123-628: Ornithocheiridae (or ornithocheirids , meaning "bird hands") 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 ( Valanginian to Turonian stages), around 140 to 90 million years ago. Ornithocheirids are generally infamous for having an enormously controversial and very confusing taxonomy. Although agreements that these animals were related, and therefore similar to istiodactylids and pteranodontians , there
246-402: A cusp covering the rear belly, between the pelvis and the belly ribs. The vertical mobility of this element suggests a function in breathing, compensating the relative rigidity of the chest cavity. The hindlimbs of pterosaurs were strongly built, yet relative to their wingspans smaller than those of birds. They were long in comparison to the torso length. The thighbone was rather straight, with
369-424: A different set of relationships for ornithocheirids in their analysis. Within the family, three clades emerge: the first one consists of Ornithocheirus , Tropeognathus and Siroccopteryx , the second one comprises Uktenadactylus with several Coloborhynchus species, and the third one comprises Cimoliopterus and Camposipterus . The close relationship between Siroccopteryx , Ornithocheirus and Tropeognathus
492-458: A few millimetres thin transversely. The bony crest base would typically be extended by keratinous or other soft tissue. Since the 1990s, new discoveries and a more thorough study of old specimens have shown that crests are far more widespread among pterosaurs than previously assumed. That they were extended by or composed completely of keratin, which does not fossilize easily, had misled earlier research. For Pterorhynchus and Pterodactylus ,
615-411: A flying creature in a letter to Georges Cuvier . Cuvier agreed in 1801, understanding it was an extinct flying reptile. In 1809, he coined the name Ptéro-Dactyle , "wing-finger". This was in 1815 Latinised to Pterodactylus . At first most species were assigned to this genus and ultimately "pterodactyl" was popularly and incorrectly applied to all members of Pterosauria. Today, paleontologists limit
738-445: A limited mobility. These toes were clawed but the claws were smaller than the hand claws. The rare conditions that allowed for the fossilisation of pterosaur remains, sometimes also preserved soft tissues. Modern synchrotron or ultraviolet light photography has revealed many traces not visible to the naked eye. These are often imprecisely called "impressions" but mostly consist of petrifications , natural casts and transformations of
861-516: A membrane that stretched between the legs, possibly connecting to or incorporating the tail, called the uropatagium ; the extent of this membrane is not certain, as studies on Sordes seem to suggest that it simply connected the legs but did not involve the tail (rendering it a cruropatagium ). A common interpretation is that non-pterodactyloid pterosaurs had a broader uro/cruropatagium stretched between their long fifth toes, with pterodactyloids, lacking such toes, only having membranes running along
984-425: A new fossil of Tupandactylus cf. imperator was found to have melanosomes in forms that signal an earlier-than-anticipated development of patterns found in extant feathers. The new specimen suggested that pterosaur integumentary melanosomes exhibited a more complex organization than those previously known from other pterosaurs. This indicates the presence of a unique form of melanosomes within pterosaur integument at
1107-466: A result, they perhaps influenced the later pteranodontids with the same piscivorous diet, as well as their well-developed flight techniques. Analyses of limb proportions in the genus Anhanguera , however, show that some ornithocheirids were consistent with hopping, but the later genera were suggested that they most likely walked on four limbs, which consists on their wing-fingers as the front limbs, and using their hind limbs to balance. Ornithocheirids were
1230-411: A rotation could be caused by an abduction of the thighbone, meaning that the legs would be spread. This would also turn the feet into a vertical position. They then could act as rudders to control yaw. Some specimens show membranes between the toes, allowing them to function as flight control surfaces. The uropatagium or cruropatagium would control pitch. When walking the toes could flex upwards to lift
1353-460: A specimen that belongs to the species Coloborhynchus capito , the largest toothed pterosaur, had a wingspan that may have reached 7 meters (23 ft). However, in 2013, a specimen referred to the genus Tropeognathus (MN 6594-V), a possible ornithocheirid (as it may be an anhanguerid), was calculated to have had a normal wingspan of 8.26 meters (27.1 ft), with another calculated maximum wingspan reached 8.70 meters (28.5 ft), indicating that
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#17327649847891476-595: A study by Borja Holgado and Pêgas had also recovered both Ferrodraco and Mythunga within the Anhangueridae instead of this family. Cimoliopterus has generally been recovered outside the Ornithocheiridae; subsequent analyses have found it as sister taxon to Aetodactylus , as mentioned earlier. Another possible position for Cimoliopterus is within the clade Targaryendraconia, again, closely related to Aetodactylus , and together with Camposipterus ,
1599-449: A supraneural plate that, however, would not contact the notarium. The tails of pterosaurs were always rather slender. This means that the caudofemoralis retractor muscle which in most basal Archosauria provides the main propulsive force for the hindlimb, was relatively unimportant. The tail vertebrae were amphicoelous, the vertebral bodies on both ends being concave. Early species had long tails, containing up to fifty caudal vertebrae,
