''Loncosaurus'' (meaning uncertain; either

Araucanian The Mapuche ( (Mapuche & Spanish: )) are a group of indigenous inhabitants of south-central Chile and southwestern Argentina, including parts of Patagonia. The collective term refers to a wide-ranging ethnicity composed of various groups who sha ...

"chief" or

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

"lance" "lizard"Dinosaur Translation Guide L
) is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 world ...

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

Upper 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 ...

of Provincia de Santa Cruz,

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 second-largest country in South America after Brazil, th ...

. The type (and only known)

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

is ''Loncosaurus argentinus'', described by the famous

Argentinian Argentines (mistakenly translated Argentineans in the past; in Spanish (masculine) or ( feminine)) are people identified with the country of Argentina. This connection may be residential, legal, historical or cultural. For most Argentines, ...

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Florentino Ameghino Florentino Ameghino (born Giovanni Battista Fiorino Giuseppe Ameghino September 19, 1853 – August 6, 1911) was an Argentine naturalist, paleontologist, anthropologist and zoologist, whose fossil discoveries on the Argentine Pampas, especially ...

, but is considered a

dubious Doubt is a mental state in which the mind remains suspended between two or more contradictory propositions, unable to be certain of any of them. Doubt on an emotional level is indecision between belief and disbelief. It may involve uncertainty, ...

name. Details on this animal are often contradictory, befitting a genus that was long confused for a

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

. Teeth attributed to ''cf.'' " Carnosaurus" may have actually belonged to ''Loncosaurus''.Olshevsky, DML 1999. http://dml.cmnh.org/1999Nov/msg00507.html

History

The holotype

femur 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

tooth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

were discovered by

Carlos Ameghino Carlos Ciriaco Ameghino (16 June 1865 – 12 April 1936) was an Argentine paleontologist and explorer who accompanied his brother Florentino Ameghino throughout Argentina searching for fossils. Scientific career Carlos Ameghino was educated ...

, Florentino's brother, between 1887 and 1898. Ameghino named this dinosaur in 1899Ameghino, F. 1898. Sinopsis geológico-paleontológica. ''Segundo censo de la República Argentina''. Folia:Buenos Aires, 1:112-255. panish/ref>Norman, D.B., and Weishampel, D.B. 1990. Iguanodontidae and related ornithopods. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). ''The Dinosauria''. University of California Press:Berkeley, 510-533. Norman, D.B. 2004. Basal Iguanodontia. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). ''The Dinosauria'' (second edition). University of California Press:Berkeley, 413-437. George Olshevsky'
Dinosaur Genera List
/ref> Ameghino, F. 1899. Nota preliminar sobre el ''Loncosaurus argentinus'', un representante de la familia Megalosauridae de la República Argentina. ''Anales de la Sociedad Cientifica Argentina'' 49:61-62. panish/ref>Coria, R.A., and Salgado, L. 1996. ''Loncosaurus argentinus'' Ameghino, 1899 (Ornithischia, Ornithopoda): a revised description with comments on its phylogenetic relationships. ''

Ameghiniana ''Ameghiniana'' is a peer-reviewed scientific journal covering palaeontology published by the Asociación Paleontológica Argentina. It is named after the 19th century Italian Argentine palaeontologist Florentino Ameghino. The discovery of many di ...

'' 33(4):373-376.Glut, D.F. (1997). ''Dinosaurs: The Encyclopedia''. Mcfarland & Company, Inc., xi-1076. Coria, R.A. 1999. Ornithopod dinosaurs from the Neuquén Group, Patagonia, Argentina: phylogeny and biostratigraphy. In Tomida, Y., Rich, T.H., and Vickers-Rich, P. (eds.) ''Proceedings of the Second Gondwanan Dinosaur Symposium, National Science Museum Monographs'' 15:47-60.The Paleobiology Database
from a

proximal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

femur (MACN-1629) and tooth found near Rio Sehuen, Santa Cruz, in the

Cardiel Formation The Cardiel Formation is a Maastrichtian geologic formation of the Austral Basin in Santa Cruz Province, Argentina. The formation comprises sandstones and conglomerates with abundant tuff beds.Pérez Panera, 2010, p.45 The formation is overlain ...

