''Gasparinisaura'' (meaning "Gasparini's 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 ...

of herbivorous

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous w ...

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 ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

. The first fossils of ''Gasparinisaura'' were found in 1992 near

Cinco Saltos Cinco Saltos is a city in the provinces of Argentina, province of Río Negro Province, Río Negro, Argentina, located on the eastern side of the valley of the Neuquén River, near the Pellegrini Lake, about from northwest of Neuquén and from All ...

Río Negro Province Río Negro (, ''Black River'') is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean. Its capi ...

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 ...

. 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 ...

, ''Gasparinisaura cincosaltensis'', was named and described in 1996 by

Rodolfo Coria Rodolfo Aníbal Coria (born in Neuquén June 1, 1959), is an Argentine paleontologist. He is best known for having directed the field study and co-naming of '' Argentinosaurus'' (possibly the world's largest land animal ever) in 1993, and ''Giga ...

and

Leonardo Salgado Leonardo Salgado is an Argentinean palaeontologist with a special interest in dinosaurs of the Cretaceous period and other investigations of the palaeobiology of fossil bearing geological formations. Salgado is the leading or coauthor of several ta ...

. The generic name honors Argentine palaeontologist

Zulma Brandoni de Gasparini Zulma Nélida Brandoni de Gasparini (born 15 May 1944) is an Argentinian paleontologist and zoologist. She is known for discovering the fossils of the dinosaur '' Gasparinisaura'', which was named after her. Work Born in the city of La Plata, ...

. The specific name refers to Cinco Saltos.Coria, R. A., and L. Salgado. (1996). "A basal iguanodontian (Ornithischia: Ornithopoda) from the Late Cretaceous of South America". ''Journal of Vertebrate Paleontology'' 16: 445–457

Discovery

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 ...

, MUCPv-208, was uncovered in a layer of the

Anacleto Formation The Anacleto Formation is a geologic formation with outcrops in the Argentine Patagonian provinces of Mendoza, Río Negro, and Neuquén. It is the youngest formation within the Neuquén Group and belongs to the Río Colorado Subgroup. Formerl ...

, dating from the early

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...

, about 83 million years old. It consists of a partial skeleton with skull, lacking much of the vertebral column. The

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). O ...

is MUCPv-212, a tail with lower hindlimb elements. In 1997, three additional specimens were described: MUCPv 213, a partial skeleton with skull; MCSPv 111, a postcranial skeleton; and MCSPv 112, a skull with hindlimbs and pelvis. The three later specimens represent juvenile individuals. In 2008,

gastroliths A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In othe ...

present with all three juvenile specimens were described.Ignacio A. Cerda, 2008, "Gastroliths in an ornithopod dinosaur", ''Acta Palaeontologica Polonica'' 53(2): 351-355

Description

''Gasparinisaura'' was a small bipedal herbivore. In 2010, Gregory S. Paul estimated the length at and the weight at .Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 278 ''Gasparinisaura'' had a rounded head that was moderately elongated. The eye sockets were very large and placed in a high position. The rather long back of the head was pendant. The

jugal The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy ...

had a front branch that was thin and wedged between the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. T ...

and the lacrimal; the back of the jugal was high and broad. The

quadratojugal The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians. Anatomy and function In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and ...

had a long ascending process touching the

squamosal The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...

, a basal trait. The jaw joints were low. There were about twelve, rather large, maxillary or dentary teeth in each upper or lower jaw. The forelimbs were lightly built. The ilium was short and low, the pubis thin. The hindlimbs were relatively long and powerful, with a short

thighbone The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

and a long lower leg. The foot was long and the first

metatarsal The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the me ...

was reduced to a splint, a derived trait. The tail featured low plate-like triangular chevrons that were expanded towards the back, which is unique in the

Euornithopoda Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...

. The gastroliths discovered formed clusters of up to hundred-forty rounded and polished stones in the abdomen with an average stone diameter of about eight millimetres. Representing about 0.3% of total body weight, they were voluminous enough to function as a gastric mill, a function sometimes denied for

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', ' lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their ...

gastroliths because of their insufficient relative mass, being an order of magnitude lower.

Classification

''Gasparinisaurus'' was originally considered by the describers to have been a basal

iguanodont Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include ''Camptosaurus'', ''Dryosaurus'', ''Iguanodon'', '' Tenontosaurus'', and the hadrosaurids or "duck-bil ...

, the most basal member of the

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 ...

Euiguanodontia Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include ''Camptosaurus'', ''Dryosaurus'', '' Iguanodon'', ''Tenontosaurus'', and the hadrosaurids or "duck- ...

. A phylogenetic analysis included in the description of the Antarctic ornithopod ''

Morrosaurus ''Morrosaurus'' is an extinct genus of herbivorous ornithopod dinosaur member of the Elasmaria, that lived in the late Cretaceous in the Antarctica. The only known species is the type ''Morrosaurus antarcticus''. Discovery In 2002 the Argent ...

'' shows that the latter and ''Gasparinisaura'' are part of Elasmaria, a

of iguanodonts known from South America, Antarctica and maybe Australia. ''Gasparinisaura'' would be the basalmost member of this group.Sebastián Rozadilla, Federico L. Agnolin, Fernando E. Novas, Alexis M. Aranciaga Rolando, Matías J. Motta, Juan M. Lirio & Marcelo P. Isasi, 2016, "A new ornithopod (Dinosauria, Ornithischia) from the Upper Cretaceous of Antarctica and its palaeobiogeographical implications", ''Cretaceous Research'' 57: 311–324
/ref>

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 ...

based in the

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

of Rozadilla ''et al''., 2016:

References

{{Taxonbar, from=Q2704268 Ornithopods Campanian life Late Cretaceous dinosaurs of South America Cretaceous Argentina Fossils of Argentina Anacleto Formation Fossil taxa described in 1996 Taxa named by Rodolfo Coria Ornithischian genera