1722-464: A thousand bristle-like teeth. Dsungaripteridae covered their teeth with jawbone tissue for a crushing function. If teeth were present, they were placed in separate tooth sockets. Replacement teeth were generated behind, not below, the older teeth. The public image of pterosaurs is defined by their elaborate head crests. This was influenced by the distinctive backward-pointing crest of the well-known Pteranodon . The main positions of such crests are
1845-416: A unique, complex circulatory system of looping blood vessels. The combination of actinofibrils and muscle layers may have allowed the animal to adjust the wing slackness and camber . As shown by cavities in the wing bones of larger species and soft tissue preserved in at least one specimen, some pterosaurs extended their system of respiratory air sacs into the wing membrane. The pterosaur wing membrane
1968-408: A weight of up to 250 kilograms (550 pounds) for the largest species. Compared to the other vertebrate flying groups, the birds and bats, pterosaur skulls were typically quite large. Most pterosaur skulls had elongated jaws. Their skull bones tend to be fused in adult individuals. Early pterosaurs often had heterodont teeth, varying in build, and some still had teeth in the palate. In later groups
2091-453: A wide range of adult sizes , from the very small anurognathids to the largest known flying creatures, including Quetzalcoatlus and Hatzegopteryx , which reached wingspans of at least nine metres. The combination of endothermy , a good oxygen supply and strong muscles made pterosaurs powerful and capable flyers. Pterosaurs are often referred to by popular media or the general public as "flying dinosaurs", but dinosaurs are defined as
2214-605: A widespread type of pterosaur, with many fossil remains found across the world. The first true ornithocheirid specimens were uncovered in the Cambridge Greensand of England , belonging to the infamous genus Ornithocheirus , and dated back to the Albian stage of the Early Cretaceous. Within the fossil site, several other pterosaurs were also found, including the pterosaurs Amblydectes and Coloborhynchus ,
2337-482: A wingspan no less than 25 centimetres (10 inches). The most sizeable forms represent the largest known animals ever to fly, with wingspans of up to 10–11 metres (33–36 feet). Standing, such giants could reach the height of a modern giraffe . Traditionally, it was assumed that pterosaurs were extremely light relative to their size. Later, it was understood that this would imply unrealistically low densities of their soft tissues. Some modern estimates therefore extrapolate
2460-555: Is common in warm-blooded animals who need insulation to prevent excessive heat-loss. Pycnofibers were flexible, short filaments, about five to seven millimetres long and rather simple in structure with a hollow central canal. Pterosaur pelts might have been comparable in density to many Mesozoic mammals. Pterosaur filaments could share a common origin with feathers, as speculated in 2002 by Czerkas and Ji. In 2009, Kellner concluded that pycnofibers were structured similarly to theropod proto-feathers . Others were unconvinced, considering
2583-422: Is curved to behind, resulting in a rounded wing tip, which reduces induced drag . The wingfinger is also bent somewhat downwards. When standing, pterosaurs probably rested on their metacarpals, with the outer wing folded to behind. In this position, the "anterior" sides of the metacarpals were rotated to the rear. This would point the smaller fingers obliquely to behind. According to Bennett, this would imply that
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#17327649847892706-421: Is divided into three basic units. The first, called the propatagium ("fore membrane"), was the forward-most part of the wing and attached between the wrist and shoulder, creating the "leading edge" during flight. The brachiopatagium ("arm membrane") was the primary component of the wing, stretching from the highly elongated fourth finger of the hand to the hindlimbs. Finally, at least some pterosaur groups had
2829-438: Is recovered as a separate and distinct family from Ornithocheiridae, each containing different genera. The original term Ornithocheirae by Seeley had been redefined as the least inclusive clade containing Anhanguera blittersdorffi and Ornithocheirus simus , therefore it is recovered as a larger group comprising the families Anhangueridae and Ornithocheiridae in recent analysis. In the past, many pterosaur genera were assigned to
2952-418: Is short but powerfully built. It sports a large deltopectoral crest, to which the major flight muscles are attached. Despite the considerable forces exerted on it, the humerus is hollow or pneumatised inside, reinforced by bone struts. The long bones of the lower arm, the ulna and radius , are much longer than the humerus. They were probably incapable of pronation . A bone unique to pterosaurs, known as
3075-495: Is still no virtual consensus over the exact content and interrelationships of this group. Ornithocheirids were the most successful pterosaurs during their reign, and were also the largest pterosaurs before the appearance of the azhdarchids such as Quetzalcoatlus . Ornithocheirids were excellent fish hunters, using various flight techniques to catch their prey, and were also capable of flying great distances without flapping constantly. Paleontologists suspect that ornithocheirids were
