Despite the meaning of the group's name, not all pteranodontoids were toothless, the earlier genera such as the istiodactylids and anhanguerids had teeth that they used to catch prey, and several conclusions had led to the idea that they later evolved into the toothless pteranodontids. Pteranodontoids were also the most diverse group of pterosaurs throughout the Cretaceous period, and therefore the most successful flyers during their time.[4] They were mostly replaced by the larger azhdarchids at the end of the Late Cretaceous however, which resulted in resource and terrain competitions, but even so, pteranodontoids still managed to thrive with them, and genera such as Alcione, Barbaridactylus, and Simurghia lived until the Cretaceous-Paleogene extinction event. Pteranodontoids had similar a similar diet to modern-day soaring birds such the albatross, which mainly consisted of fish. Some genera of this group however, fed mainly on carrion, this can be seen on the earlier genera such as Istiodactylus. They were also known for their proportionally large wingspans, the largest recorded of any pteranodontoid reached 8.70 meters (28.5ft), and it belongs to the genus Tropeognathus.[5]
History of early discovered genera
Lectotype rostrum of Lonchodraco giganteus, the first ever known pteranodontoid
Several fossil remains were found in the Chalk Formation of England, a chalk pit known for its wide variety of fossils belonging to different animals. BritishpaleontologistJames Scott Bowerbank named and described the specimens found as a new species of Pterodactylus, P. giganteus due to its much larger size.[6]P. giganteus is nowadays considered to belong to the genus called Lonchodraco.[7] In 1851, Bowerbank unearthed more specimens in the same chalk pit as P. giganteus, and assigned these specimens to yet another newly named species of Pterodactylus, known as P. cuvieri, in honor of the German naturalist and zoologistGeorges Cuvier.[8] Later that year, British paleontologist Sir Richard Owen had also unearthed several fossil specimens in the Chalk Formation, in which he assigned them as Pterodactylus compressirostris during its description.[9] Owen later unearthed many fossil specimens from a different fossil site called the Cambridge Greensand, he then assigned these specimens into a new species called Pterodactylus simus. With the naming of this new species, British paleontologist Harry Govier Seeley created a new separate genus called Ornithocheirus (from Ancient Greek "ὄρνις", meaning "bird", and "χεῖρ", meaning "hand"), due to the notion of the time, in which pterosaurs were the direct ancestors of birds. In 1870, Seeley then also reassigned Pterodactylus cuvieri into a new species called Ornithocheirus cuvieri.[10][11] This species is now considered to belong to the genus Cimoliopterus.[7] Back in 1874 however, controversies between the naming of species and genera of these pterosaurs started, with the paleontologists Harry Seeley and Richard Owen fighting over reassignings of different species as well as genera. Owen therefore created two new genera: Coloborhynchus (meaning "maimed beak") and Criorhynchus (meaning "ram beak"), in reference to their unique convex "keeled" crests on top, and underside of their snout. Owen then created a type species for Coloborhynchus, C. clavirostris, and sunk three species which were assigned previously to Ornithocheirus, and Criorhynchus consisted entirely of former Ornithocheirus species.[12] Later in 1881 however, Seeley disagreed with Owen's conclusions, and he therefore assigned the species he named Ornithocheirus simus as the type species of Ornithocheirus.[13]
Specimen YPM1177, the type specimen of Pteranodon, now interpreted as a female individual due to its short cranial crest
The naming of the different pterosaur species, as well as the genus Ornithocheirus in England resulted in further research in other places. In the United States, American paleontologist Othniel Charles Marsh led an expedition to the Smoky Hill Chalk deposits in western Kansas in 1870.[14] Marsh unearthed the first ever specimens of pterosaur from North America (specimens YPM 1160 and YPM 1161), which now belong to the genus Pteranodon, and consisted of partial wing remains and a tooth of the fish Xiphactinus, which Marsh had once believed that it belonged to Pteranodon.[15] In 1871, he assigned these specimens to a new species called "Pterodactylus oweni" (meaning "Owen's wing finger"),[16] in honor of Sir Richard Owen, but he realized that the name he had chosen had already been used for a different European pterosaur species described by Harry Seeley, so he renamed his discovery as Pterodactylus occidentalis (meaning "Western wing finger"), in reference to the location where it was found.[17] American paleontologist Edward Drinker Cope had also unearthed several remains of the large North American pterosaur, and based on these remains, Cope named two new species, Ornithochirus umbrosus and Ornithochirus harpyia, in an attempt to assign them to the large European genus Ornithocheirus, but he had missed the 'e' when describing them. The paper naming these species by Cope's paper naming had been published in 1872, just five days after the publication of Marsh's paper. This led to a dispute between the two paleontologists, which both fought over whose names had priority to the published literature, in what was obviously the same species of pterosaur.[18]
