Hatzegopteryx
Encyclopedia
Hatzegopteryx is a genus
of azhdarchid
pterosaur
, known from incomplete remains found in Transylvania
. The skull fragments, left humerus, and other fossil
ized remains indicate it was among the largest pterosaurs. The skeleton of Hatzegopteryx has been considered identical to the known remains of Quetzalcoatlus northropi. Q. northropi has not yet been properly described, and if it is not a nomen dubium
, Hatzegopteryx is possibly its junior synonym.
name is derived from the Hatzeg (or Hațeg
) basin of Transylvania, the so-called Hațeg Island
, where the bones were found, and from Greek
pteryx, or 'wing'. The specific name thambema is derived from the Greek for 'monster', in reference to its huge size.
Hatzegopteryx hails from the Densuș-Ciula Formation of western Romania
, which has been dated to the late Maastrichtian
stage of the late Cretaceous
Period, around 65 million years ago. The holotype
, FGGUB R 1083A, consists of the back part of the skull and the damaged proximal part of a left humerus. A 38.5 centimeter long middle section of a femur
found nearby, FGGUB R1625, may also have belonged to Hatzegopteryx.
, though in Hatzegopteryx the skull was much more heavily built, and had a markedly different jaw articulation, similar to that seen in Pteranodon
. Based on comparisons with other pterosaurs, Nyctosaurus
and Anhanguera
, Buffetaut and colleagues when initially describing the specimens estimated that the skull of Hatzegopteryx was probably almost three meters (ten feet) in length, which would have made it larger than that of the largest Quetzalcoatlus species and among the largest skulls of any known non-marine
animals.
The skull of Hatzegopteryx was also unique in its heavy, robust construction. Most pterosaur skulls are made up of very lightweight plates and struts. In Hatzegopteryx, the skull bones are stout and robust, with large-ridged muscle insertion areas. In their 2002 description, Buffetaut and colleagues suggested that in order to fly, the skull weight of this pterosaur must have been reduced in some unconventional way (while they allowed that it could have been flightless, they found this unlikely due to the similarity of its wing bones to flying pterosaurs). The authors theorized that the necessary weight reduction was accomplished by the internal structure of the skull bones, which were full of small pits and hollows (alveoli) up to 10 mm long, separated by a matrix of incredibly thin bony struts (trabeculae), a feature also found in some parts of Hatzegopteryx wing bones. The authors pointed out that this unusual construction, which differed significantly from the irregular internal structure of other pterosaur skulls, resembles the structure of expanded polystyrene, the substance used to make Styrofoam
. They noted that this would allow a sturdy, stress-resistant construction while remaining lightweight, and would have allowed the huge-headed animal to fly.
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 azhdarchid
Azhdarchidae
Azhdarchidae is a family of pterosaurs known primarily from the late Cretaceous Period, though an isolated vertebrae apparently from an azhdarchid is known from the early Cretaceous as well...
pterosaur
Pterosaur
Pterosaurs 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...
, known from incomplete remains found in Transylvania
Transylvania
Transylvania is a historical region in the central part of Romania. Bounded on the east and south by the Carpathian mountain range, historical Transylvania extended in the west to the Apuseni Mountains; however, the term sometimes encompasses not only Transylvania proper, but also the historical...
. The skull fragments, left humerus, and other fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
ized remains indicate it was among the largest pterosaurs. The skeleton of Hatzegopteryx has been considered identical to the known remains of Quetzalcoatlus northropi. Q. northropi has not yet been properly described, and if it is not a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
, Hatzegopteryx is possibly its junior synonym.
Naming and fossils
The genus was named in 2002 by French paleontologist Eric Buffetaut, and Romanian paleontologists Dan Grigorescu and Zoltan Csiki. It is known from only the type species, Hatzegopteryx thambema. The genericGenus
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...
name is derived from the Hatzeg (or 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...
) basin of Transylvania, the so-called Hațeg Island
Hateg Island
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...
, where the bones were found, and from Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
pteryx, or 'wing'. The specific name thambema is derived from the Greek for 'monster', in reference to its huge size.
Hatzegopteryx hails from the Densuș-Ciula Formation of western 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...
, which has been dated to the late 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...
stage of the late 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, around 65 million years ago. The 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...
, FGGUB R 1083A, consists of the back part of the skull and the damaged proximal part of a left humerus. A 38.5 centimeter long middle section of a femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
found nearby, FGGUB R1625, may also have belonged to Hatzegopteryx.
Skull
Hatzegopteryx apparently had a robust skull broadened in the rear, and a massive jaw. Its lower jaw featured a unique groove in its point of articulation, also seen in some other pterosaurs, that would have allowed the animal to achieve a very wide gape. Many of the fossilized bones of Hatzegopteryx resemble those of the closely related Quetzalcoatlus sp.Quetzalcoatlus
Quetzalcoatlus was a pterodactyloid pterosaur known from the Late Cretaceous of North America , and one of the largest known flying animals of all time. It was a member of the Azhdarchidae, a family of advanced toothless pterosaurs with unusually long, stiffened necks...
, though in Hatzegopteryx the skull was much more heavily built, and had a markedly different jaw articulation, similar to that seen in Pteranodon
Pteranodon
Pteranodon , from the Late Cretaceous geological period of North America in present day Kansas, Alabama, Nebraska, Wyoming, and South Dakota, was one of the largest pterosaur genera and had a maximum wingspan of over...
. Based on comparisons with other pterosaurs, Nyctosaurus
Nyctosaurus
Nyctosaurus is a genus of pterodactyloid pterosaur, the remains of which have been found in the Niobrara Formation of the mid-western United States, which, during the late Cretaceous Period, was covered in an extensive shallow sea. The genus Nyctosaurus has had numerous species referred to it,...
and Anhanguera
Anhanguera (pterosaur)
Anhanguera is a genus of pterodactyloid pterosaur known from the Lower-Cretaceous Santana Formation of Brazil, with referred specimens found in the Upper Chalk Formation and Cambridge Greensand of the UK...
, Buffetaut and colleagues when initially describing the specimens estimated that the skull of Hatzegopteryx was probably almost three meters (ten feet) in length, which would have made it larger than that of the largest Quetzalcoatlus species and among the largest skulls of any known non-marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
animals.
The skull of Hatzegopteryx was also unique in its heavy, robust construction. Most pterosaur skulls are made up of very lightweight plates and struts. In Hatzegopteryx, the skull bones are stout and robust, with large-ridged muscle insertion areas. In their 2002 description, Buffetaut and colleagues suggested that in order to fly, the skull weight of this pterosaur must have been reduced in some unconventional way (while they allowed that it could have been flightless, they found this unlikely due to the similarity of its wing bones to flying pterosaurs). The authors theorized that the necessary weight reduction was accomplished by the internal structure of the skull bones, which were full of small pits and hollows (alveoli) up to 10 mm long, separated by a matrix of incredibly thin bony struts (trabeculae), a feature also found in some parts of Hatzegopteryx wing bones. The authors pointed out that this unusual construction, which differed significantly from the irregular internal structure of other pterosaur skulls, resembles the structure of expanded polystyrene, the substance used to make Styrofoam
Styrofoam
Styrofoam is a trademark of The Dow Chemical Company for closed-cell currently made for thermal insulation and craft applications. In 1941, researchers in Dow's Chemical Physics Lab found a way to make foamed polystyrene...
. They noted that this would allow a sturdy, stress-resistant construction while remaining lightweight, and would have allowed the huge-headed animal to fly.