(Upper Cretaceous). Either way, he thought the remains belonged to a "

megalosaurid Megalosauridae is a monophyletic family of carnivorous theropod dinosaurs within the group Megalosauroidea. Appearing in the Middle Jurassic, megalosaurids were among the first major radiation of large theropod dinosaurs. They were a relative ...

" dinosaur, a

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

, which

Friedrich von Huene Friedrich von Huene, born Friedrich Richard von Hoinigen, (March 22, 1875 – April 4, 1969) was a German paleontologist who renamed more dinosaurs in the early 20th century than anyone else in Europe. He also made key contributions about v ...

agreed with.von Huene, F. 1909. Skizze zu einer Systematik und Stammesgeschichte der Dinosaurier. ''Centralblatt für Mineralogie, Geologie und Paläontologie'' 1909:12-22.

erman Erman Rašiti may refer to: Given name * Erman Bulucu (born 1989), Turkish footballer * Erman Eltemur (born 1993), Turkish karateka * Erman Güraçar (born 1974), Turkish footballer * Erman Kılıç (born 1983), Turkish footballer * Erman Kunter (b ...

/ref> Upon further review, von Zittel assigned it to the

Coeluridae Coeluridae is a historically unnatural group of generally small, carnivorous dinosaurs from the late Jurassic Period. For many years, any small Jurassic or Cretaceous theropod that did not belong to one of the more specialized families recognize ...

,von Zittel, K.A.. 1911. ''Grundzüge der Paläontologie (Paläozoologie).'' II. Abteilung. Vertebrata. Druck und Verlag von R. Oldenbourg:München, 1-598.

/ref> recognized today as a "

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...

" for small

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

dinosaurs. The carnivore tooth helped this misidentification take hold. It was ignored for decades until

Ralph Molnar Ralph E. Molnar is a paleontologist who had been Curator of Mammals at the Queensland Museum and more recently associated with the Museum of Northern Arizona. He is also a research associate at the Texas natural Science Centre. He co-authored descr ...

reassessed it.Molnar, R.E. 1980. Australian late Mesozoic continental tetrapods: some implications. ''Mémoires de la Société Géologique de France, Nouvelle Série'' 139:131-143. He found that the tooth did not belong to the same animal as the femur and removed it from the type, and suggested that the femur belonged to a

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 ...

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 tu ...

. Professional opinion has not changed much since then, although based on size, it appears more likely to be an

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 ...

than a hypsilophodont. Reviews either put it at Ornithopoda ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' or Iguanodontia. Oddly, a semipopular reference reassigned it to ''

Genyodectes ''Genyodectes'' ("jaw bite", from the Ancient Greek, Greek words ''genys'' ("jaw") and ''dektes'' ("bite")) is a genus of ceratosaurian theropod dinosaur from the Lower Cretaceous (Aptian) of South America. The holotype material (MLP 26–39, Mus ...

'' without comment,Lessem, D., and Glut, D.F. (1993). ''The Dinosaur Society Dinosaur Encyclopedia''. Random House, Inc.:New York, 533 p. a view which has not been followed since.

Paleobiology

Coria estimates the size of the ''Loncosaurus'' type individual at about 5 m (16.4 feet) long. As a small to medium-sized ornithopod, it would have been an agile

bipedal Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' ...

herbivore 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 mouthpart ...

References

{{Taxonbar, from=Q871931 Ornithopods Late Cretaceous dinosaurs of South America Cretaceous Argentina Fossils of Argentina Nomina dubia Taxa named by Florentino Ameghino Ornithischian genera Fossil taxa described in 1899