extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
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 nomencla ...
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 lon ...
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 ...
known from the
Late Triassic
The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. Th ...
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age ( Late Triassic), and is notable for its fossils of cynodonts, "rauisuchian" pseudosuchians, and early dinosaurs and o ...
of
Rio Grande do Sul
Rio Grande do Sul (, , ; "Great River of the South") is a state in the southern region of Brazil. It is the fifth-most-populous state and the ninth largest by area. Located in the southernmost part of the country, Rio Grande do Sul is border ...
,
southern Brazil
The South Region of Brazil (; ) is one of the five regions of Brazil. It includes the states of Paraná, Rio Grande do Sul, and Santa Catarina, and covers , being the smallest region of the country, occupying only about 6.76% of the territory o ...
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Mozam ...
.
Discovery and naming
''Saturnalia'' was originally named on the basis of three partial skeletons. 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 several ...
articulated
An articulated vehicle is a vehicle which has a permanent or semi-permanent pivot joint in its construction, allowing it to turn more sharply. There are many kinds, from heavy equipment to buses, trams and trains. Steam locomotives were somet ...
postcrania Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...
l
skeleton
A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...
Rio Grande do Sul
Rio Grande do Sul (, , ; "Great River of the South") is a state in the southern region of Brazil. It is the fifth-most-populous state and the ninth largest by area. Located in the southernmost part of the country, Rio Grande do Sul is border ...
geopark
A geopark is a protected area with internationally significant geology within which sustainable development is sought and which includes tourism, conservation, education and research concerning not just geology but other relevant sciences.
In 200 ...
of Paleorrota. The two paratypes are MCP 3845-PV, partial skeleton including natural cast of partial
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
with
teeth
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, tea ...
and some postcranial remains, and MCP 3846-PV, partial skeleton including postcranial remains. All specimens were collected in the "Wald-Sanga" (also known as "Sanga do Mato") locality from the Alemoa Member of the
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age ( Late Triassic), and is notable for its fossils of cynodonts, "rauisuchian" pseudosuchians, and early dinosaurs and o ...
(Rosário do Sul Group), dating to the
Carnian
The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic Series (or earliest age of the Late Triassic Epoch). It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by ...
faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convent ...
of the early
Late Triassic
The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. Th ...
, about 228
million years ago
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds.
Usage
Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...
. A partial
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 ...
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Mozam ...
has been speculated to belong to the genus. It is one of the oldest true dinosaurs yet found. It probably grew to about 1.5 meters (5 ft) long and . A U→Pb (
Uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly ...
decay) dating found that the Santa Maria Formation dated around 233.23 million years ago, putting it 1.5 million years older than the
Ischigualasto Formation
The Ischigualasto Formation is a Late Triassic fossiliferous formation and Lagerstätte in the Ischigualasto-Villa Unión Basin of the southwestern La Rioja Province and northeastern San Juan Province in northwestern Argentina. The formation ...
, and making the two formations approximately equal as the earliest dinosaur localities.
''Saturnalia'' was first named by Max C. Langer, Fernando Abdala, Martha Richter, Michael J. Benton in
1999
File:1999 Events Collage.png, From left, clockwise: The funeral procession of King Hussein of Jordan in Amman; the 1999 İzmit earthquake kills over 17,000 people in Turkey; the Columbine High School massacre, one of the first major school shoot ...
and 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 specimen( ...
is ''Saturnalia tupiniquim''. The generic name is derived from ''Saturnalia'',
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
for "Carnival", in reference to the discovery of the paratypes during the feasting period. The specific name is derived from
Portuguese
Portuguese may refer to:
* anything of, from, or related to the country and nation of Portugal
** Portuguese cuisine, traditional foods
** Portuguese language, a Romance language
*** Portuguese dialects, variants of the Portuguese language
** Portu ...
The primitive nature of ''Saturnalia'', combined with its mixture of sauropodomorph and
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 ca ...
characteristics, has made it difficult to classify.
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 foss ...
Max Cardoso Langer and colleagues, in their 1999 description of the genus, assigned it to the Sauropodomorpha.Langer, M.C., Abdala, F., Richter, M., and Benton, M. (1999). A sauropodomorph dinosaur from the Upper Triassic (Carnian) of southern Brazil. ''Comptes Rendus de l'Académie des Sciences'', 329: 511-;517. However, in a 2003 paper, Langer noted that features of its skull and hand were more similar to the
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 ca ...
José Bonaparte
José Fernando Bonaparte (14 June 1928 – 18 February 2020) was an Argentine paleontologist who discovered a plethora of South American dinosaurs and mentored a new generation of Argentine paleontologists
. One of the best-known Argentine paleo ...
and colleagues, in a 2007 study, found ''Saturnalia'' to be very similar to the primitive saurischian ''
Guaibasaurus
''Guaibasaurus'' is an extinct genus of basal saurischian dinosaur known from the Late Triassic Caturrita Formation of Rio Grande do Sul, southern Brazil. Most analyses recover it as a sauropodomorph, although there are some suggestions that ...
''. Bonaparte placed the two in the same
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...
,
Guaibasauridae
Guaibasauridae is a family of basal sauropodomorph dinosaurs, known from fossil remains of late Triassic period formations in Brazil and Argentina.
Classification
The exact makeup and classification of the Guaibasauridae remain uncertain. The ...
. Like Langer, Bonaparte found that these forms may have been primitive sauropodomorphs, or an assemblage of forms close to the common ancestor of the sauropodomorphs and theropods. Overall, Bonaparte found that both ''Saturnalia'' and ''Guaibasaurus'' were more theropod-like than prosauropod-like. However, all more recent
cladistic
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived cha ...
analyses found it to be a very basal sauropodomorph, possibly guaibasaurid, as the family was found to nest in a basal position within Sauropodomorpha.
tupiniquim
Tupiniquim (also Tupinã-ki, Topinaquis, Tupinaquis, Tupinanquins, Tupiniquins) are an indigenous people of Brazil, who now live in three indigenous territories (''Terras Indígenas'' in Portuguese). The indigenous territories (Caieiras Velhas ...