In 1876, Marsh had described the first skull specimen of Pteranodon, which as unearthed by American paleontologist Samuel Wendell Williston in the Smoky Hill River, located in the Wallace County (now Logan County) of Kansas, USA. Later that year, another skull specimen was found, though this time a bit smaller in size.[19] Soon enough, Marsh recognized a major difference when he described these specimens, they lacked teeth and had bony crests on their skulls. He then described the specimens found as "distinguished from all previously known genera of the order Pterosauria by the entire absence of teeth." Marsh then coined the name Pteranodon (meaning "wing without tooth"), and pointed that the unique characteristics identified warranted a new generic name. Marsh had also reclassified all the previously named North American species from Pterodactylus to Pteranodon, and considered the smaller skull to belong to the reassigned Pteranodon occidentalis based on its size.[19][20] Specimens of smaller individuals were later uncovered, and Marsh had also named several additional species: Pteranodon comptus and Pteranodon nanus, based on these distinct and smaller fragmentary skeletons. He then created another separate species called Pteranodon gracilis, which is now based on a wing bone that he previously mistook for a pelvic bone. Marsh soon realized his mistake, and therefore reassigned that specimen he found into a separate genus which he named Nyctosaurus, and the species P. nanus was soon recognized as a Nyctosaurus specimen as well, this is due to the synapomorphies seen in both.[21][22] Later in 1892, Samuel Williston had become the first scientist to critically evaluate all of the Pteranodon species classified by Cope and Marsh. He agreed with most of Marsh's reassignings and classifications, but several exceptions were still made. Williston revised his earlier conclusion in 1903, in which he stated that there were only three species of Pteranodon, instead of seven. He also considered both P. comptus and P. nanus to be specimens of Nyctosaurus, and divided the other species into small (P. velox), medium (P. occidentalis), and large species (P. ingens), based primarily on the shape of their upper arm bones. He also followed his first conclusion of P. longiceps being a synonym of either P. velox or P. occidentalis based on its size.[23] However, in 1994, Christopher Bennett concluded that P. longiceps and another species called P. sternbergi would be the only valid Pteranodon species, while the other ones were either considered nomina dubia or synonyms.[18]
Skull elements of the specimens NHMUK R3877 and R176 of Istiodactylus, and the 1913 long-jawed skull reconstruction by Reginald Hooley
A peculiar discovery was made in 1887 by Seeley in the Isle of Wight, an island off the coast of southern England. Seeley thought that these fossil remains belonged to bird-like creature, which he then named Ornithodesmus cluniculus.[24] Seeley also reported another specimen found on the same site. Seeley named the new species O. latidens in 1901 based on this discovery, the specific name translates to "wide tooth". He presumably assigned this new species to Ornithodesmus due to synapomorphies between their sacra, but his conclusion was not entirely clear.[25][26] In 1913, English paleontologist Reginald Walter Hooley reviewed O. latidens in detail, based on specimens he had found, and placed the genus Ornithodesmus within a newly created family, Ornithodesmidae.[27][28] Later in 1993, the British paleontologists Stafford C. Howse and Andrew C. Milner concluded that the holotype sacrum and only specimen of the species O. cluniculus didn't belong to a pterosaur, but instead to a maniraptorantheropod dinosaur. They pointed out that no detailed attempts had been made to compare the sacrum of O. cluniculus with those of pterosaurs, and that the species O. latidens had in effect been treated as the type species of the genus Ornithodesmus in their conclusion. Now as a definite species of pterosaur, "O." latidens thus required a new generic name.[26] In 2001, Howse, Milner, and David Martill, reassigned "O." latidens to a new genus called Istiodactylus, resulting in a new combination known as Istiodactylus latidens. The generic name Istiodactylus means "sail finger", in reference to its proportionally large wings.[28]