3198-713: Is supported by a number of anatomical features. The elongated rostra of ornithocheirids are considered ideal for reaching into the water to grab swimming creatures; the rostral crests of ornithocheirids would have worked well as stabilizers for the jaws tips while being plunged into the water. Large, forward-facing eyes and well-developed flocculi are ideal for dip-feeding as well, which permits effective spotting of prey as well as judgement of distances when striking at them; as such, it seems likely that at least several ornithocheirids were efficient dip feeders. Sedate foraging methods might have also been used when hunting -- examples of these methods are: reaching food while being alighted on
3321-411: Is supported by several synapomorphies, such the teeth being short, straight, and relatively uniform in size. Several other recent studies such as the ones by Alexander Kellner and colleagues, or the one by Rodrigo Pêgas and colleagues, both in 2019, have recovered Coloborhynchus , Siroccopteryx , Tropeognathus and Uktenadactylus within the family Anhangueridae instead of the Ornithocheiridae. In 2020,
3444-494: Is that the teeth are short, straight, and relatively uniform in size, something that is not present in other ornithocheirans such as Coloborhynchus and Anhanguera . In Coloborhynchus , the teeth were found to have been heterodont , elongated, recurved and caniniform , which is similar to those seen in another ornithocheirid (though also recovered as an anhanguerid) called Caulkicephalus . The genus Caulkicephalus , though having similarities with other ornithocheirids, including
3567-656: The Gault Formation and the Chalk Group in the vicinity of Cambridgeshire , and technically forms the lowest member bed of the West Melbury Marly Chalk Formation. It is a remanié deposit, containing reworked fossils of late Albian age, including those of dinosaurs and pterosaurs. The lithology is made out of glauconitic marl , described as a "chalk mud", containing abundant ostracod , coccolith and foram remains, with
3690-612: The Lanceodontia in several recent studies such as the ones by Rodrigo Pêgas and colleagues, and Adele Pentland and colleagues, both studies of which are from 2019. Aetodactylus is another pterosaur that was initially classified within the Ornithocheiridae; later analysis have found it outside the Ornithocheiridae: Timothy Myers in 2015 and Nicholas Longrich and colleagues in 2018 for example, are two studies that found Aetodactylus as sister taxon to
3813-776: The Mesozoic : from the Late Triassic to the end of the Cretaceous (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight . Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger. There were two major types of pterosaurs. Basal pterosaurs (also called 'non-pterodactyloid pterosaurs' or ' rhamphorhynchoids ') were smaller animals with fully toothed jaws and, typically, long tails. Their wide wing membranes probably included and connected
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3936-477: The patagium , and the presence of both aktinofibrils and filaments on Jeholopterus ningchengensis and Sordes pilosus . The various forms of filament structure present on the anurognathids in the 2018 study would also require a form of decomposition that would cause the different 'filament' forms seen. They therefore conclude that the most parsimonious interpretation of the structures is that they are filamentous protofeathers. But Liliana D'Alba points out that
4059-512: The premaxilla having a tall and narrow shape in anterior aspect, the anterolateral margins of the premaxilla being convex in both anterior and lateral view, a feature that resulted in a bluntly rounded outline of the tip of the rostrum. The rostrum in S. moroccensis lacks a constriction that is posterior to the anterior rosette, a feature also shared by O. simus and T. mesembrinus , therefore another synapomorphy supported by these three species. Yet another feature shared by these three species
4182-578: The sacrum develops a supraneural plate above its neural spines . The tails of ornithocheirids are poorly known, though they appear to be composed of at least eleven short vertebrae , and become relatively circular in cross section toward the end of the series. Like the related istiodactylids , the slender femora of ornithocheirids have femoral heads that project almost in line with the femoral shaft , but seem to lack prominent processes that anchor their hindlimb muscles. Ornithocheirid shinbones (or tibiae) are similarly developed and of equal length to
4305-427: The thorax . It was probably covered by thick muscle layers. The upper bone, the shoulder blade , was a straight bar. It was connected to a lower bone, the coracoid that is relatively long in pterosaurs. In advanced species, their combined whole, the scapulocoracoid, was almost vertically oriented. The shoulder blade in that case fitted into a recess in the side of the notarium, while the coracoid likewise connected to
4428-461: The "bat model" depicted pterosaurs as warm-blooded and furred, it would turn out to be more correct in certain aspects than Cuvier's "reptile model" in the long run. In 1834, Johann Jakob Kaup coined the term Pterosauria. Cambridge Greensand The Cambridge Greensand is a geological unit in England whose strata are earliest Cenomanian in age. It lies above the erosive contact between
4551-428: The 1990s, pterosaur finds and histological and ultraviolet examination of pterosaur specimens have provided incontrovertible proof: pterosaurs had pycnofiber coats. Sordes pilosus (which translates as "hairy demon") and Jeholopterus ninchengensis show pycnofibers on the head and body. The presence of pycnofibers strongly indicates that pterosaurs were endothermic (warm-blooded). They aided thermoregulation, as
