Giganotosaurus (meaning "giant southern lizard") is an extinct genus of carcharodontosaurid theropod dinosaurs that lived in the Cenomanian of Argentina 99.6 - 97 mya. The holotype was discovered in the Candeleros Formation of Patagonia in 1993, and is about 70% complete. The animal was named Giganotosaurus carolinii in 1995; the genus name translates as "giant southern lizard" and the specific name honors the discoverer, Rubén D. Carolini.
It is one of the largest known terrestrial carnivores, slightly larger than Tyrannosaurus, but smaller than Spinosaurus. Its fossils have been found in Argentina.
A dentary bone, a tooth and some tracks, discovered before the holotype, were later assigned to this animal. The genus attracted much interest and became part of a scientific debate about the maximum sizes of theropod dinosaurs.
Description[]
Size (green) compared to that of other large theropods
The Giganotosaurus means "the giant southern lizard", as the Megalosaurus was the "giant lizard". It appeared superficially similar to other Carcharodontosaurs such as Carcharodontosaurus and Mapusaurus.
Giganotosaurus is the third or fourth largest predatory theropod dinosaur known, and assumed to being capable of hunting some of the largest sauropods in small groups. Giganotosaurus is the most popular member of Carcharodontosauridae along with Carcharodontosaurus. Giganotosaurus has two large bony brow ridges above its eyes, likely for sexual orientation.
Giganotosaurus has a slim build (in comparison to tyrannosaurids like Tyrannosaurus), built off of a large body; the carnivore had long, strong legs, robust forelimbs with large hooked claws, a long muscular tail and cutting jaws topped by a pair of sagittal crests. Giganotosaurus is thought to be the 4rth largest theropod dinosaurs known, competing with Tyrannosaurus, Spinosaurus, Tyrannotitan and other massive theropods that lived during the same time-frame. Some scientists put the maximum size at about 43 feet (13 meters long) 8 tons heavy and 12 feet tall at the hips. The relatively incomplete postcranial remains make it difficult to come to a solid conclusion; whereas the mass estimations go about 12 meters.
Life restoration
Giganotosaurus has smaller, robust arms, with hooked sickle claws, which could be used to subdue massive prey. Giganotosaurus has a pair of strange sagittal crests that start at the fenestra and nasal openings, and grow above the eye orbit, which then abruptly end. The crests overlook the orbits similar to that of an eave. Giganotosaurus' muscular jaws are filled with rows of sharp 8 inch long teeth. Giganotosaurus has an especially muscular neck, alongside a robust axis at the base of the neck.
Size[]
Comparison between the estimated sizes of the holotype (light green) and assigned specimen (dark green)
| Author | Length | Weight | Method |
|---|---|---|---|
| Frank Seebacher (2001) | 6.6 tons (7.3 short tons) | Using a polynomial method with body length, depth and width. | |
| Coria and Currie (2002) | 4.2 tons (4.6 short tons) | By using the 520-millimeter circumferance of the femoral shaft. | |
| Gerardo V. Mazzetta et al. (2004) | 8-10 tons (8.8-11.1 short tons)
6.5-8.2 tons (7.2-9 short tons) |
Based on tibia proportions and comparisons with Tyrannosaurus. | |
| François Therrien and Donald M. Henderson (2007) | Over 13.5 meters (44 feet)? | Over 13.8 tons (15.2 short tons)? | Based on reconstructed skulls that may or may not have been restored correctly. |
| Scott Hartman (2013) | 6.8-8.2 tons (7.5-9 short tons) | With Graphic Double Integration and references to his skeletals. | |
| The Sauropodomorph's Lair blog (2022) | ~10 meters (based on provided figure) | ~8.17 tonnes | By using a Python script to do a graphic double integration with one-pixel slices by 364px/meter intervals to find the overall volume. |
Discovery[]
Giganotosaurus carolinii was named after Ruben Carolini, an amateur fossil hunter, who discovered the fossils in the deposits of the Rio Limay Formation of Patagonia, southern Argentina, in 1993. It was published by Rodolfo Coria and Leonardo Selgado in the journal Nature in 1995.[1]
Holotype skeleton with reconstructed skull, arm, and feet, on the floor in Ernesto Bachmann Paleontological Museum
The holotype specimen's (MUCPv-Ch1) skeleton was about 70% complete and included the skull, pelvis, leg bones and most of the backbone. It is estimated around 12.2-12.5 m (40-41 ft) in length.[2][3] A second, more fragmentary, specimen (MUCPv-95) has also been recovered. It is only known from a portion of the left dentary which is 8% larger than the equivalent bone from the holotype. This largest Giganotosaurus specimen is estimated to represent an individual 13.2 m (43.3 ft) long, that weighed 6.2 tons.[4]Giganotosaurus might have had the longest known skull for a theropod dinosaur, with the holotype's skull estimated at 1.80 m (5'8' ft) and the second specimen's estimated at 1.95 m (6.3 ft).[5]
Giganotosaurus surpasses Tyrannosaurus rex in length by less than half a meter (the upper length estimate for T. rex is 13 m).[6] The most complete skeleton was housed at the Royal Ontario Museum until March 17, 2013. The Specimen (MUCPv-Ch1) is 70 percent complete and is only missing its arms and feet.