Classification
Originally defined by Alexander Kellner in 1996, Pteranodontoidea is sometimes considered a synonym of the clade Ornithocheiroidea according to several studies. The name Ornithocheiroidea was originally defined as an apomorphy-based taxon by Christopher Bennett in 1994. In 2003 however, Kellner redefined Ornithocheiroidea to represent the node of Anhanguera, Pteranodon, Quetzalcoatlus and Dsungaripterus, thus making Ornithocheiroidea a more inclusive group.[29] Later that year, David Unwin suggested a different definition, the node that contains Pteranodon longiceps and Istiodactylus latidens, as a resulting, he considered Pteranodontoidea a junior synonym of Ornithocheiroidea.[2] Brian Andres (2008, 2010, 2014) in his analyses, converts Ornithocheiroidea using the definition of Kellner (2003) to avoid this synonymy.[3] In 2013, Andres & Timothy Myers presented a phylogenetic analysis that placed Pteranodontoidea within the group Pteranodontia, as the sister taxon of the family Nyctosauridae.[30] In 2019 however, Kellner and colleagues revisited the classification, and concluded that Pteranodontoidea, which was sister taxon to Tapejaroidea, would be the more inclusive group containing both the Lanceodontia and the Pteranodontia.[31]
Pteranodontoids, like other pterosaurs, are considered to have been skilled fliers as well as adept at moving on the ground. Evidence from footprints shows that most pterosaurs did not sprawl their limbs to a large degree, as in modern reptiles, but rather held the limbs relatively erect when walking, like dinosaurs. While no pteranodontoid footprints are known, it is likely that they also walked erect.[32] Among pterosaurs, pteranodontoids had unusually uneven limb proportions, with the forelimbs much longer than the hind limbs. This would likely have required them to use unique modes of locomotion when on the ground compared to other pterosaurs. It is possible that pteranodontoids ran (but not walked) bipedally, or that they used a hopping gait.[32] Pterosaur researcher Mike Habib has noted that the limbs proportions of pteranodontoids like Anhanguera are consistent with hopping.[33]
Related Research Articles
Pteranodon is a genus of pterosaur that included some of the largest known flying reptiles, with P. longiceps having a wingspan of over 6 m (20 ft). They lived during the late Cretaceous geological period of North America in present-day Kansas, Nebraska, Wyoming, South Dakota and Alabama. More fossil specimens of Pteranodon have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway.
Ornithocheirus is a pterosaur genus known from fragmentary fossil remains uncovered from sediments in the United Kingdom and possibly Morocco.
Tropeognathus is a genus of large pterosaurs from the late Early Cretaceous of South America. This genus is considered to be a member of the family Anhangueridae, however, several studies have also recovered it within another family called Ornithocheiridae. Both of these families are diverse groups of pterosaurs known for their keel-tipped snouts and large size. Tropeognathus is regarded as the largest pterosaur found in the Southern Hemisphere, only rivaled by the huge azhdarchids. The type and only species is Tropeognathus mesembrinus. Fossil remains of Tropeognathus have been recovered from the Romualdo Formation, which is a Lagerstätte located in the Santana Group of the Araripe Basin in northeastern Brazil.
Anhanguera is a genus of pterodactyloid pterosaur known from the Early Cretaceous Romualdo Formation of Brazil and the Late Cretaceous Kem Kem Group of Morocco. This pterosaur is closely related to Ornithocheirus, but belongs in the family Anhangueridae. The generic name comes from the Tupi words añanga, meaning "spirit protector of the animals" + wera "bygone".
Ornithostoma is a genus of pterodactyloid pterosaur that lived during the Early Cretaceous period of Europe, around 110 million years ago. Ornithostoma was once thought to have been a senior synonym of the pteranodontid Pteranodon due to its toothless anatomy and prior naming.
Istiodactylus is a genus of pterosaur that lived during the Early Cretaceous period, about 120 million years ago. The first fossil was discovered on the English Isle of Wight in 1887, and in 1901 became the holotype specimen of a new species, O. latidens, in the genus Ornithodesmus. This species was moved to its own genus, Istiodactylus, in 2001; this name is Greek for "sail finger". More specimens were described in 1913, and Istiodactylus was the only pterosaur known from three-dimensionally preserved fossils for much of the 20th century. In 2006, a species from China, I. sinensis, was assigned to Istiodactylus, but it has also been suggested to belong to a different genus.