4674-429: The 2014 analysis by Andres and colleagues instead. Other studies such as the ones by Kellner and colleagues in 2019 have used a different concept, classifying Coloborhynchus , Tropeognathus , as well as several other close relatives such as Ludodactylus and Caulkicephalus within the Anhangueridae, which, along with the family Hamipteridae , forms the larger group Anhangueria . They assigned Ornithocheirus outside
4797-594: The Anhangueria due to being undiagnosable. Most recent studies have since followed this concept. Among toothed pterodactyloids , ornithocheirids were the largest; they were also among the most successful and widely distributed pterosaurs. Ornithocheirids were characterized by long jaws with spike-like teeth. Ornithocheirid wingspans varied in size, with smaller species having wingspans of approximately 4 meters (13 ft), while giant morphs reached wingspans of up to 8 meters (26 ft) or more. Specimen NHMUK R481,
4920-424: The Early Cretaceous. The Romualdo Formation is found to contain a variety of ornithocheirids (or anhanguerids), including Tropeognathus , Coloborhynchus and Araripesaurus , the targaryendraconian Barbosania as well as close relatives such as Anhanguera and Maaradactylus . The related Araripedactylus , Brasileodactylus , Cearadactylus , Santanadactylus and Unwindia were also present within
5043-686: The Ornithocheiridae besides a note added in proof to Unwin in 2001 that stated that Haopterus appeared to be a small ornithocheirid. Phylogenetic analyses since then have found Haopterus as a rogue taxon either within the Pterodactyloidea, the Ornithocheiroidea, the Pteranodontoidea , or the Istiodactylidae . In the phylogenetic analysis by Andres and Myers, Haopterus was recovered as a stable sister taxon to
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5166-488: The Ornithocheiridae to comprise more genera; while the typical Tropeognathus , Coloborhynchus and Ornithocheirus clade was included in their analysis, Pentland and colleagues found the genera Ferrodraco and Mythunga to belong the Ornithocheiridae as well, specifically sister taxa within the Ornithocheirinae, closely related to Ornithocheirus . In the same year, Megan Jacobs and colleagues have recovered
5289-503: The Ornithocheiridae, but some recent analysis have placed it within the more inclusive group Anhangueria , outside the Ornithocheiridae. Other studies, however, have recovered it within the Anhangueridae instead. The forelimbs of ornithocheirids were proportionally enormous, around five times longer than their legs. Substantial anchorage on the body is required given the mighty arms, and accordingly, ornithocheirids have robust scapulocoracoids , and stout, deeply keeled sterna , which served
5412-435: The Ornithocheiridae; however, following recent studies, these supposed ornithocheirids had been reclassified to other groups or families. The pterosaur Boreopterus for example, was initially classified within the Ornithocheiridae; however, later analysis had found it in a different family called Boreopteridae , with Boreopterus being the sister taxon of Zhenyuanopterus ; both pterosaurs were recovered as basal members of
5535-573: The addition of a new species called C. clavirostris ; no type species was designated, however. In 1876, however, Seeley pointed out that Criorhynchus was a junior synonym of Ornithocheirus , a concept that was followed by paleontologist Richard Lydekker in 1888. In the latter year, Lydekker acknowledged that Ornithocheirus simus was the type species of Ornithocheirus , and also distinguished O. simus by its tall rostrum , while other species referred to Ornithocheirus had lanceolate jaw tips. Therefore, to avoid confusion, Lydekker preferred to use
5658-662: The ancestors of the pteranodontians ; this is due to many shared aspects, such as unique flying techniques, capability of long-distance flights, and most of their diet, which mainly consisted of fish. The family Ornithocheiridae is without a doubt, one of the most well-known pterosaur groups, mostly due to their very controversial and convoluted taxonomic history. Most of the ornithocheirid fossil record consists of isolated teeth, as well as fragmentary bones, reaching hundreds or even thousands of remains in some localities. The first uncovered ornithocheirid remains were described in 1861 by British paleontologist Sir Richard Owen , who assigned
5781-428: The ankle, sometimes reducing total length to a third. Typically, it was fused to the shinbone. The ankle was a simple, "mesotarsal", hinge. The, rather long and slender, metatarsus was always splayed to some degree. The foot was plantigrade, meaning that during the walking cycle the sole of the metatarsus was pressed onto the soil. There was a clear difference between early pterosaurs and advanced species regarding
5904-484: The ankles. The exact curvature of the trailing edge, however, is still equivocal. While historically thought of as simple leathery structures composed of skin, research has since shown that the wing membranes of pterosaurs were highly complex dynamic structures suited to an active style of flight. The outer wings (from the tip to the elbow) were strengthened by closely spaced fibers called actinofibrils . The actinofibrils themselves consisted of three distinct layers in
6027-470: The anterior end of the rostrum being transversely expanded, or having a low, bony sagittal crest that includes a smooth dorsal margin on the rostrum, still possesses some unique features. The most distinct characteristic of Caulkicephalus is that it bores a frontoparietal crest, a feature that is only seen in pteranodontians such as Pteranodon , and in Ludodactylus , a pterosaur once assigned to