Classification[]
Reconstructed skeleton, Natural History Museum, Helsinki
Quadrate bone openings in various theropds; C (top) is Giganotosaurus
Coria and Salgado originally found Giganotosaurus to group more closely with the theropod clade Tetanurae than to more basal (Or "primitive") theropods such as ceratosaurs, due to shared features (synapomorphies) in the legs, skull, and pelvis. In 1996 Sereno and colleagues found Giganotosaurus, Carcharodontosaurus, and Acrocanthosaurus to be closely related within the superfamily Allosauroidea, and grouped them in the family Carcharodontosauridae. Features shared between these genera include the lacrimal and postorbital bones forming a broad "shelf" over the orbit, and the squared front end of the lower jaw.
Both Giganotosaurus and Mapusaurus have been placed in their own subfamily Giganotosaurinae by Coria and Currie in 2006 as more carcharodontosaurid dinosaurs are found and described, allowing interrelationships to be calculated.[2]
Paleobiology[]
Restoration
G. carolinii was slightly larger than T. rex, but had a brain only about half as big as those of tyrannosaurids.[7] The teeth of Tyrannosaurus were longer and wider, but more variable in size. The teeth of Giganotosaurus were shorter, less variable and narrower than those of Tyrannosaurus, and were more adapted for slicing flesh.[8] A well-developed olfactory region means that it probably had a good sense of smell. Its skull, although large, had a slender build.
Replica of Giganotosaurus at the Australian Museum in Sydney.
Titanosaur fossils have been recovered near the remains of Giganotosaurus, leading to speculation that these carnivores may have preyed on the giant herbivores. Fossils of related carcharodontosaurids grouped closely together may indicate pack hunting, a behavior that could possibly extend to Giganotosaurus itself.
Blanco and Mazzetta (2001) estimated that Giganotosaurus might have been capable of running at speeds up to 14 metres per second (31 mph).[9]
Giganotosaurus lived in Argentina alongside giant sauropods such as Limaysaurus and Andesaurus. It's closest relatives were from the same continent, Tyrannotitan and Mapusaurus, and was also closely related to Carcharodontosaurus in Africa. It was a distant relative of Allosaurus from the Jurassic period. It had a massive skull, a long tail for extra balance to help support its massive head, fairly long and strong arms with three clawed fingers, and powerful back legs with three sharp talons on their toes. Most people speculate, considering the length and musculature of its legs, that Giganotosaurus could run even 30km/h. It had over 76 8-inch (20 centimeters), blade-like teeth that were built for slashing and bleeding out prey.
Casts of Giganotosaurus and the contemporary sauropod Limaysaurus, Hungarian Natural History Museum
In 2005 Francois Terrier e.a. estimated that the bite force of Giganotosaurus was three times less than that of Tyrannosaurus and that the lower jaws were optimized for inflicting bleeding wounds; the point of the mandibula was reinforced to this purpose with a "chin" and broadened to handle smaller prey. The killing method of Giganotosaurus is killing by slicing through flesh and letting its prey bleed to death. An extremely brutal and unethical, but effective method. Titanosaur fossils, belonging to Andesaurus and Limaysaurus, have been recovered near the remains of Giganotosaurus, leading to speculation that these carnivores may have preyed on the giant herbivores. Fossils of the related carcharodontosaurid Mapusaurus grouped closely together may indicate pack hunting, a behavior that could possibly extend to Giganotosaurus itself.
