''Zupaysaurus'' (; "ZOO-pay-SAWR-us") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

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 early

theropod Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...

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 ...

living during the

Norian The Norian is a division of the Triassic geological period, Period. It has the rank of an age (geology), age (geochronology) or stage (stratigraphy), stage (chronostratigraphy). It lasted from ~227.3 to Mya (unit), million years ago. It was prec ...

stage of the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...

in what is now

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 ...

. Fossils of the dinosaur were found in the

Los Colorados Formation The Los Colorados Formation is a sedimentary geological formation, rock formation of the Ischigualasto-Villa Unión Basin, found in the provinces of San Juan Province, Argentina, San Juan and La Rioja Province (Argentina), La Rioja in Argentina. ...

of the Ischigualasto-Villa Unión Basin in northwestern Argentina. Although a full skeleton has not yet been discovered, ''Zupaysaurus'' can be considered a

biped Bipedalism is a form of terrestrial locomotion where an animal moves by means of its two rear (or lower) 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'' ' ...

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

, up to long. It may have had two parallel crests running the length of its snout.

Discovery

Discovered in May 1997 by Santiago Reuil ("Vultur"), part of the crew of Guillermo Rougier, it was later described by Arcucci and Coria and published in 2003. The name ''Zupaysaurus'' is composed of the Quechua word ''supay'' meaning "devil" and the

Greek Greek may refer to: 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 of all kno ...

word ' () meaning "lizard"; thus "devil lizard". In Incan mythology, '' supay'' was both the god of death and ruler of the '' ukhu pacha'', the Incan underworld. 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 ...

was named ''Z. rougieri'' in the honor of Guillermo Rougier, the scientist who led the expedition which discovered and collected 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 ...

(original specimen) PULR-076. ''Zupaysaurus'' was first described and named in the scientific journal '' Ameghiniana'' by

Argentine Argentines, Argentinians or Argentineans are people from Argentina. This connection may be residential, legal, historical, or cultural. For most Argentines, several (or all) of these connections exist and are collectively the source of their ...

paleontologist 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 fossils as a means to classify organisms, measure geolo ...

s Andrea Arcucci and Rodolfo Coria in 2003.

Description

''Zupaysaurus'' was a medium-sized theropod. An adult

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

, measured approximately in length, suggesting a body length of approximately from its snout to the tip of its tail. 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 ...

gave a length of 6 meters (20 ft) and a weight of 250 kg (550 lbs). In 2016 it was given a much smaller size of 4.2 meters (14 ft) and 70 kg (154 lbs). Like all theropods, ''Zupaysaurus'' walked only on its hindlegs, leaving its forelimbs free to grasp its

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

. The length of the neck bones recovered suggests that this genus has a rather long neck. Like the coelophysoids, ''Zupaysaurus'' has a kink in its snout, between the

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...

ry and

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 ...

ry bones of the upper jaw. It is estimated that ''Zupaysaurus'' had 24 teeth and an intermandibular hinge is present in the lower jaw.Arcucci, A.B. & Coria R.A. 2003. A new Triassic carnivorous dinosaur from Argentina. '' Ameghiniana'' 40(2):217-228. Only one specimen of ''Zupaysaurus'' is known to science. The

specimen was designated PULR-076, which consists of a nearly complete skull which was very well preserved, the right

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder m ...

girdle, the lower right leg and

ankle The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The ...

, and twelve

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e from the neck, back, and hips. Additional material of a smaller individual found at the same site may or may not belong to ''Zupaysaurus''. As ''Zupaysaurus'' was originally described, the head bore two thin parallel crests on top of the skull, similar to theropods like ''

Dilophosaurus ''Dilophosaurus'' ( ) is a genus of theropod dinosaurs that lived in what is now North America during the Early Jurassic, about 186 million years ago. Three skeletons were discovered in northern Arizona in 1940, and the two best preserv ...

