''Vallesaurus'' is an

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 extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 ...

elyurosaur drepanosauromorph. First found in

Northern Italy Northern Italy ( it, Italia settentrionale, it, Nord Italia, label=none, it, Alta Italia, label=none or just it, Nord, label=none) is a geographical and cultural region in the northern part of Italy. It consists of eight administrative regions ...

in 1975, it is one of the most primitive drepanosaurs. ''V. cenenis'' is 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 ...

, which was first mentioned in 1991 but only formally described in 2006. A second species, ''V. zorzinensis'', was named in 2010.

Discovery

The first specimen of ''Vallesaurus cenensis'', MCSNB 4751, was found in 1975 by the staff of the Museo Civico di Scienze Naturali of

Bergamo Bergamo (; lmo, Bèrghem ; from the proto- Germanic elements *''berg +*heim'', the "mountain home") is a city in the alpine Lombardy region of northern Italy, approximately northeast of Milan, and about from Switzerland, the alpine lakes Como ...

, Italy. The genus was named in respect of professor Valle, the former director of the museum. The species, on the other hand, was named after a local municipality called

Cene Cene may refer to: People * Cene Marković, Serbian commander * Cene Prevc (born 1996), Slovenian ski jumper * Charles Le Cène (1647?–1703), French controversialist * Ilhami Çene (born 1909), Turkish fencer * Michel-Charles Le Cène (1684–17 ...

, which was neighboring the site where the fossil was excavated. The specimen was given to

palaeontologist 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 ...

Rupert Wild Rupert may refer to: People * Rupert (name), various people known by the given name or surname "Rupert" Places Canada *Rupert, Quebec, a village *Rupert Bay, a large bay located on the south-east shore of James Bay *Rupert River, Quebec *Rupert' ...

to study at the Staatliches Museum of

Stuttgart Stuttgart (; Swabian: ; ) is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley known as the ''Stuttgarter Kessel'' (Stuttgart Cauldron) and lies an hour from the ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. Wild briefly mentioned "Vallesaurus cenensis" in

1991 File:1991 Events Collage.png, From left, clockwise: Boris Yeltsin, elected as Russia's first president, waves the new flag of Russia after the 1991 Soviet coup d'état attempt, orchestrated by Soviet hardliners; Mount Pinatubo erupts in the Phil ...

, but without describing it formally or identifying the holotype specimen. Pinna (1993) listed the name when surveying Triassic reptiles in Italy, and identified MCSNB 4751 as its holotype. Renesto and Binelli formally described ''Vallesaurus cenensis'' in

2006 File:2006 Events Collage V1.png, From top left, clockwise: The 2006 Winter Olympics open in Turin; Twitter is founded and launched by Jack Dorsey; The Nintendo Wii is released; Montenegro 2006 Montenegrin independence referendum, votes to declare ...

, and attributed the name to Wild. However, Renesto ''et al.'' (2010) later attributed the name to Renesto & Binelli (2006), arguing that ''Vallesaurus cenensis'' was a ''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

'' prior to that study. A second species, ''V. zorzinensis'', was found in the same location and identified from the specimen MCSNB 4783. Its

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 ...

referred to the Zorzino Limestone Formation, where the holotype was found.

Description

''Vallesaurus'' is a small drepanosaurid about long. The manus (hand) is pentadactyl, with the 4th digit being the longest and equal in length to the

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

. The tarsus (ankle) has a centrale which articulates with the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

. In addition, the foot of ''Vallesaurus'' also has modified distal tarsals and

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 med ...

s, and a clawless

hallux Toes are the digits (fingers) of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being '' digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being '' pl ...

. ''Vallesaurus'' differs in some characteristics from another drepanosaur, ''

Megalancosaurus ''Megalancosaurus'' is a genus of extinct reptile from the Late Triassic Dolomia di Forni Formation and Zorzino Limestone of northern Italy, and one of the best known drepanosaurids. The type species is ''M. preonensis''; a translation of the a ...

''. ''Vallesaurus'' has a proportionally shorter and higher snout, a thicker and larger

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. The t ...

and set of maxillary teeth, and a shorter cervical

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

. It also lacks the fusion between the

neural spine The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

s of the second and third dorsal vertebrae. ''Vallesaurus'' differs from ''

Drepanosaurus ''Drepanosaurus'' (; "sickle lizard") is a genus of arboreal (tree-dwelling) reptile that lived during the Triassic Period. It is a member of the Drepanosauridae, a group of diapsid reptiles known for their prehensile tails. ''Drepanosaurus'' wa ...

'', another drepanosaur, in that it lacks the enormous claw found on the second digit of the manus. It can be distinguished from ''Drepanosaurus'', ''Megalancosaurus'' and possibly '' Dolabrosaurus'' in the lack of a terminal spine at the end of the tail. In addition, ''Vallesaurus'' also differs from ''

Hypuronector ''Hypuronector'' is a genus of extinct drepanosaur reptile from the Triassic Period that lived in what is now New Jersey. The etymology of the name translates as "deep-tailed swimmer from the lake," in reference to its assumed aquatic habits hypo ...

'', a related drepanosaur, in having anteroposteriorly extended neural spines of the anterior dorsal vertebrae and forelimbs much shorter than the hindlimbs.

References

{{Taxonbar, from=Q4008216 Fossils of Italy Drepanosaurs Fossil taxa described in 2006 Prehistoric reptile genera