In a study from 2021, A. J. Rowe and Snively estimated a bite force of 24,977 Newtons (~2.5 metric tons) for Giganotosaurus.
The original fossils of Giganotosaurus remain at the Carmen Funes Museum in Neuquen, Argentina, but replicas are common in other places, including the Australian Museum in Sydney.
Paleoenvironment[]
Restoration of Giganotosaurus with contemporary dinosaurs
Giganotosaurus lived in Argentina during the Late Cretaceous, and was one of the dominant apex predators in it's ecosystem. Studies on the oxygen isotope patterns in the fossils closely matched the patterns recorded in Tyrannosaurus. This tells us that the thermoregulation in dinosaurs was between mammals and reptiles. Giganotosaurus would have grown up fast, and, in tern, had a metabolism of about 8 tons. Giganotosaurus had an approximate run speed of 14 m/s (50 km/h, 31 mph).
Giganotosaurus lived in the Candeleros Formation, deposited about 98 to 94 million years ago. Giganotosaurus lived with the following: sauropods Andesaurus, Limaysaurus, Argentinosaurus, Nopcsaspondylus, theropods Ekrixinatosaurus, Buitreraptor and Alnashetri. Miscellaneous reptiles include: the crocodyliform Araripesuchus, sphenodontians, snakes and turtles like Prochelidella. Other vertebrates include: cladotherian mammals, one genus of pipoid frog, ceratodontiform fishes and several ichnogenera suggest that several ornithopods and pterosaurs also inhabited the region.
Notable Specimens[]
- MUCPv-Ch1 is the holotype of Giganotosaurus, discovered in 1995, known from a partial skull, cervical, dorsal, sacral, and caudal vertebrae, ribs, hip bones, left and right femurs, left tibia nd fibula, and scapulae. Estimated at 12 - 12.7 m long.
- MMCh-PV-95 is a large Giganotosaurus specimen, estimated to be 12 - 13 m long. Known from a dentary.
JPInstitute.com Description[]
Giganotosaurus was one big carnivore. It may have been the biggest one of all, even bigger than T. rex. It lived in South America at a time when there were still large sauropods for it to eat. It had a very strong body and a mouth full of teeth like steak knives. Just its head alone was almost 6 feet (2 m) long.
A recent discovery in Argentina suggests that Giganotosaurus may have been as large as 46 feet (15 m). What is interesting is that there is another dinosaur found in North Africa, called Carcharodontosaurus that is almost identical - in fact, it may be the same genus. Since South America and Africa were still connected back then, it is possible they are very close relations.
Like T. rex, this dinosaur hunted in warm and swampy areas. Some of the sauropods of that time had armor on their backs in order to protect them from an attack from above and that kind of attack could only have come from a predator as large as Giganotosaurus.
Dinosaur Field Guide Description[]
Giganotosaurus (*giant southern lizard") is currently the largest known meat-eating dinosaur ever. For many years Tyrannosaurus held that record (although bits and pieces of Carcharodontosaurus and Spinosaurus showed that they were as large as any individual T. rex). Then, in 1995, paleontologists Rodolfo Coria and Leonardo Salgado reported the discovery of a new meat-eater bigger than any tyrant dinosaur. They named this dinosaur Giganotosaurus, Bone for bone, it was larger than the largest skeleton of T. rex ever found! The skull alone was 6 feet (1.8 m) long! What's more, a lower jaw-bone was later found from an individual even bigger than the first one with a skull perhaps 6.5 feet (2 m) long. Clearly, Giganotosaurus was a gigantic dinosaur. When Giganotosaurus was alive, the most common plant-eaters in South America were the titanosaur sauropods. While a single Giganotosaurus could kill a young titanosaur, it would take many Giganotosaurus to bring down a giant adult. At present, there is no evidence that Giganotosaurus hunted in groups, but a recent discovery from slightly younger rocks shows that the as-yet-unnamed descendant of Giganotosaurus may have Lived in packs.