'' and '' Coelophysis kayentakatae''. These crests are thought to have been formed by the

nasal Nasal is an adjective referring to the nose, part of human or animal anatomy. It may also be shorthand for the following uses in combination: * With reference to the human nose: ** Nasal administration, a method of pharmaceutical drug delivery * ...

bones solely, unlike those of many other theropods which also incorporated the lacrimal bones. Crests on the skull were pervasive among theropods and may have been used for communicative purposes such as species or gender recognition.Currie, P.J. & Zhao X. 1993. A new carnosaur (Dinosauria, Theropoda) from the Jurassic of Xinjiang, People's Republic of China. ''Canadian Journal of Earth Sciences'' 30: 2037-2081. However, more recent analysis of the skull has cast doubt on the presence of these crests in ''Zupaysaurus''. An unpublished abstract presented at a recent conference indicated the structures initially identified as crests were in fact the lacrimal bones displaced upwards during the process of

fossil 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 preserve ...

ization.Ezcurra, M.D. & Novas, F.E. 2005. Phylogenetic relationships of the Triassic theropod ''Zupaysaurus rougieri'' from NW Argentina. Presented in August 2005 during th
II Latin American Congress of Vertebrate Paleontology
in

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. This analysis will be published in peer-reviewed print form later in 2006. A summary of the talk can be see
here
Other cranial ornamentation included a rugose laterally-projecting lacrimal ridge on the top of the skull.

A diagnosis is a statement of the anatomical features of an organism (or group) that collectively distinguish it from all other organisms. Some, but not all, of the features in a diagnosis are also autapomorphies. An autapomorphy is a distinctive anatomical feature that is unique to a given organism or group. According to Ezcurra (2006) and Ezcurra and Novas (2006), ''Zupaysaurus'' can be distinguished based on the following characteristics: the maxillary fenestra is within the antorbital fossa (according to Ezcurra, 2006), the rostral process of the lacrimal is ventrally bowed (according to Ezcurra, 2006), the ventral process of 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 ...

is kinked (according to Ezcurra, 2006), wide contact between squamosal and

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 ...

(according to Ezcurra, 2006). The maxillary-jugal ventral margin describes an obtuse angle in lateral view (according to Ezcurra and Novas, 2006), a notch on the dorsal margin of the ascending process of the maxilla, relating to horizontal ramus of the lacrimal is rostrally tapering onto the forked caudal tip of the ascending process of the

; (according to Ezcurra and Novas, 2006), a lacrimal with a highly pneumatized antorbital recess (according to Ezcurra and Novas, 2006), a short and square-shaped retroarticular process of the

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

(according to Ezcurra and Novas, 2006), the cnemial crest is poorly developed (according to Ezcurra and Novas, 2006).

Classification

''Zupaysaurus'' was classified as the earliest known

tetanuran Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, and coelurosaurs (which includes tyrannosauroids, ornithomimosaurs, compsognathids and maniraptoran ...

theropod due to several features of its skull, dentition, and hindlimb. However, several features typical of more basal theropods were also noted by the original authors. Analyses by Carano (2005), Tykoski (2005), and Ezcurra and Novas (2005) have classified ''Zupaysaurus'' as a coelophysoid related to ''

Segisaurus ''Segisaurus'' (meaning "Tsegi Canyon lizard") is a genus of small coelophysid theropod dinosaur, that measured approximately 1 metre (3.3 feet) in length. The only known specimen was discovered in early Jurassic strata in Tsegi Canyon, Arizona, ...

'' and probably '' Liliensternus'', though more basal than ''

Coelophysis ''Coelophysis'' ( Traditional English pronunciation of Latin, traditionally; or , as heard more commonly in recent decades) is a genus of coelophysid Theropoda, theropod dinosaur that lived Approximation, approximately 215 to 201.4 million y ...

