666/05-150.1
Tidwell, V., Carpenter, K. & Meyer, S. 2001. New Titanosauriform (Sauropoda) from the Poison Strip Member of the Cedar Mountain Formation (Lower Cretaceous), Utah. In: Mesozoic Vertebrate Life. D. H. Tanke & K. Carpenter (eds.). Indiana University Press, Eds. D.H. Tanke & K. Carpenter. Indiana University Press. 139–165.
Further readingEdit
Walking on Eggs: The Astonishing Discovery of Thousands of Dinosaur Eggs in the Badlands of Patagonia, by Luis Chiappe and Lowell Dingus. June 19, 2001, Scribner. ISBN0-7432-1211-8.
External linksEdit
Wikispecies has information related to Saltasaurus.
Wikimedia Commons has media related to Saltasaurus.
, by M. Alan Kazlev, from Palæos.
The late Cretaceous nesting grounds of Patagonia, by Luis V. Rey, from his art gallery.
saltasaurus, which, means, lizard, from, salta, genus, saltasaurid, dinosaur, late, cretaceous, period, argentina, small, among, sauropods, though, still, heavy, standards, modern, creatures, characterized, short, neck, stubby, limbs, first, genus, sauropod, k. Saltasaurus which means lizard from Salta is a genus of saltasaurid dinosaur of the Late Cretaceous period of Argentina Small among sauropods though still heavy by the standards of modern creatures Saltasaurus was characterized by a short neck and stubby limbs It was the first genus of sauropod known to possess armour of bony plates embedded in its skin Such small bony plates called osteoderms have since been found on other titanosaurians SaltasaurusTemporal range Late Cretaceous 70 68 Ma PreꞒ Ꞓ O S D C P T J K Pg N Life restorationScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClade DinosauriaClade SaurischiaClade SauropodomorphaClade SauropodaClade MacronariaClade TitanosauriaClade LithostrotiaFamily SaltasauridaeGenus SaltasaurusBonaparte amp Powell 1980Species S loricatusBinomial name Saltasaurus loricatusBonaparte amp Powell 1980SynonymsLoricosaurus scutatus von Huene 1929 Contents 1 Discovery 2 Description 3 Palaeobiology 4 Footnotes 5 References 6 Further reading 7 External linksDiscovery Edit nbsp A large osteodermThe fossils of Saltasaurus were excavated by Jose Bonaparte Martin Vince and Juan C Leal between 1975 and 1977 at the Estancia El Brete The find was in 1977 reported in the scientific literature 1 Saltasaurus was named and described by Bonaparte and Jaime E Powell in 1980 The type species is Saltasaurus loricatus Its generic name is derived from Salta Province the region of north west Argentina where the first fossils were recovered The specific name means protected by small armoured plates in Latin 2 The holotype PVL 4017 92 was found in a layer of the Lecho Formation dating from the early Maastrichtian stage of the Upper Cretaceous period about seventy million years old It consists of a sacrum connected to two ilia Under the inventory number PVL 4017 over two hundred additional fossils have been catalogued These include rear skull elements teeth vertebrae of the neck back hip and tail parts of the shoulder girdle and the pelvis and limb bones plus various pieces of armour These bones represent a minimum of five individuals two adults and three juveniles or subadults 3 Currently the only recognised species of Saltasaurus is S loricatus A S robustus and a S australis have been suggested but these are now considered to belong to a separate genus Neuquensaurus Earlier armour plates from the area had been named as Loricosaurus by Friedrich von Huene who assumed them to be from an armoured ankylosaurian It has been suggested these plates were in fact from Saltasaurus Description Edit nbsp Saltasaurus herd passes Quilmesaurus and Noasaurus nbsp Size comparison of Saltasaurus size based on Donald HendersonSaltasaurus is very small compared to most other members of the Sauropoda Powell estimated the adult length at six metres In 2010 Gregory S Paul estimated the maximum length at 8 5 metres 28 ft the weight at 2 5 tonnes 2 8 short tons 4 The teeth of Saltasaurus were cylindrical with spatulate points Saltasaurus had a relatively short neck with shortened neck vertebrae The vertebrae from the middle part of its tail had elongated centra 5 Saltasaurus had vertebral lateral fossae pleurocoels that resembled shallow depressions 6 Fossae that similarly resemble shallow depressions are known from Malawisaurus Alamosaurus Aeolosaurus and Gondwanatitan 6 Venenosaurus also had depression like fossae but its pleurocoels penetrated deeper into the vertebrae were divided into two chambers and extend farther into the vertebral columns 6 In Saltasaurus the vertebral bone was generally cancellous and there were larger air chambers present as well The limbs were short and stubby with especially short hands and feet Saltasaurus had more robust radii than Venenosaurus 7 The belly was extremely wide The osteoderms came in two types There were larger oval plates with a length of up to twelve centimetres These