Elopteryx Temporal range: Maastrichtian | |
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The holotype femur fragment and referred tibiotarsus fragment in several views | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Clade: | Paraves |
Genus: | † Elopteryx Andrews, 1913 |
Type species | |
†Elopteryx nopcsai Andrews, 1913 | |
Synonyms | |
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Elopteryx is a genus of paravian theropod dinosaur based on fragmentary fossils found in Late Cretaceous rocks of Romania. The single species, Elopteryx nopcsai, was known only from very incomplete material until new specimens were reported in the 21st century. Balaur bondoc might represent a junior synonym of this taxon. [1] [2]
In the late nineteenth or early twentieth century, the famous Hungarian paleontologist Franz Nopcsa von Felső-Szilvás found near Sînpetru, in what is now the Romanian region of Transylvania, some bone fragments of a small theropod. These were acquired by the British Museum of Natural History. In 1913, curator Charles William Andrews named these as the type species Elopteryx nopcsai. The genus name Elopteryx is from Ancient Greek helos (ἕλος), "marsh" + pteryx (πτέρυξ), "wing". The specific name honors Nopcsa. Initially, Elopteryx was described from its holotype, a proximal left femur, specimen BMNH A1234. A second upper left thighbone fragment, BMNH A1235, was referred. A distal left tibiotarsus was also tentatively assigned to this taxon; it was initially classified with the same specimen number as the holotype and was found in close proximity, but may not be from the same individual (see below). This has since been relabeled and is now specimen BMNH A4359. The exact location and time of the discoveries are today unknown. The fossils date from the early-late Maastrichtian (Begudian) faunal stage, circa 70-66 million years ago, originating from the Sânpetru Formation of the Hațeg Island. The animal was by Andrews believed to be a pelecaniform seabird. [3] [4]
In 1929 the Hungarian paleontologist Kálmán Lambrecht referred two more specimens: BMNH A PAL.1528 and BMNH A PAL.1588, respectively a left and a right tibiotarsus. [5] In 1933 Lambrecht named a separate family Elopterygidae. [6] The supposed family Elopterygidae was initially placed in the suborder Sulae – then still in the polyphyletic "Pelecaniformes" – in 1963 by Pierce Brodkorb in his fossil bird catalogue, and the Cenozoic genera Argillornis and Eostega were moved to it. [7] These two are unequivocal derived neornith birds and the latter indeed seems to be an ancient sulid, whereas Argillornis has turned out to be referrable to the giant pseudotooth bird Dasornis which was almost certainly not very closely related to the Sulae. [8] Reconstruction attempts of E. nopcsai like this are based on this presumed affiliation with gannets and cormorants. But more recent studies would result in radically different interpretations.
In 1975, the distal tibiotarsi BMNH A1588 and BMNH A1528, together with BMNH A4359, were by Colin James Oliver Harrison and Cyril Alexander Walker removed from Elopteryx, redescribed as Bradycneme draculae and Heptasteornis andrewsi respectively, and used to establish a supposed family of gigantic two metre tall owls, the Bradycnemidae. [3] In 1978 Brodkorb had changed his opinion after the supposed Elopteryx material was divided among three species in total, and was actually the first scholar in modern times to suggest that these Mesozoic bones were not of birds but of non-avian dinosaurs. [9]
In 1981, Dan Grigorescu and Eugen Kessler stated that Elopteryx was a non-avian coelurosaurian dinosaur. They also referred a supposed distal femur (FGGUB R.351) to Elopteryx, [10] but both researchers (with Zoltan Csiki) later identified this specimen as a hadrosauroid distal metatarsal. [11]
In 1992, it was proposed by Jean Le Loeuff e.a. that Bradycneme and Heptasteornis should be synonymized with E. nopcsai again, and a femur (MDE-D203), an anterior dorsal vertebra (MDE-D01), a posterior sacral vertebra (MDE collection, unnumbered) and some dorsal rib fragments from the Jurassic Grès à Reptiles formation of France were described as an indeterminate species of Elopteryx; that study placed all this material in the Dromaeosauridae or a family or subfamily (Elopteryginae) very close to these. [12] The vertebrae were in 1998 separated again and assigned to a new dromaeosaurid, Variraptor mechinorum . [13] The French femur is similar in general appearance to the Elopteryx type but it differs in diagnostic traits, e.g. lacking a fourth trochanter. Also, neither the ribs nor the tibiotarsi can be compared to the type specimen of Elopteryx, there being no overlapping material.
