Hateg Island
Encyclopedia
Hațeg Island was a large offshore island
in the Tethys Sea during the Cretaceous
period. It was situated in an area corresponding to the region around modern-day Hațeg
, Romania
. Maastrichtian
fossil
s of small-sized dinosaur
s have been found in the erstwhile island's rocks.
It was formed mainly by tectonic uplift
during the early Alpine orogeny
, caused by the Adriatic Plate's northwest movement across the Piemont-Liguria Ocean
towards the end of the Cretaceous. There is no real present-day analog, but overall, the island of Hainan
(off the coast of China
) is perhaps closest as regards climate
, geology
and topography
, though still not a particularly good match. The vegetation
, for example, was of course entirely distinct from today, as was the fauna
.
The Hungarian paleontologist Franz Nopcsa theorized that "limited resources" found on the island commonly have an effect of "reducing the size of animals" over the generations, producing a localized form of dwarfism. Nopcsa's theory of insular dwarfism
— also known as the island rule — is today widely accepted.
. Among them are included:
Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...
in the Tethys Sea during the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period. It was situated in an area corresponding to the region around modern-day Hațeg
Hateg
Hațeg is a town in Hunedoara County, Romania with a population of 12,507. Three villages are administered by the town: Nălațvad, Silvașu de Jos and Silvașu de Sus.Țara Hațegului is the region around Hațeg town...
, Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
. 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...
fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of small-sized 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...
s have been found in the erstwhile island's rocks.
It was formed mainly by tectonic uplift
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...
during the early Alpine orogeny
Alpine orogeny
The Alpine orogeny is an orogenic phase in the Late Mesozoic and Tertiary that formed the mountain ranges of the Alpide belt...
, caused by the Adriatic Plate's northwest movement across the Piemont-Liguria Ocean
Piemont-Liguria Ocean
The Piemont-Liguria basin or the Piemont-Liguria Ocean was a former piece of oceanic crust that is seen as part of the Tethys Ocean...
towards the end of the Cretaceous. There is no real present-day analog, but overall, the island of Hainan
Hainan
Hainan is the smallest province of the People's Republic of China . Although the province comprises some two hundred islands scattered among three archipelagos off the southern coast, of its land mass is Hainan Island , from which the province takes its name...
(off the coast of China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
) is perhaps closest as regards climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
, geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
and topography
Topography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
, though still not a particularly good match. The vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
, for example, was of course entirely distinct from today, as was the fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...
.
The Hungarian paleontologist Franz Nopcsa theorized that "limited resources" found on the island commonly have an effect of "reducing the size of animals" over the generations, producing a localized form of dwarfism. Nopcsa's theory 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...
— also known as the island rule — is today widely accepted.
Paleofauna
About nine species of dinosaurs, and one species of pterosaur are thought to have been indigenous to the island. Most of these animals were smaller versions of mainland megafauna, which became smaller due to island dwarfism, although this is certainly not the case for Hatzegopteryx which, being one of the biggest pterosaurs ever, is an example of island gigantismIsland gigantism
Island gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives....
. Among them are included:
- Theriosuchus sympiestodonTheriosuchusTheriosuchus is an extinct genus of atoposaurid mesoeucrocodylian from the Late Jurassic of Europe, the Early Cretaceous of Asia and the Late Cretaceous of Romania. The five species are T. pusillus from England , T. ibericus from Spain , T. guimarotae from Portugal , T. sympiestodon from Romania...
, an atoposauridAtoposauridaeAtoposauridae is a family of crocodile-like archosaurs. Members of the family have been found from France, Spain, Portugal, Romania, Germany, Kazakhstan, the United Kingdom, the United States, Cameroon, and Thailand.-Phylogeny:... - Hatzegopteryx thambemaHatzegopteryxHatzegopteryx is a genus of azhdarchid pterosaur, known from incomplete remains found in Transylvania. The skull fragments, left humerus, and other fossilized remains indicate it was among the largest pterosaurs. The skeleton of Hatzegopteryx has been considered identical to the known remains of...
, a pterosaurPterosaurPterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight... - Rhabdodon priscusRhabdodonRhabdodon is a genus of dinosaur that lived in Europe approximately 70 million years ago in the Late Cretaceous. It is unclear whether it was an iguanodont or a hypsilophodont, and may be a "missing link" between the two. Current evidence indicates it is an iguanodont similar to Tenontosaurus...
, an ornithopodOrnithopodOrnithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American... - Telmatosaurus transylvanicusTelmatosaurusTelmatosaurus 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....
, a hadrosaur - Struthiosaurus transylvanicusStruthiosaurusStruthiosaurus is one of the smallest known and most basal genera of nodosaurid dinosaurs, from the Late Cretaceous period of Austria, Romania and France in Europe. It was protected by body armour...
, a nodosaur - Magyarosaurus dacusMagyarosaurusMagyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period in what is now Romania. It is one of the smallest-known adult sauropods, measuring only six meters in length. The type species is Magyarosaurus dacus...
, a titanosaurTitanosaurTitanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus. It includes some of the heaviest creatures ever to walk the earth, such as Argentinosaurus and Paralititan — which some believe have weighed up to 100 tonnes... - Paludititan nalatzensisPaludititanPaludititan is a genus of titanosaurian dinosaur which existed in what is now Haţeg Basin, Romania during the late Cretaceous period. The type species is Paludititan nalatzensis, after its finding place Nǎlaţ-Vad. The type species was determined and described by Zoltán Csiki, Vlad Codrea, Cǎtǎlin...
, a titanosaur - Elopteryx nopcsaiElopteryxElopteryx is a genus of troodontid maniraptoran theropod dinosaur based on fragmentary fossils found in late Cretaceous Period rocks of Romania. These fossils date from the early-mid Maastrichtian faunal stage, c.71-68 million years ago...
, a theropod - Megalosaurus hungaricus, a theropod
- Balaur bondoc, a theropod