6150-427: The anterior surface of the distal syncarpal. The medial carpal bears a deep concave fovea that opens anteriorly, ventrally and somewhat medially, within which the pteroid articulates, according to Wilkinson. In derived pterodactyloids like pteranodontians and azhdarchoids , metacarpals I-III are small and do not connect to the carpus, instead hanging in contact with the fourth metacarpal. With these derived species,
6273-413: The breastbone. This way, both sides together made for a rigid closed loop, able to withstand considerable forces. A peculiarity was that the breastbone connections of the coracoids often were asymmetrical, with one coracoid attached in front of the other. In advanced species the shoulder joint had moved from the shoulder blade to the coracoid. The joint was saddle-shaped and allowed considerable movement to
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#17327649847896396-447: The broad ischium into an ischiopubic blade. Sometimes, the blades of both sides were also fused, closing the pelvis from below and forming the pelvic canal. The hip joint was not perforated and allowed considerable mobility to the leg. It was directed obliquely upwards, preventing a perfectly vertical position of the leg. The front of the pubic bones articulated with a unique structure, the paired prepubic bones. Together these formed
6519-474: The clade Anurognathidae ( Anurognathus , Jeholopterus , Vesperopterylus ) is debated. Anurognathids were highly specialized. Small flyers with shortened jaws and a wide gape, some had large eyes suggesting nocturnal or crepuscular habits, mouth bristles, and feet adapted for clinging. Parallel adaptations are seen in birds and bats that prey on insects in flight. Pterosaurs had a wide range of sizes, though they were generally large. The smallest species had
6642-445: The clades Ornithocheiroidea ( Istiodactylus , Ornithocheirus , Pteranodon ), Ctenochasmatoidea ( Ctenochasma , Pterodactylus ), Dsungaripteroidea ( Germanodactylus , Dsungaripterus ), and Azhdarchoidea ( Tapejara , Tupuxuara , Quetzalcoatlus ). The two groups overlapped in time, but the earliest pterosaurs in the fossil record are basal pterosaurs, and the latest pterosaurs are pterodactyloids. The position of
6765-502: The descendants of the last common ancestor of the Saurischia and Ornithischia , which excludes the pterosaurs. Pterosaurs are nonetheless more closely related to birds and other dinosaurs than to crocodiles or any other living reptile, though they are not bird ancestors. Pterosaurs are also colloquially referred to as pterodactyls , particularly in fiction and journalism. However, technically, pterodactyl may refer to members of
6888-431: The description of the preserved integumentary structures on the two anurognathid specimens is still based upon gross morphology. She also points out that Pterorhynchus was described to have feathers to support the claim that feathers had a common origin with Ornithodirans but was argued against by several authors. The only method to assure if it was homologous to feathers is to use a scanning electron microscope. In 2022,
7011-474: The description of the pterosaur Mimodactylus , Haopterus , which was assigned to this family by Unwin, and recovered as a basal eupterodactyloid by Brian Andres and colleagues, was reassigned by Alexander Kellner and colleagues as the sister taxon of the former. In 2014, Andres and colleagues defined the Ornithocheiridae with a different definition: the most inclusive clade containing Ornithocheirus simus but not Anhanguera blittersdorffi . They placed
7134-544: The difference with the "quills" found on many of the bird-like maniraptoran specimens too fundamental. A 2018 study of the remains of two small Jurassic -age pterosaurs from Inner Mongolia , China , found that pterosaurs had a wide array of pycnofiber shapes and structures, as opposed to the homogeneous structures that had generally been assumed to cover them. Some of these had frayed ends, very similar in structure to four different feather types known from birds or other dinosaurs but almost never known from pterosaurs prior to
7257-410: The down feathers found on both avian and some non-avian dinosaurs , suggesting that early feathers evolved in the common ancestor of pterosaurs and dinosaurs, possibly as insulation. They were warm-blooded (endothermic), active animals. The respiratory system had efficient unidirectional "flow-through" breathing using air sacs , which hollowed out their bones to an extreme extent. Pterosaurs spanned
7380-404: The extent of their wing membranes and it is possible that, like these groups, different species of pterosaur had different wing designs. Indeed, analysis of pterosaur limb proportions shows that there was considerable variation, possibly reflecting a variety of wing-plans. The bony elements of the arm formed a mechanism to support and extend the wing. Near the body, the humerus or upper arm bone
7503-676: The feather-specific melanosome signaling found in extant birds are possibly homologous with those found in pterosaurs. Pterosaur fossils are very rare, due to their light bone construction. Complete skeletons can generally only be found in geological layers with exceptional preservation conditions, the so-called Lagerstätten . The pieces from one such Lagerstätte , the Late Jurassic Solnhofen Limestone in Bavaria , became much sought after by rich collectors. In 1784, Italian naturalist Cosimo Alessandro Collini
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#17327649847897626-419: The femora. Although the feet in ornithocheirids are poorly known, they seem to be relatively small and gracile, with undeveloped claws and a hook-like fifth metatarsal . The family Ornithocheiridae has had a controversial and very confusing taxonomic history; paleontologists who have studied this group seem to have had a different opinion on the composition of ornithocheirid taxonomy. A term called Anhangueridae
