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 n ...
of
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
Drepanosaurs (members of the clade Drepanosauromorpha) are a group of extinct reptiles that lived between the Carnian and Rhaetian stages of the late Triassic Period, approximately between 230 and 210 million years ago. The various species of dr ...
drepanosauromorph
Drepanosaurs (members of the clade Drepanosauromorpha) are a group of extinct reptiles that lived between the Carnian and Rhaetian stages of the late Triassic Period, approximately between 230 and 210 million years ago. The various species of dr ...
. 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 Museo may refer to:
* Museo, 2018 Mexican drama heist film
* Museo (Naples Metro), station on line 1 of the Naples Metro
* Museo, Seville, neighborhood of Seville, Spain
{{disambiguation ...
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 C ...
, 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, 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 ...
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
. 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 ...
, 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, 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 des ...
'' 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 referred to the
Zorzino Limestone Formation
The Calcare di Zorzino, Italian for Zorzino Limestone is a Late Triassic (Norian) geological formation in Italy (Cene and ).
Description
''Vallesaurus'' is a small drepanosaurid about long. The manus (hand) is
pentadactyl
Pentadactyl is a discontinued Firefox extension forked from the Vimperator and designed to provide a more efficient user interface for keyboard-fluent users. The design is heavily inspired by the Vim text editor, and the authors try to maintain ...
, 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 ''pla ...
.
''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 ...
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 characterist ...
. 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 ...
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'' w ...
'', another drepanosaur, in that it lacks the enormous claw found on the second digit of the
manus
Manus may refer to:
* Manus (anatomy), the zoological term for the distal portion of the forelimb of an animal (including the human hand)
* ''Manus'' marriage, a type of marriage during Roman times
Relating to locations around New Guinea
* Man ...
. It can be distinguished from ''Drepanosaurus'', ''Megalancosaurus'' and possibly ''
Dolabrosaurus
''Dolabrosaurus'' is a genus of extinct reptile and a member of the family Drepanosauridae. Fossils of ''Dolabrosaurus'' have been found in the Chinle Formation of New Mexico.Hypuronector'', a related drepanosaur, in having anteroposteriorly extended neural spines of the anterior dorsal vertebrae and forelimbs much shorter than the hindlimbs.