Coloborhynchus is a genus of pterodactyloid pterosaur belonging to the family Anhangueridae, though it has also been recovered as a member of the Ornithocheiridae in some studies. Coloborhynchus is known from the Lower Cretaceous of England, and depending on which species are included, possibly the Albian and Cenomanian ages as well. Coloborhynchus was once thought to be the largest known toothed pterosaur, however, a specimen of the closely related Tropeognathus is now thought to have had a larger wingspan.
Nurhachius is a genus of istiodactylid pterodactyloid pterosaur from the Barremian to Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China. Its fossil remains date back about 120 million years ago.
Lonchodectes was a genus of lonchodectid pterosaur from several formations dating to the Turonian of England, mostly in the area around Kent. The species belonging to it had been assigned to Ornithocheirus until David Unwin's work of the 1990s and 2000s. Several potential species are known; most are based on scrappy remains, and have gone through several other generic assignments. The genus is part of the complex taxonomy issues surrounding Early Cretaceous pterosaurs from Brazil and England, such as Amblydectes, Anhanguera, Coloborhynchus, and Ornithocheirus.
Ornithocheiroidea is a group of pterosaurs within the extinct suborder Pterodactyloidea. They were typically large pterosaurs that lived from the Early to Late Cretaceous periods, with fossil remains found all over the world except Antarctica.
Ornithocheiridae is a group of pterosaurs within the suborder Pterodactyloidea. These pterosaurs were among the last to possess teeth. Members that belong to this group lived from the Early to Late Cretaceous periods, around 140 to 90 million years ago.
Istiodactylidae is a small family of pterosaurs. This family was named in 2001 after the type genus Istiodactylus was discovered not to be a member of the genus Ornithodesmus.
Cimoliopterus is a genus of pterosaur that lived during the Late Cretaceous in what is now England and the United States. The first known specimen, consisting of the front part of a snout including part of a crest, was discovered in the Grey Chalk Subgroup of Kent, England, and described as the new species Pterodactylus cuvieri in 1851. The specific name cuvieri honoured the palaeontologist George Cuvier, and the genus Pterodactylus was then used for many pterosaurs of species that are no longer thought to be closely related. It was among the first pterosaurs to be depicted as sculptures, in Crystal Palace Park in the 1850s. The species was subsequently assigned to various other genera, including Ornithocheirus and Anhanguera. In 2013, the species was moved to a new genus, as Cimoliopterus cuvieri; the generic name Cimoliopterus is derived from the Greek words for "chalk" and "wing". Other specimens and species have also been assigned to or synonymised with the species with various levels of certainty. In 2015, a snout discovered in the Britton Formation of Texas, US, was named as a new species in the genus, C. dunni; the specific name honours its collector, Brent Dunn.
Lonchodraco is a genus of lonchodraconid pterodactyloid pterosaur from the Late Cretaceous of southern England. The genus includes species that were previously assigned to other genera.
Camposipterus is a genus of pterodactyloid pterosaur from the Early Cretaceous of England. Fossil remains of Camposipterus dated back to the Early Cretaceous, about 112 million years ago.
Anhangueria is a group of pterosaurs belonging to the clade Pteranodontoidea. Fossil remains of this group date back from the Early to Late Cretaceous periods, around 140 to 92.5 million years ago. Anhangueria was named by paleontologists Taissa Rodrigues and Alexander Kellner in a review of Ornithocheirus species in 2013, they defined the clade as a branch-based taxon consisting of all pteranodontoids more closely related to Anhanguera blittersdorffi than to Istiodactylus latidens and Cimoliopterus cuvieri.
Ikrandraco is a genus of lonchodraconid pterodactyloid pterosaur known from the Lower Cretaceous Jiufotang Formation of northeastern China, and the Cambridge Greensand of England. It is notable for its unusual skull, which features a crest on the lower jaw.
This timeline of pterosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of pterosaurs, the famed flying reptiles of the Mesozoic era. Although pterosaurs went extinct millions of years before humans evolved, humans have coexisted with pterosaur fossils for millennia. Before the development of paleontology as a formal science, these remains would have been interpreted through a mythological lens. Myths about thunderbirds told by the Native Americans of the modern Western United States may have been influenced by observations of Pteranodon fossils. These thunderbirds were said to have warred with water monsters, which agrees well with the co-occurrence of Pteranodon and the ancient marine reptiles of the seaway over which it flew.