7749-432: The fifth toes as hooks. Another hypothesis held that they stretched the brachiopatagia, but in articulated fossils the fifth digits are always flexed towards the tail. Later it became popular to assume that these toes extended an uropatagium or cruropatagium between them. As the fifth toes were on the outside of the feet, such a configuration would only have been possible if these rotated their fronts outwards in flight. Such
7872-450: The forces caused by flapping the wings. The notarium included three to seven vertebrae, depending on the species involved but also on individual age. These vertebrae could be connected by tendons or a fusion of their neural spines into a "supraneural plate". Their ribs also would be tightly fused into the notarium. In general, the ribs are double headed. The sacrum consisted of three to ten sacral vertebrae. They too, could be connected via
7995-400: The forelimb digits besides the wingfinger have been lost altogether. The wingfinger accounts for about half or more of the total wing length. It normally consists of four phalanges. Their relative lengths tend to vary among species, which has often been used to distinguish related forms. The fourth phalanx is usually the shortest. It lacks a claw and has been lost completely by nyctosaurids. It
8118-417: The form of the fifth digit. Originally, the fifth metatarsal was robust and not very shortened. It was connected to the ankle in a higher position than the other metatarsals. It bore a long, and often curved, mobile clawless fifth toe consisting of two phalanges. The function of this element has been enigmatic. It used to be thought that the animals slept upside-down like bats, hanging from branches and using
8241-424: The formation, with some specimens referred to the genera Santanachelys , Cearachelys and Araripemys . Many fish remains were also found, assigned to the genera Brannerion , Rhinobatos , Rhacolepis , Tharrhias and Tribodus . Pterosaur Ornithosauria Seeley , 1870 Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria . They existed during most of
8364-471: The fossil remains to a new species of Pterodactylus : P. simus . In 1869, British paleontologist Harry Govier Seeley erected the new generic name Ornithocheirus (from Ancient Greek meaning "bird hand"), and assigned P. simus as its type species, therefore creating Ornithocheirus simus . Later, in 1870, Seeley created the name Ornithocheirae to only contain Ornithocheirus . However, in
8487-412: The fossil site. Many other pterosaur were found within, including the tapejarid Tapejara , as well as the thalassodromids (or thalassodromines, depending on the author) Thalassodromeus and Tupuxuara . Other animals such the theropods Irritator , Mirischia and Santanaraptor , as well as the crocodylomorph Araripesuchus were also found. Several turtle remains were found within
8610-415: The fourth metacarpal has been enormously elongated, typically equalling or exceeding the length of the long bones of the lower arm. The fifth metacarpal had been lost. In all species, the first to third fingers are much smaller than the fourth, the "wingfinger", and contain two, three and four phalanges respectively. The smaller fingers are clawed, with the ungual size varying among species. In nyctosaurids
8733-473: The front of the snout, as an outgrowth of the premaxillae, or the rear of the skull as an extension of the parietal bones in which case it is called a "supraoccipital crest". Front and rear crests can be present simultaneously and might be fused into a single larger structure, the most expansive of which is shown by the Tapejaridae . Nyctosaurus sported a bizarre antler-like crest. The crests were only
8856-524: The genera Coloborhynchus , Ornithocheirus and Tropeognathus within the Ornithocheiridae, while placing Anhanguera within the separate family Anhangueridae . However, back in 2001, Unwin considered the name Anhangueridae a junior synonym of Ornithocheiridae, a concept that was later followed by several paleontologists such as Mark Witton in 2013. Some phylogenetic analyses , however, contradict this name synonymy, with Ornithocheiridae and Anhangueridae classified as different families, therefore following
8979-429: The genus Pterodactylus , and more broadly to members of the suborder Pterodactyloidea of the pterosaurs. Pterosaurs had a variety of lifestyles. Traditionally seen as fish-eaters, the group is now understood to have also included hunters of land animals, insectivores, fruit eaters and even predators of other pterosaurs. They reproduced by eggs , some fossils of which have been discovered. The anatomy of pterosaurs
9102-683: The ground, they walked well on all four limbs with an upright posture, standing plantigrade on the hind feet and folding the wing finger upward to walk on the three-fingered "hand". They could take off from the ground, and fossil trackways show that at least some species were able to run, wade, and/or swim. Their jaws had horny beaks, and some groups lacked teeth. Some groups developed elaborate head crests with sexual dimorphism . Pterosaurs sported coats of hair-like filaments known as pycnofibers , which covered their bodies and parts of their wings. Pycnofibers grew in several forms, from simple filaments to branching down feathers . These may be homologous to
9225-490: The group Ornithocheiroidea. Some later analyses have also recovered this concept, with both Haopterus and the Ornithocheiroidea placed within the larger group Eupterodactyloidea. Another study in 2019 recovered Haopterus within a different group called Mimodactylidae . Different phylogenetic analysis have found Ornithocheiridae to comprise different genera, the most typical ones being Tropeognathus , Coloborhynchus and Ornithocheirus . In 2014, Andres and colleagues created
