Heptasteornis
Encyclopedia
Heptasteornis is the name given to a dubious genus
of small dinosaur
from the Late Cretaceous
. The type (and only known) species is Heptasteornis andrewsi, described as a presumed gigantic prehistoric owl
in 1975. It was previously included in Elopteryx nopcsai and indeed the holotype
s of both were believed to be from the same individual as they were discovered, and initially were assigned the same specimen number. This appears to be in error however (see below).
The material was discovered in Romania
, in the late Maastrichtian
Sânpetru Formation
(Rognacian faunal stage
, deposited c. 68-65.5 million years ago) of the Haţeg Basin
in Transylvania
. The scientific name means "C.W. Andrews' Transylvanian bird", after the discoverer of the first specimen and Ancient Greek
(h)epta (επτά) "seven" + asty (άστυ) "city" + ornis (όρνις) "bird"; the Latin
septum urbium or the German Siebenbürgen - meaning "seven cities" or "seven castles" - were common names for the Transylvanian region throughout the centuries.
The material was originally limited to a mere two broken distal tibiotarsi, BMNH
A4359 (the holotype) and A1528. The taxonomic status and systematic
placement of these bones was much disputed and they were often considered junior synonyms of Bradycneme
or Elopteryx. Given the fragmentary nature of the fossils, little could be resolved and Heptasteornis was (and still is) considered a nomen dubium
by many.
However, more recently the bones were reassessed as an alvarezsaurid, the first to be known from Europe, and this theory, originally proposed in 1988, has since withstood further scrutiny. Bradycneme and Elopteryx on the other hand seem to be more advanced maniraptora
n theropods. The results of the restudy of BMNH A4359 also suggest that a distal piece of femur
, specimen FGGUB R.1957, probably can also be assigned to Heptasteornis.
Thus, quite ironically, of those three enigmatic Romanian theropods the one most explicitly named a "bird" - as per its scientific name - is almost certainly the one most distantly related to birds.
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 small 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 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...
. The type (and only known) species is Heptasteornis andrewsi, described as a presumed gigantic prehistoric owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
in 1975. It was previously included in Elopteryx nopcsai and indeed 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...
s of both were believed to be from the same individual as they were discovered, and initially were assigned the same specimen number. This appears to be in error however (see below).
The material was discovered in 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...
, in 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...
Sânpetru Formation
Sânpetru Formation
The Sânpetru Formation is a Mesozoic geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation. It is located near Sânpetru village, part of Sântămăria-Orlea commune.-Ornithischians:-Sauropods:-Theropods:...
(Rognacian faunal stage
Faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...
, deposited c. 68-65.5 million years ago) of the Haţeg Basin
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...
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 scientific name means "C.W. Andrews' Transylvanian bird", after the discoverer of the first specimen and Ancient 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...
(h)epta (επτά) "seven" + asty (άστυ) "city" + ornis (όρνις) "bird"; the 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...
septum urbium or the German Siebenbürgen - meaning "seven cities" or "seven castles" - were common names for the Transylvanian region throughout the centuries.
The material was originally limited to a mere two broken distal tibiotarsi, BMNH
BMNH
BMNH may refer to:*British Museum of Natural History, commonly known as Natural History Museum, in London, the United Kingdom*Beijing Museum of Natural History, in Beijing, China...
A4359 (the holotype) and A1528. The taxonomic status and systematic
Systematic
Systematic is an American hard rock band from Oakland, California. They were one of the first signings to Metallica drummer Lars Ulrich's record label, The Music Company, via Elektra Records. The band released two studio albums before disbanding in 2004....
placement of these bones was much disputed and they were often considered junior synonyms of Bradycneme
Bradycneme
Bradycneme is a genus of theropod dinosaur from the early Maastrichtian-age Upper Cretaceous Sânpetru Formation of the Haţeg Basin, Transylvania, Romania. It is known only from a partial right lower leg , which its describers believed came from a giant owl.-History:Harrison and Walker described...
or Elopteryx. Given the fragmentary nature of the fossils, little could be resolved and Heptasteornis was (and still is) considered a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
by many.
However, more recently the bones were reassessed as an alvarezsaurid, the first to be known from Europe, and this theory, originally proposed in 1988, has since withstood further scrutiny. Bradycneme and Elopteryx on the other hand seem to be more advanced maniraptora
Maniraptora
Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the dinosaurs that were more closely related to them than to Ornithomimus velox. It contains the major subgroups Avialae, Deinonychosauria, Oviraptorosauria and Therizinosauria. Ornitholestes and the Alvarezsauroidea...
n theropods. The results of the restudy of BMNH A4359 also suggest that a distal piece of 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...
, specimen FGGUB R.1957, probably can also be assigned to Heptasteornis.
Thus, quite ironically, of those three enigmatic Romanian theropods the one most explicitly named a "bird" - as per its scientific name - is almost certainly the one most distantly related to birds.