''Futalognkosaurus'' ( ; meaning "giant chief lizard") is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

titanosaur Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thr ...

ian

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

. The

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

''Futalognkosaurus'' lived approximately 87 million years ago in the Portezuelo Formation, in what is now Argentina, of the

Coniacian The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by ...

stage of the late

Cretaceous Period The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geologi ...

. The fish and fossilized leaf debris on the site, together with other dinosaur remains, suggest a warm tropical climate in

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

during this period.

Discovery

Fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

of ''Futalognkosaurus'' were found in the

Neuquén Neuquén (; ) is the capital city of the Argentine province of Neuquén and of the Confluencia Department, located in the east of the province. It occupies a strip of land west of the confluence of the Limay and Neuquén rivers which form t ...

province of

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

in 2000, and were scientifically described in 2007, alongside sauropods, ''

Megaraptor ''Megaraptor'' () is a genus of large Theropoda, theropod dinosaur that lived during the Turonian and Coniacian ages of the Late Cretaceous. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America. Th ...

'', '' Unenlagia'', iguanodonts, peirosaurids, and pterosaurs. The holotype was found near the margins of a river. The holotype was hypothesised to have been washed into the river after its death. Due to its giant size the carcass likely acted as a barrier, altering the course of the river around it, lasting long enough for fish and bivalves to live in it, and eventually leaving an oxbow lake behind. The genus name is derived from the local indigenous language

Mapudungun Mapuche ( , ; from 'land' and 'people', meaning 'the people of the land') or Mapudungun (from 'land' and 'speak, speech', meaning 'the speech of the land'; also spelled Mapuzugun and Mapudungu) is either a language isolate or member of the s ...

and is pronounced foo-ta-logn-koh-sohr-us: "futa" means "giant" and "lognko" means "chief".Calvo, J.O., Porfiri, J.D., González-Riga, B.J., and Kellner, A.W. (2007)
A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur
. ''Anais da Academia Brasileira de Ciências'', 79(3): 529-4

/ref> It is based on three fossil specimens, yielding an estimated 70% of the skeleton in total. The fossil team described the find as "the most complete giant dinosaur known so far".

Description

The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

of the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, ''Futalognkosaurus dukei'', was originally estimated at in length. In 2008 this was downsized to . In 2012 Holtz estimated it at long and with an approximate weight of 43.5 to 51 tonnes (48-56 short tons).Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'
Supplementary Information
/ref> An estimate by

Gregory S. Paul Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology. He is best known for his work and research on theropoda, theropod dinosaurs and his detailed illustrations, both l ...

in 2016 was that ''Futalognkosaurus'' had a maximum length of and a weight of 50+ tonnes (55 short tons) .Paul, G.S., 2016, ''The Princeton Field Guide to Dinosaurs'', 2nd Edn, p. 233, Princeton University Press In 2016, using equations that estimate body mass based on the circumference of the humerus and femur of quadrupedal animals, it was given an estimated weight of 38.1 tonnes (42 short tons). In 2019,

Paul Paul may refer to: People * Paul (given name), a given name, including a list of people * Paul (surname), a list of people * Paul the Apostle, an apostle who wrote many of the books of the New Testament * Ray Hildebrand, half of the singing duo ...

estimated the weight of the holotype specimen, (MUCPv-323) at 29 tonnes (32 short tons), and later, in 2020, Molina-Pérez and Larramendi estimated its length at , and its weight at 30 tonnes (33 short tons). Its long neck contained 14 vertebrae, and was ove
a meter deep in places
due to its extremely tall neural spines which had a distinctiv
"shark-fin" shape
The hips were also extremely large and bulky, reaching a width of nearly . File:The Real Futalogkosaurus - Nima Sassani.jpg, Restoration File:Futalognkosaurus BW.jpg, Restoration File:Futalognkosaurus Size Comparison.svg, Size comparison

Classification

In their phylogenetic analysis, Calvo and colleagues found ''Futalognkosaurus'' to be a member of the Titanosauridae (or

Lithostrotia Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch ''et al.'' in 2004 as the most recent common ancestor of ''Malawisaurus'' and ''Saltasaurus'' an ...

, depending on the definitions being used), and most closely related to '' Mendozasaurus''. They defined a new

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

for the group containing both ''Futalognkosaurus'' and ''Mendozasaurus'', their common ancestor, and all descendants, which they named the Lognkosauria. The authors found '' Malawisaurus'' to be the sister group of this new clade. Another, much later member of Lognkosauria is the colossal '' Puertasaurus'', which may be the biggest dinosaur so far known. Besides ''Futalognkosaurus'', other

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

was discovered in the Futalognko site, including two further undescribed sauropod taxa, specimens of ''

'', '' Unenlagia'' and some

pleurodira The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differ ...

turtle Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...

s. The following

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

shows the results of an analysis by Calvo ''et al.'' in 2007, where they placed ''Futalognkosaurus'' within the group

Titanosauria Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of Sauropoda, sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with tax ...

, more precisely the clade Lognkosauria:

References

External links

Dinosaur Mailing List entry which discusses the genus

Fósiles hallados en el Centro Paleontológico Lago Barreales
- contains images of ''Futalognkosaurus'' (in Spanish)
BBC Report
of Monday, 15 October 2007 - includes a photo of some of the dinosaur's bones, attributed to

National Museum of Brazil National may refer to: Common uses * Nation or country ** Nationality – a ''national'' is a person who is subject to a nation, regardless of whether the person has full rights as a citizen Places in the United States * National, Maryland, ...

.
Illustration of ''Futalognkosaurus'' by paleoartist Julius T. Csotonyi
{{Portal bar, Dinosaurs, Paleontology Lognkosauria Dinosaur genera Coniacian dinosaurs Portezuelo Formation Fossil taxa described in 2007 Taxa named by Alexander Kellner Dinosaurs of Argentina