9348-464: The head and torso. The term "pycnofiber", meaning "dense filament", was coined by palaeontologist Alexander Kellner and colleagues in 2009. Pycnofibers were unique structures similar to, but not homologous (sharing a common origin) with, mammalian hair, an example of convergent evolution . A fuzzy integument was first reported from a specimen of Scaphognathus crassirostris in 1831 by Georg August Goldfuss , but had been widely doubted. Since
9471-412: The head making only a small angle with the shaft. This implies that the legs were not held vertically below the body but were somewhat sprawling. The shinbone was often fused with the upper ankle bones into a tibiotarsus that was longer than the thighbone. It could attain a vertical position when walking. The calf bone tended to be slender, especially at its lower end that in advanced forms did not reach
9594-478: The hind legs. On the ground, they would have had an awkward sprawling posture, but the anatomy of their joints and strong claws would have made them effective climbers, and some may have even lived in trees. Basal pterosaurs were insectivores or predators of small vertebrates. Later pterosaurs ( pterodactyloids ) evolved many sizes, shapes, and lifestyles. Pterodactyloids had narrower wings with free hind limbs, highly reduced tails, and long necks with large heads. On
9717-401: The jaw joint was in a more forward position. The front lower jaw bones, the dentaries or ossa dentalia , were at the tip tightly fused into a central symphysis. This made the lower jaws function as a single connected whole, the mandible . The symphysis was often very thin transversely and long, accounting for a considerable part of the jaw length, up to 60%. If a crest was present on the snout,
9840-547: The legs. There has been considerable argument among paleontologists about whether the main wing membranes (brachiopatagia) attached to the hindlimbs, and if so, where. Fossils of the rhamphorhynchoid Sordes , the anurognathid Jeholopterus , and a pterodactyloid from the Santana Formation seem to demonstrate that the wing membrane did attach to the hindlimbs, at least in some species. However, modern bats and flying squirrels show considerable variation in
9963-1334: The limited number of characters that can be scored, and the levels of homoplasy are very high. Below are two cladograms showing the possible genera that are included within the ornithocheirid family. The cladogram to the left is a topology recovered by Jacobs and colleagues, and the one to the right is a topology recovered by Pentland and colleagues. Topology 1: Jacobs et al. (2019). Anhangueridae Coloborhynchus clavirostris Uktenadactylus wadleighi Coloborhynchus reedi Coloborhynchus capito Coloborhynchus fluviferox Coloborhynchus NHMUK R481 Siroccopteryx moroccensis Ornithocheirus simus Tropeognathus mesembrinus Camposipterus segwickii Camposipterus colorhinus Camposipterus nasutus Cimoliopterus cuvieri Cimoliopterus dunni Topology 2: Pentland et al. (2019). Guidraco Brasileodactylus Ludodactylus Cearadactylus Liaoningopterus Anhanguera Tropeognathus Coloborhynchus Ornithocheirus Ferrodraco Mythunga Ornithocheirids are generally considered piscivorous animals, mainly because they seem to have been suited for flight over marine settings; in fact, most ornithocheirids are known from lagoonal, coastal and marine deposits. Although
10086-482: The manner in which ornithocheirids gathered their food has not been researched in detail, it is generally thought that members of this family either fed like modern-day skimmers , pushing their lower jaw through the water to snap up food upon impact, or fed by gleaning food from the water surface like some modern-day terns and frigatebirds . The skim-feeding hypothesis on ornithocheirids has been discounted in recent assessments of pterosaur skim-feeding, while dip-feeding
10209-402: The membrane from the ground. In Pterodactyloidea, the fifth metatarsal was much reduced and the fifth toe, if present, little more than a stub. This suggests that their membranes were split, increasing flight maneuverability. The first to fourth toes were long. They had two, three, four and five phalanges respectively. Often the third toe was longest; sometimes the fourth. Flat joints indicate
10332-421: The middle ones stiffened by elongated articulation processes, the zygapophyses , and chevrons . Such tails acted as rudders, sometimes ending at the rear in a vertical diamond-shaped or oval vane. In pterodactyloids, the tails were much reduced and never stiffened, with some species counting as few as ten vertebrae. The shoulder girdle was a strong structure that transferred the forces of flapping flight to
10455-478: The name Criorhynchus for O. simus , and Ornithocheirus for the species with lanceolate jaw tips, a concept later favored by paleontologist Reginald Walter Hooley in 1914. In his review of Ornithocheirus , he divided the family Ornithocheiridae into two subfamilies: Ornithocheirinae and Criorhynchinae; the former consisted of Ornithocheirus and Lonchodectes , while the latter consisted of Amblydectes and Criorhynchus . In his review, Hooley also considered
10578-575: The neck is typically longer than the torso. This length is not caused by an increase of the number of vertebrae, which is invariably seven. Some researchers include two transitional "cervicodorsals" which brings the number to nine. Instead, the vertebrae themselves became more elongated, up to eight times longer than wide. Nevertheless, the cervicals were wider than high, implying a better vertical than horizontal neck mobility. Pterodactyloids have lost all neck ribs. Pterosaur necks were probably rather thick and well-muscled, especially vertically. The torso