''.Carrano, M.T., Hutchinson, J.R., & Sampson, S.D. 2005. New information on ''Segisaurus halli'', a small theropod dinosaur from the Early Jurassic of Arizona. ''Journal of Vertebrate Paleontology'' 25(4): 835-849. Yates (2006) found ''Zupaysaurus'' to form a group with ''Dilophosaurus'' and '' Dracovenator'', placing it in a monophyletic Dilophosauridae.Yates, A.M., 2006 (for 2005). "A new theropod dinosaur from the Early Jurassic of South Africa and its implications for the early evolution of theropods." ''Palaeontologia Africana'', 41: 105-122. But later studies found ''Zupaysaurus'' to be a sister taxon sister to a clade containing dilophosaurids, ceratosaurs and tetanurans.Nesbitt, S. J., Smith, N. D., Irmis, R. B., Turner, A. H., Downs, A., & M. A. Norell. 2009. A complete skeleton of a Late Triassic saurischian and the early evolution of dinosaurs. Science 326:1530-1533. Below is a

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 on the phylogenetic analysis conducted by Sues et al. in 2011, showing the relationships of ''Zupaysaurus'':Hans-Dieter Sues, Sterling J. Nesbitt, David S. Berman and Amy C. Henrici (2011). "A late-surviving basal theropod dinosaur from the latest Triassic of North America". Proceedings of the Royal Society B 278 (1723): 3459–3464

Paleoecology

''Zupaysaurus'' was discovered in red siliciclastic sediments at the "Quebrada de los Jachaleros" locality within the

of the

La Rioja La Rioja () is an autonomous communities in Spain, autonomous community and provinces of Spain, province in Spain, in the north of the Iberian Peninsula. Its capital is Logroño. Other List of municipalities in La Rioja, cities and towns in the ...

province in Argentina. This formation has been shown by magnetostratigraphy to date to the

stage of the

period, approximately 228 to 208 million years ago.Weishampel, D.B., Barrett, P.M., Coria, R.A., Le Loueff, J., Xu X., Zhao X., Sahni, A., Gomani, E.M.P., & Noto, C.R. 2004. Dinosaur distribution. In: Weishampel, D.B., Dodson, P., & Osmólska, H. (Eds.). ''The Dinosauria'' (2nd Edition). Berkeley: University of California Press. Pp. 517-606. but has also been assigned to the slightly younger

Rhaetian The Rhaetian is the latest age (geology), age of the Triassic period (geology), Period (in geochronology) or the uppermost stage (stratigraphy), stage of the Triassic system (stratigraphy), System (in chronostratigraphy). It was preceded by the N ...

stage, which was approximately 208 to 201 million years ago.Heckert, A.B. & Lucas, S.G. 1998. Global correlation of the Triassic theropod record. ''Gaia'' 15: 63-74. ot printed until 2000/ref> Both specimens assigned to this genus are housed in the collection of the National University of La Rioja in

La Rioja, Argentina La Rioja ( local pronunciation ), founded as City of All Saints of New Rioja (''in spanish: Ciudad de Todos los Santos de Nueva Rioja''), is the capital and largest city of La Rioja Province, Argentina, located in the east of the province. The ...

. The

was interpreted as an ancient floodplain and it was home to several types of early

sauropodomorph Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had lo ...

dinosaurs (including ''

Riojasaurus ''Riojasaurus'' (meaning "lizard from La Rioja") was a herbivorous sauropodomorph dinosaur named after La Rioja Province in Argentina where it was found in the Los Colorados Formation in the Ischigualasto-Villa Unión Basin by José Bonaparte. ...

'', '' Coloradisaurus'' , and '' Lessemsaurus''), all of which shared the same

paleoenvironment Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...

with ''Zupaysaurus''. It is recognized as one of the earliest known faunal assemblages dominated by dinosaurs, which were 43% of the number of tetrapod species currently known. The non-dinosaurs that inhabited this locality included pseudosuchians,

therapsids Therapsida is a clade comprising a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including li ...

Cynodontia Cynodontia () is a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Mammals are cynodonts, as are their extinct ances ...

, other early reptiles, and possible

archosaurs Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics ...

References

External links

*
Zupaysaurus
' entry in The Theropod Database. {{Portal bar, Dinosaurs Theropoda Dinosaur genera Norian dinosaurs Los Colorados Formation Dinosaurs of Argentina Fossil taxa described in 2003 Taxa named by Rodolfo Coria