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

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

. The

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...

''Futalognkosaurus'' lived approximately 87 million years ago in the

Portezuelo Formation The Portezuelo Formation is a geologic formation of Late Cretaceous ( Late Turonian to Early Coniacian) age, outcropping in the Mendoza, Río Negro and Neuquén provinces of Argentina.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 ...

stage of the late

Cretaceous Period The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of t ...

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

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and g ...

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 (; arn, Nehuenken) 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 river ...

province of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the List of South American countries by area, second-largest ...

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

Unenlagia ''Unenlagia'' (meaning "half-bird" in Latinized Mapudungun) is a genus of dromaeosaurid theropod dinosaur that lived in South America during the Late Cretaceous period. The genus ''Unenlagia'' has been assigned two species: ''U. comahuensis'', ...

'', 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 thr colurse of the river around it, lasting long enough for fish and bivalves to live in ir, and eventually creating an oxbow lake behind. The genus name is derived from the local indigenous language

Mapudungun Mapuche (, Mapuche & Spanish: , or Mapudungun; from ' 'land' and ' 'speak, speech') is an Araucanian language related to Huilliche spoken in south-central Chile and west-central Argentina by the Mapuche people (from ''mapu'' 'land' and ''che ...

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 is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

of the

type species In 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 species that contains the biological type specim ...

, ''Futalognkosaurus dukei'', was originally estimated at in length. In 2008 this was downsized to . In 2012

Holtz Holtz is the surname of: * Alexander Holtz (born 2002), Swedish ice hockey player * Andrew Holtz, American journalist * Carl Holtz (1920–2006), American oarsman and farmer * Daniel Holtz, a fictional character on the TV series ''Angel'' * Eric ...

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 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: *Paul (given name), a given name (includes a list of people with that name) * Paul (surname), a list of people People Christianity *Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Chri ...

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 .

Classification

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

Titanosauridae 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'' ...

(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'' ...

, depending on the definitions being used), and most closely related to ''

Mendozasaurus ''Mendozasaurus'' is a genus of titanosaurian sauropod dinosaur. It was a member of Titanosauria, which were massive sauropods that were common on the southern landmasses during the Cretaceous. It is represented by several partial skeletons fro ...

''. They defined a new

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

for the group containing both ''Futalognkosaurus'' and ''Mendozasaurus'', their common ancestor, and all descendants, which they named the

Lognkosauria Lognkosauria is a clade of giant long-necked sauropod dinosaurs within the clade Titanosauria. It includes some of the largest and heaviest dinosaurs known. Description Lognkosaurians can be distinguished from other titanosaurs by the wide and u ...

. The authors found ''

Malawisaurus ''Malawisaurus'' (meaning "Malawi lizard") is an extinct genus of titanosaurian sauropod dinosaur. It is known from the Dinosaur Beds of northern Malawi, which probably date to the Aptian stage of the Early Cretaceous. The type species is ''M. di ...

'' to be the sister group of this new clade. Another, much later member of Lognkosauria is the colossal ''

Puertasaurus ''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, Ar ...

'', which may be the biggest dinosaur so far known. Besides ''Futalognkosaurus'', other

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is '' flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. ...

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

'' 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 differen ...

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

The following

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

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 sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thr ...

, 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 The National Museum of Brazil ( pt, Museu Nacional) is the oldest scientific institution of Brazil. It is located in the city of Rio de Janeiro, where it is installed in the Paço de São Cristóvão (Saint Christopher's Palace), which is i ...

.
Illustration of ''Futalognkosaurus'' by paleoartist Julius T. Csotonyi
{{Portal bar, Dinosaurs, Paleontology, Cretaceous Lithostrotians Coniacian life Late Cretaceous dinosaurs of South America Cretaceous Argentina Fossils of Argentina Portezuelo Formation Fossil taxa described in 2007