In 2005, another (distal) femur piece, FGGUB R.1957, has been described as a new specimen of Elopteryx on the basis of the bone texture. [11] In 2019, a potential pelvis specimen identified as cf. E. nopcsai was reported. [14] In 2024, a new femur specimen from Romania was attributed to Elopteryx, and the specimen shows that it was secondarily flightless. [2]
Modern interpretations have differed on the question whether the Bradycneme and Heptasteornis material should be included — they have meanwhile been synonymized and split from each other and Elopteryx many times — and what the exact affiliations of the material would be. Various solutions were proposed for this problem. [15] Previously, some researchers proposed Elopteryx was a member of the Dromaeosauridae or Troodontidae, [16] without being able to support this with much empirical evidence. [11] In 1998 Csiki & Grigorescu suggested that Elopteryx belonged to the Maniraptora, while Bradycneme had a more basal position in the Tetanurae. [17]
Since the 21st century, Elopteryx has been supported widely as a member of the Maniraptora, with most studies recovering it as a member of the Paraves. In 2004, Darren Naish and Gareth Dyke considered Elopteryx as a Eumaniraptora incertae sedis , possibly either a non-ornithuromorphan pygostylian bird [18] or a troodontid, while Bradycneme would be a maniraptoran, and the dubious Heptasteornis (at least its holotype BMNH A4359) a member of the Alvarezsauridae. [19] Thus E. nopcsai seems to be some sort of birdlike eumaniraptoran, but not related to modern birds. In 2005, Kessler, Grigorescu and Csiki reunited all the material in Elopteryx but considered it an alvarezsaurid. [11] In a 2011 classification, Tom Holtz assigned Elopteryx to the Troodontidae. [20] In 2013, Stephen L. Brusatte and colleagues mentioned a possibility of Elopteryx and the paravian Balaur bondoc being the same taxon, though the authors did not consider it the most likely case. [1] Later, in 2019, two studies have found it to be an avialan once again, but a basal one; Hartman and colleagues recover it as a confuciusornithiform [21] while Mayr and colleagues note similarities with Gargantuavis and Balaur , suggesting they form a clade native to the Late Cretaceous European archipelago. [14] Mayr and colleagues also claimed that the synonymy of Elopteryx and Balaur remains possible and that more work is needed for confirmation. [14] In 2024, Stoicescu and colleagues suggested that Elopteryx is indeed a paravian and a member of the Avialae based on its new specimen, and that Balaur bondoc is probably a junior synonym of Elopteryx. [2]
Jinfengopteryx is a genus of maniraptoran dinosaur. It was found in the Qiaotou Member of the Huajiying Formation of Hebei Province, China, and is therefore of uncertain age. The Qiaotou Member may correlate with the more well-known Early Cretaceous Yixian Formation, and so probably dates to around 122 Ma ago.
Magyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period in Romania. It is one of the smallest-known adult sauropods, measuring only 6 m (20 ft) in length and 750–1,000 kg (1,650–2,200 lb) in body mass. The type and only certain species is Magyarosaurus dacus. It has been found to be a close relative of Rapetosaurus in the family Saltasauridae in the sauropod clade Titanosauria in a 2005 study.
Pyroraptor is an extinct genus of paravian dinosaur, probably a dromaeosaurid or unenlagiid, from the Late Cretaceous Ibero-Armorican island, of what is now southern France and northern Spain. It lived during the late Campanian and early Maastrichtian stages, approximately 70.6 million years ago. It is known from a single partial specimen that was found in Provence in 1992, after a forest fire. The animal was named Pyroraptor olympius by Allain and Taquet in 2000.
Betasuchus is a genus of theropod dinosaur which lived during the Late Cretaceous Period. Betasuchus is, besides Orthomerus, the only dinosaur genus named from remains found in the Netherlands and the only non-avian theropod found in the Maastrichtian Beds.
Bradycneme is a genus of theropod dinosaur from the Maastrichtian-age Upper Cretaceous Sânpetru Formation of the Hațeg Basin, Transylvania, Romania. The genus contains a single species, Bradycneme draculae, known only from a partial right lower leg, which its original describers believed came from a giant owl.
Variraptor is a dubious and potentially chimaeric genus of dromaeosaurid theropod dinosaur from the Late Cretaceous of France.
Heptasteornis is the name given to a dubious genus of alvarezsaurid dinosaur from the Late Cretaceous. The type species is Heptasteornis andrewsi, described as a presumed gigantic prehistoric owl in 1975. It was previously included in Elopteryx nopcsai and indeed the holotypes 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.
Ornithodesmus is a genus of small, dromaeosaurid dinosaur from the Isle of Wight in England, dating to about 125 million years ago. The name was originally assigned to a bird-like sacrum, initially believed to come from a bird and subsequently identified as a pterosaur. More complete pterosaur remains were later assigned to Ornithodesmus, until recently a detailed analysis determined that the original specimen in fact came from a small theropod, specifically a dromaeosaur, making it one of the first dromaeosaurs known to science. All pterosaurian material previously assigned to this genus has been renamed Istiodactylus.