were keeled or spiked and perhaps were ordered in longitudinal rows along the back The second type consists of small ossicles rounded or pentagonal about seven millimetres in diameter that formed a continuous armour between the plates A study in 2010 concluded that the larger plates had cancellous bone but that the ossicles had a denser bone tissue 8 Palaeobiology Edit nbsp Egg on display at the North American Museum of Ancient LifeLike all sauropods Saltasaurus was herbivorous Because of its barrel like rump shaped like a hippopotamus Powell suggested that Saltasaurus was aquatic Despite its small stature Saltasaurus was still graviportal like other sauropods meaning it could not run because its hindlimbs had to be held straight at the load bearing phase of their walking cycle Powell assumed adult individuals were protected against predators by their body armour while juveniles were protected by the herd as a whole 3 In the Cretaceous Period sauropods in North America were no longer the dominant group of herbivorous dinosaurs with the exception of Alamosaurus with the ornithopod and ceratopsian dinosaurs such as Edmontosaurus and Triceratops becoming the most abundant this being most evident by the Late Cretaceous epoch However on other landmasses such as South America and Africa which were island continents much like modern Australia sauropods in particular the titanosaurs continued to be the dominant herbivores Saltasaurus was one such titanosaur sauropod and lived around 70 million years ago When it was first discovered in 1975 it forced palaeontologists to reconsider some assumptions about sauropods as Saltasaurus possessed crocodile like armour osteoderms 10 to 12 centimetres 4 to 5 in in diameter Previously it had been assumed that size alone was sufficient defence for the massive sauropods Since then palaeontologists have investigated the possibility that other sauropods may also have had armour for example Laplatasaurus A new discovery from another formation may shed light on the nesting habits of Saltasaurus A large titanosaurid nesting ground was discovered in Auca Mahuevo in Patagonia Argentina another titanosaur nesting site has reportedly been discovered in Spain Several hundred female saltasaurines dug holes with their back feet laid eggs in clutches averaging around 25 eggs each and buried the nests under dirt and vegetation The small eggs about 11 12 cm 4 5 in in diameter contained fossilised embryos complete with skin impressions showing a mosaic armour of small bead like scales The armour pattern resembled that of Saltasaurus 9 Footnotes Edit J F Bonaparte J A Salfity G Bossi amp J E Powell 1977 Hallazgo de dinosaurios y aves cretacicas en la Formacion Lecho de El Brete Salta proximo al limite con Tucuman Acta Geologica Lilloana 14 5 17 J F Bonaparte and J E Powell 1980 A continental assemblage of tetrapods from the Upper Cretaceous beds of El Brete northwestern Argentina Sauropoda Coelurosauria Carnosauria Aves Memoires de la Societe Geologique de France Nouvelle Serie 139 19 28 a b Powell J E 1992 Osteologia de Saltasaurus loricatus Sauropoda Titanosauridae del Cretacico Superior del noroeste Argentino In Sanz J Buscalioni A Eds Los dinosaurios y su entorno biotico Actas del Segundo Curso de Paleontologia in Cuenca pp 165 230 Paul G S 2010 The Princeton Field Guide to Dinosaurs Princeton University Press p 213 Caudal Vertebrae Tidwell Carpenter and Meyer 2001 Page 145 a b c Caudal Vertebrae Tidwell Carpenter and Meyer 2001 Page 147 Forelimb Tidwell Carpenter and Meyer 2001 Page 148 Ignacio A Cerda and Jaime E Powell 2010 Dermal Armor Histology of Saltasaurus loricatus an Upper Cretaceous Sauropod Dinosaur from Northwest Argentina Acta Palaeontologica Polonica 55 3 389 398 Coria and Chiappe 2007 References EditCoria R A and Chiappe L M 2007 Embryonic Skin From Late Cretaceous Sauropods Dinosauria of Auca Mahuevo Patagonia Argentina Journal of Paleontology v81 6 1528 1532 doi 10 1666 05 150 1 Tidwell V Carpenter K amp Meyer S 2001 New Titanosauriform Sauropoda from the Poison Strip Member of the Cedar Mountain Formation Lower Cretaceous Utah In Mesozoic Vertebrate Life D H Tanke amp K Carpenter eds Indiana University Press Eds D H Tanke amp K Carpenter Indiana University Press 139 165 Further reading EditWalking on Eggs The Astonishing Discovery of Thousands of Dinosaur Eggs in the Badlands of Patagonia by Luis Chiappe and Lowell Dingus June 19 2001 Scribner ISBN 0 7432 1211 8 External links Edit nbsp Wikispecies has information related to Saltasaurus nbsp Wikimedia Commons has media related to Saltasaurus Sauropodomorpha Titanosauridae Saltasaurus by M Alan Kazlev from Palaeos The late Cretaceous nesting grounds of Patagonia by Luis V Rey from his art gallery nbsp Dinosaurs portal Retrieved from https en wikipedia org w index php title Saltasaurus amp oldid 1150702461, wikipedia, wiki, book, books, library,