Ornithocheiromorpha is a group of pterosaurs within the suborder Pterodactyloidea. Fossil remains of this group date back from the Early to Late Cretaceous periods, around 140 to 92.5 million years ago. Ornithocheiromorphs have been discovered worldwide except Antarctica, though most genera have been recovered in Europe, Asia and South America. They were the most diverse and successful pterosaurs during the Early Cretaceous, but throughout the Late Cretaceous they were replaced by pteranodontians and azhdarchoids. The Ornithocheiromorpha was defined in 2014 by Andres and colleagues, and they made Ornithocheiromorpha the most inclusive clade containing Ornithocheirus, but not Pteranodon.
Aerodraco is a genus of anhanguerid pterosaur from the Albian–Cenomanian-age Cambridge Greensand of England. It contains only one species, Aerodraco sedgwickii. It was originally assigned to the genus Pterodactylus.
References
↑ Richard J. Butler; Stephen L. Brusatte; Brian B. Andres & Roger B. J. Benson (2012). "How do geological sampling biases affect studies of morphological evolution in deep time? A case study of the Pterosauria (Reptilia: Archosauria)". Evolution. 66 (1): 147–162. doi:10.1111/j.1558-5646.2011.01415.x. PMID22220871. S2CID205783384.
1 2 Unwin, D. M., (2003): On the phylogeny and evolutionary history of pterosaurs. pp. 139-190. —in Buffetaut, E. & Mazin, J.-M., (eds.): Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347
↑ Owen, R. (1851). Monograph on the fossil Reptilia of the Cretaceous Formations. The Palaeontographical Society5(11):1-118.
↑ Seeley, H.G., 1869, Index to the fossil remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata, arranged in the Woodwardian Museum of the University of Cambridge. St. John's College, Cambridge 8: 143. doi:10.1080/00222937008696143
↑ Seeley, H.G. (1870). The Ornithosauria: an Elementary Study of the Bones of Pterodactyles. Cambridge, 130 pp.
↑ Owen, R. 1874, Monograph on the fossil Reptilia of the Mesozoic Formations. Palaeontographical Society, London, 14 pp
↑ Betts, C. W. 1871. The Yale College Expedition of 1870. Harper’s New Monthly Magazine, 43(257):663–671
↑ Marsh, O. C. 1871. Scientific expedition to the Rocky Mountains. American Journal of Science, ser. 3, 1(6):142–143.
↑ Marsh, O. C., 1871. "Note on a new and gigantic species of Pterodactyle." American Journal of Science, ser. 3, 1(6):472 oceansofkansas.com/Marsh71.htm
↑ Marsh, O. C. 1872. Discovery of additional remains of Pterosauria, with descriptions of two new species. American Journal of Science, Series 3, 3(16):241–248.
1 2 Bennett, S.C. (1994). "Taxonomy and systematics of the Late Cretaceous pterosaur Pteranodon (Pterosauria, Pterodactyloida)". Occasional Papers of the Natural History Museum, University of Kansas. 169: 1–70.
↑ Bennett, S.C. (2000). "Inferring stratigraphic position of fossil vertebrates from the Niobrara Chalk of western Kansas." Current Research in Earth Sciences: Kansas Geological Survey Bulletin, 244(Part 1): 26 pp.
↑ Witton, M. (2010). Pteranodon and beyond: The history of giant pterosaurs from 1870 onwards. Geological Society of London, Special Publications. 343. 313-323. doi:10.1144/SP343.19
↑ Williston, S. W. 1903. On the osteology of Nyctosaurus (Nyctodactylus), with notes on American pterosaurs. Field Mus. Publ. (Geological Ser.) 2(3):125–163, 2 figs., pls. XL-XLIV.
1 2 Howse, S. C. B.; Milner, A. R.; Martill, D. M. (2001). "Pterosaurs". In Martill, D. M.; Naish, D. (eds.). Dinosaurs of the Isle of Wight. Guide 10; Field Guides to Fossils. London: The Palaeontological Association. pp.324–335. ISBN978-0-901702-72-2.
↑ Kellner, A. W. A., (2003): Pterosaur phylogeny and comments on the evolutionary history of the group. pp. 105-137. —in Buffetaut, E. & Mazin, J.-M., (eds.): Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347
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