Fun Facts[]
A cast of the skeleton of Giganotosaurus is on display at the Academy of Natural Sciences in Philadelphia, and another will be put on display at the Fernbank Museum in Atlanta in the near future.
Trivia[]
Giganotosaurus might be the dinosaur whose name is most often misspelled and/or mispronounced. People often call it Gigantosaurus (with only one'""') instead of the proper Giganotosaurus, with two. The name Gigantosaurus was actually given to bits and pieces of a British long-necked sauropod dinosaur back in 1869,
Gallery[]
Appearance in other media[]
Jurassic Park[]
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Read more Giganotosaurus on Jurassic Park Wiki |
The Land Before Time[]
Links[]
References[]
- https://www.nature.com/articles/377224a0
- https://www.npr.org/2015/06/14/414286692/bankrolling-a-dinosaur-dig-and-unearthing-a-giant-the-giganotosaurus
- https://www.tandfonline.com/doi/abs/10.1080/02724634.1994.10011592
- https://www.tandfonline.com/doi/abs/10.1671/0272-4634%282002%29022%5B0802%3ATBOGCD%5D2.0.CO%3B2
- https://www.smithsonianmag.com/science-nature/battle-of-the-giant-theropods-37868070/
- https://www.jstor.org/stable/3979427?origin=crossref
- https://ui.adsabs.harvard.edu/abs/1996Sci...272..971C/abstract
- https://onlinelibrary.wiley.com/doi/abs/10.2307/4018414
- https://www.researchgate.net/publication/40662857_New_specimen_of_Giganotosaurus_carolinii_Coria_Salgado_1995_supports_it_as_the_largest_theropod_ever_found
- https://dinoweb.ucoz.ru/_fr/4/A_new_method_to.pdf
- http://www.miketaylor.org.uk/tmp/papers/Mazzetta-et-al_04_SA-dino-body-size.pdf
- https://www.tandfonline.com/doi/abs/10.1671/0272-4634%282007%2927%5B108%3AMTIBTY%5D2.0.CO%3B2
- https://www.tandfonline.com/doi/full/10.1080/14772019.2011.630927
- https://www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013
- https://ui.adsabs.harvard.edu/abs/2005NW.....92..226N/abstract
- https://web.archive.org/web/20160930130941/http://news.nationalgeographic.com/news/2006/04/0417_060417_large_dino.html
- https://www.app.pan.pl/article/item/app46-193.html
- https://www.investigacionyciencia.es/revistas/investigacion-y-ciencia/termes-prehistricos-atrapados-en-mbar-215/dinosaurios-carnvoros-de-sudamrica-6530
- https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0157793https://www.pure.ed.ac.uk/ws/files/8232966/PDF_BrusatteSereno2008AllosauroidPhylogeny.pdf
- https://anatomypubs.onlinelibrary.wiley.com/doi/full/10.1002/ar.24602?af=R
- https://www.thecodontia.com/theropods
- https://twitter.com/DanPalaeon1/status/1552415964565622784/photo/1
- https://www.thecodontia.com/blog/i-was-wrong-about-giganotosaurus-not-clickbait
- ↑ Coria RA & Salgado L (1995). A new giant carnivorous dinosaur from the Cretaceous of Patagonia. Nature 377: 225-226
- ↑ 2.0 2.1 Coria RA & Currie PJ. 2006: A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina. Geodiversitas: Vol. 28, #1, pp. 71-118
- ↑ Seebacher, F. 2001. A new method to calculate allometric length-mass relationships of dinosaurs. Journal of Vertebrate Paleontology 21(1): 51–60.
- ↑ Mortimer, M. (2004), "Carnosauria", The Theropod Database, viewed August 14, 2008.
- ↑ Calvo, J.O., and Coria, R.A. (1998) "New specimen of Giganotosaurus carolinii (Coria & Salgado, 1995), supports it as the as the largest theropod ever found." Gaia, 15: 117–122.
- ↑ Brochu, C.R. 2003. Osteology of Tyrannosaurus rex: insights from a nearly complete skeleton and high-resolution computed tomographic analysis of the skull. Memoirs of the Society of Vertebrate Paleontology. 7: 1-138.
- ↑ Template:Cite journal
- ↑ Giganotosaurus By Sean Henahan, Access Excellence
- ↑ Template:Cite journal