Tethyshadros
Encyclopedia
Tethyshadros is a genus
of hadrosauroid
dinosaur
from Italy
.
The genus was named and described by Italian paleontologist Fabio Marco Dalla Vecchia in 2009. Its only and type species
is Tethyshadros insularis. The genus name refers to the Tethys Ocean
and the Hadrosauroidea
. The specific name means "insular" or "of the island" in Latin
, a reference to the fact that the location of the find was at the time part of the Adriatic-Dinaric Island, one of the larger islands of the European Archipelago.
Tethyshadros is based on holotype
SC 57021, a mostly complete but crushed skeleton, that previously had been nicknamed "Antonio". The growth lines of the bones indicate that the specimen was perhaps five to six years old. It was found in the Villaggio del Pescatore site in the Province of Trieste
, near Duino Aurisina. This site was in the eighties discovered by Alceo Tarlao en Giorgio Rimoli in an old quarry near the sea. Here layers are exposed from the Liburnia Formation, from the Campanian
-Maastrichtian
, 71-70 million years old. In them a chalkstone lens
was present, containing fossils, ten metres thick and seventy metres in diameter. In 1994 student Tiziana Brazzatti in it discovered the hand bones of a larger skeleton. A company dealing in fossils, Stoneage, was given the commission to retrieve any remains, for which an overburden
of three hundred tons had to be removed. Later paleontologist Dalla Vecchia was brought in to provide professional guidance. In April 1999 "Antonio" was removed from the quarry, being slightly damaged by the process. Until December 2000 this specimen was during 2800 hours further prepared by spraying it with formic acid
to dissolve the chalk matrix and protecting the gradually exposed bone with resin. Another six specimina of Tethyshadros were discovered, one of them a skeleton that fell apart during the removal, another a skeleton of which only the forelimbs were recovered. All fossils are kept at the Museo Civico di Storia Naturale di Trieste but are property of the Italian State: "SC" stands for "State Collection".
With a length of about 4 metres (13.1 ft) and a weight of 350 kilograms (771.6 lb), Tethyshadros is a relatively small species, which has been explained by Dalla Vecchia as an instance of insular dwarfism
. The skull is relatively long, the neck and tail short, the legs, especially the shin bones, again long. These proportions, together with a reduction of the number of fingers, are seen as cursorial adaptations for bipedal running.
Tethyshadros shows a mix of basal and derived traits. A cladistic analysis indicated that it was closely related to the Hadrosauridae sensu Sereno and Telmatosaurus
. According to Dalla Vecchia, the presence of Tethyshadros on a European island is caused by a radiation of basal hadrosauroids, island-hopping from Asia. He rejects the possibility that the species is a relict of isolated evolution from earlier European hadrosauroids or descended from American hadrosaurs.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of hadrosauroid
Hadrosauroidea
Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and their close relatives. Many primitive hadrosauroids, such as the sail-backed Ouranosaurus, have traditionally been included in a paraphyletic "Iguanodontidae"...
dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
.
The genus was named and described by Italian paleontologist Fabio Marco Dalla Vecchia in 2009. Its only and type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Tethyshadros insularis. The genus name refers to the Tethys Ocean
Tethys Ocean
The Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.-Modern theory:...
and the Hadrosauroidea
Hadrosauroidea
Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and their close relatives. Many primitive hadrosauroids, such as the sail-backed Ouranosaurus, have traditionally been included in a paraphyletic "Iguanodontidae"...
. The specific name means "insular" or "of the island" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, a reference to the fact that the location of the find was at the time part of the Adriatic-Dinaric Island, one of the larger islands of the European Archipelago.
Tethyshadros is based on holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
SC 57021, a mostly complete but crushed skeleton, that previously had been nicknamed "Antonio". The growth lines of the bones indicate that the specimen was perhaps five to six years old. It was found in the Villaggio del Pescatore site in the Province of Trieste
Province of Trieste
The Province of Trieste is a province in the autonomous Friuli-Venezia Giulia region of Italy. Its capital is the city of Trieste.It has an area of 212 km², and a total population of 236,520...
, near Duino Aurisina. This site was in the eighties discovered by Alceo Tarlao en Giorgio Rimoli in an old quarry near the sea. Here layers are exposed from the Liburnia Formation, from the Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
-Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
, 71-70 million years old. In them a chalkstone lens
Lens (geology)
In geology a lens is a body of ore or rock or a deposit that is thick in the middle and thin at the edges, resembling a convex lens in cross-section. Adjective: "lenticular"....
was present, containing fossils, ten metres thick and seventy metres in diameter. In 1994 student Tiziana Brazzatti in it discovered the hand bones of a larger skeleton. A company dealing in fossils, Stoneage, was given the commission to retrieve any remains, for which an overburden
Overburden
Overburden is the material that lies above an area of economic or scientific interest in mining and archaeology; most commonly the rock, soil, and ecosystem that lies above a coal seam or ore body. It is also known as 'waste' or 'spoil'...
of three hundred tons had to be removed. Later paleontologist Dalla Vecchia was brought in to provide professional guidance. In April 1999 "Antonio" was removed from the quarry, being slightly damaged by the process. Until December 2000 this specimen was during 2800 hours further prepared by spraying it with formic acid
Formic acid
Formic acid is the simplest carboxylic acid. Its chemical formula is HCOOH or HCO2H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant, formica, referring to its early...
to dissolve the chalk matrix and protecting the gradually exposed bone with resin. Another six specimina of Tethyshadros were discovered, one of them a skeleton that fell apart during the removal, another a skeleton of which only the forelimbs were recovered. All fossils are kept at the Museo Civico di Storia Naturale di Trieste but are property of the Italian State: "SC" stands for "State Collection".
With a length of about 4 metres (13.1 ft) and a weight of 350 kilograms (771.6 lb), Tethyshadros is a relatively small species, which has been explained by Dalla Vecchia as an instance of insular dwarfism
Insular dwarfism
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of the reduction in size of large animals – typically mammals – when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf...
. The skull is relatively long, the neck and tail short, the legs, especially the shin bones, again long. These proportions, together with a reduction of the number of fingers, are seen as cursorial adaptations for bipedal running.
Tethyshadros shows a mix of basal and derived traits. A cladistic analysis indicated that it was closely related to the Hadrosauridae sensu Sereno and Telmatosaurus
Telmatosaurus
Telmatosaurus is a genus of basal hadrosaurid dinosaur from the Late Cretaceous. It was a relatively small hadrosaur, approximately five meters long, found in what is now Romania....
. According to Dalla Vecchia, the presence of Tethyshadros on a European island is caused by a radiation of basal hadrosauroids, island-hopping from Asia. He rejects the possibility that the species is a relict of isolated evolution from earlier European hadrosauroids or descended from American hadrosaurs.