Hațeg Island was a large offshore island in the Tethys Sea which existed during the Late Cretaceous period, probably from the Cenomanian to the Maastrichtian ages. It was situated in an area corresponding to the region around modern-day Hațeg, Hunedoara County, Romania. Maastrichtian fossils of small-sized dinosaurs have been found in the island's rocks. It was formed mainly by tectonic uplift during the early Alpine orogeny, caused by the collision of the African and Eurasian plates towards the end of the Cretaceous. There is no real present-day analog, but overall, the island of Hainan 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.
Hatzegopteryx is a genus of azhdarchid pterosaur found in the late Maastrichtian deposits of the Densuş Ciula Formation, an outcropping in Transylvania, Romania. It is known only from the type species, Hatzegopteryx thambema, named by Buffetaut et al. in 2002 based on parts of the skull and humerus. Additional specimens, including a neck vertebra, were later placed in the genus, representing a range of sizes. The largest of these remains indicate it was among the biggest pterosaurs, with an estimated wingspan of 10 to 12 metres.
Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the avialans, which include diverse extinct taxa as well as the over 10,000 species of living birds. Basal members of Paraves are well known for the possession of an enlarged claw on the second digit of the foot, which was held off the ground when walking in some species. A number of differing scientific interpretations of the relationships between paravian taxa exist. New fossil discoveries and analyses make the classification of Paraves an active subject of research.
Gargantuavis is an extinct genus of large, primitive bird containing the single species Gargantuavis philoinos. It is the only member of the monotypic family Gargantuaviidae. Its fossils were discovered in several formations dating to 73.5 and 71.5 million years ago in what is now northern Spain, southern France, and Romania. Gargantuavis is the largest known bird of the Mesozoic, a size ranging between the cassowary and the ostrich, and a mass of 141 kg (311 lb) like modern ostriches, exemplifying the extinction of non-avian dinosaurs was not a necessary condition for the emergence of giant terrestrial birds. It was once thought to be closely related to modern birds, but the 2019 discovery of a pelvis identified as cf. Elopteryx nopcsai from what was Hateg Island shows several primitive features.
The Densuș-Ciula Formation is a geological formation in Romania whose strata date back to the Late Cretaceous. It forms part of the Hațeg Island assemblage. Dinosaur remains are among the fossils that have been recovered from the formation. It is divided up into three members, the lower member is noted for high content of volcanogenic material and is poorly fossiliferous. While the Middle member consists of silty mudstones, sandstones and conglomerates containing volcanogenic clasts and is richly fossiliferous, while the upper member consists of matrix supported red conglomerates and is poorly fossiliferous.
Hesperonychus is a genus of small paravian theropod dinosaur. It may be a dromaeosaurid or an avialan. There is one described species, Hesperonychus elizabethae. The type species was named in honor of Dr. Elizabeth Nicholls of the Royal Tyrrell Museum of Palaeontology who collected it as a student in 1982. It is known from fossils recovered from the lowermost strata of the Dinosaur Park Formation and possibly the Oldman Formation of Alberta, dating to the Campanian stage of the Late Cretaceous around 75 million years ago.
The Sânpetru Formation is an early Maastrichtian geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation. It is located in Romania, near Sânpetru village, part of Sântămăria-Orlea commune. It forms a component of the Hațeg Island fauna.
Paludititan is a genus of titanosaurian sauropod dinosaur which lived in the area of present Romania during the Late Cretaceous. It existed in the island ecosystem known as Hațeg Island.
Balaur is a genus of theropod dinosaur from the late Cretaceous period, in what is now Romania. It is the type species of the monotypic genus Balaur, after the balaur, a dragon of Romanian folklore. The specific name bondoc means "stocky", so Balaur bondoc means "stocky dragon" in Romanian. This name refers to the greater musculature that Balaur had compared to its relatives. The genus, which was first described by scientists in August 2010, is known from two partial skeletons. Some researchers suggest that the taxon might represent a junior synonym of Elopteryx.
Anchiornithidae is a family of small paravian dinosaurs. Anchiornithids have been classified at varying positions in the paravian tree, with some scientists classifying them as a distinct family, a basal subfamily of Troodontidae, members of Archaeopterygidae, or an assemblage of dinosaurs that are an evolutionary grade within Avialae or Paraves.
Imperobator is a genus of paravian theropod, a group of large, three-toed carnivorous dinosaurs, that lived during the Maastrichtian age of the Late Cretaceous period in what is now James Ross Island in Antarctica. Imperobator is one of only two non-avian theropods known from Antarctica, crossing over to the landmass when it was part of Gondwana. The only described specimen was found in 2003 by an expedition launched by the University of California Museum of Paleontology and initially described as a dromaeosaur in 2007. However, later searches reported more fossils from the site including teeth and skull bones. The fossils were formally described as a new genus of giant paravian in 2019.
The Sebeș Formation is a geological formation in Romania. It is of Maastrichtian age. It is laterally equivalent to the Sard Formation. The base of the formation consists of claystones interbedded with sandstones and conglomerates. It is well known for its fossils which form a component of the Hațeg Island fauna.