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

of herbivorous

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

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 ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...

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

Cinco Saltos Cinco Saltos is a city in the province of Río Negro, Argentina, located on the eastern side of the valley of the Neuquén River, near the Pellegrini Lake, about northwest of Neuquén and from Allen. It has 19,819 inhabitants as per the . T ...

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 cap ...

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 ...

. 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 ...

, ''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 '' Gigan ...

and

Leonardo Salgado Leonardo Salgado is an Argentine palaeontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossi ...

. The generic name honors Argentine palaeontologist

Zulma Brandoni de Gasparini Zulma Nélida Brandoni de Gasparini (born 15 May 1944) is an Argentine 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, Arg ...

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

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 (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 ...

, MUCPv-208, was uncovered in 1992 in a layer of the

Anacleto Formation The Anacleto Formation is a geologic formation with outcrops in the Argentina, Argentine Patagonian provinces of Mendoza Province, Mendoza, Río Negro Province, Río Negro, and Neuquén Province, Neuquén. It is the youngest formation within the ...

, 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. Campa ...

, 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 (biology), isotype ...

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 oth ...

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 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 ...

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 In vertebrates, the maxilla (: maxillae ) 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. The two maxil ...

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 ancestra ...

, 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 (; : femurs or femora ), or thigh bone is the only bone in the thigh — the region of the lower limb between the hip and the knee. In many four-legged animals the femur is the upper bone of the hindleg. The top of the femur fits i ...

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

metatarsal The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

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 (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

. 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 b ...

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

hypsilophodont Hypsilophodontidae (or Hypsilophodontia) is a traditionally used family of ornithopod dinosaurs, generally considered invalid today. It historically included many small bodied bipedal neornithischian taxa from around the world, and spanning from ...

, the most basal member of the

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 ...

ornithopoda Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

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

Morrosaurus ''Morrosaurus'' is an extinct genus of herbivorous elasmarian dinosaur that lived in the late Cretaceous in Antarctica. The only known species is the type ''Morrosaurus antarcticus''. Discovery In 2002, the Argentine paleontologist Fernando ...

'' shows that the latter and ''Gasparinisaura'' are part of

Elasmaria Elasmaria is a clade of Ornithopoda, ornithopods known from Cretaceous deposits in the former Gondwana (South America, Antarctica, Australia, and possibly Africa) that contains many bipedal ornithopods that were previously considered Hypsilophodo ...

, a

of hypsilophodonts 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 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 ...

based in the

phylogenetic analysis In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

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

References

{{Taxonbar, from=Q2704268 Elasmaria Dinosaur genera Campanian dinosaurs Anacleto Formation Fossil taxa described in 1996 Taxa named by Rodolfo Coria Dinosaurs of Argentina