10701-458: The original material. They may include horn crests, beaks or claw sheaths as well as the various flight membranes. Exceptionally, muscles were preserved. Skin patches show small round non-overlapping scales on the soles of the feet, the ankles and the ends of the metatarsals . They covered pads cushioning the impact of walking. Scales are unknown from other parts of the body. Most or all pterosaurs had hair -like filaments known as pycnofibers on
10824-405: The pteroid bone, which may itself be a modified distal carpal. The proximal carpals are fused together into a "syncarpal" in mature specimens, while three of the distal carpals fuse to form a distal syncarpal. The remaining distal carpal, referred to here as the medial carpal, but which has also been termed the distal lateral, or pre-axial carpal, articulates on a vertically elongate biconvex facet on
10947-402: The pteroid in articulation with the proximal syncarpal, suggesting that the pteroid articulated with the 'saddle' of the radiale (proximal syncarpal) and that both the pteroid and preaxial carpal were migrated centralia. The pterosaur wrist consists of two inner (proximal, at the side of the long bones of the arm) and four outer (distal, at the side of the hand) carpals (wrist bones), excluding
11070-441: The pteroid pointed forward, extending the forward membrane and allowing it to function as an adjustable flap . This view was contradicted in a 2007 paper by Chris Bennett, who showed that the pteroid did not articulate as previously thought and could not have pointed forward, but rather was directed inward toward the body as traditionally interpreted. Specimens of Changchengopterus pani and Darwinopterus linglongtaensis show
11193-488: The pteroid, connected to the wrist and helped to support the forward membrane (the propatagium) between the wrist and shoulder. Evidence of webbing between the three free fingers of the pterosaur forelimb suggests that this forward membrane may have been more extensive than the simple pteroid-to-shoulder connection traditionally depicted in life restorations. The position of the pteroid bone itself has been controversial. Some scientists, notably Matthew Wilkinson, have argued that
11316-455: The purpose of housing their substantial forelimb muscles. The shoulder or pectoral girdle in ornithocheirids is set at a perpendicular angle to the spine, with the coracoids being much longer than the scapulae . The shoulder girdle is also of typical construction for ornithocheiroids . Over 60 percent of the wing length is occupied by the wing fingers, making them among the longest possessed by any pterodactyloids . In adult ornithocheirids,
11439-609: The remains of ornithocheirids. A Lagerstätte called the Santana Group (sometimes known as the Santana Formation) in northeastern Brazil was found to contain a large number of pterosaur genera. The most diverse formation of the group is the Romualdo Formation, known for its wide variety of pterosaur remains. The formation dates back around 111 to 108 million years ago, also during the Albian stage of
11562-598: The same year, this was emended to Ornithocheiridae by Seeley himself following the article 11.7.1.3 of the ICZN . In 1874, Owen had proposed two new genera for the Cretaceous British pterosaurs: Coloborhynchus (meaning "maimed beak") and Criorhynchus (meaning "ram beak") based on highly distinctive jaw fragments. Owen reassigned P. simus as the type species of Criorhynchus , creating Criorhynchus simus . He referred three species to Coloborhynchus , including
11685-586: The skull, the sutures between elements disappeared. In some later pterosaurs, the backbone over the shoulders fused into a structure known as a notarium , which served to stiffen the torso during flight, and provide a stable support for the shoulder blade . Likewise, the sacral vertebrae could form a single synsacrum while the pelvic bones fused also. Basal pterosaurs include the clades Dimorphodontidae ( Dimorphodon ), Campylognathididae ( Eudimorphodon , Campyognathoides ), and Rhamphorhynchidae ( Rhamphorhynchus , Scaphognathus ). Pterodactyloids include
11808-461: The species Coloborhynchus clavirostris as a synonym of Criorhynchus simus . In 1967, paleontologist Oskar Kuhn placed Criorhynchus within the family Criorhynchidae (which is now considered synonymous to Ornithocheiridae), and recognized Ornithocheirus within the family Ornithocheiridae and subfamily Ornithocheirinae. He also designated the species Coloborhynchus clavirostris as the type species of Coloborhynchus , but agreed with Hooley that it
11931-400: The study, suggesting homology. A response to this study was published in 2020, where it was suggested that the structures seen on the anurognathids were actually a result of the decomposition of aktinofibrils: a type of fibre used to strengthen and stiffen the wing. However, in a response to this, the authors of the 2018 paper point to the fact that the presence of the structures extend past
12054-501: The subfamily Ornithocheirinae to contain Coloborhynchus and Ornithocheirus , as a sister taxon to Tropeognathus , and altogether formed the family Ornithocheiridae. In 2018, Longrich and colleagues had included the genus Siroccopteryx in their phylogenetic analysis, specifically as a member of the ornithocheirine subfamily, sister taxon to Coloborhynchus . In 2019, a study performed by Adele Pentland and colleagues had found
12177-405: The symphysis could feature a matching mandible crest, jutting out to below. Toothed species also bore teeth in their dentaries. The mandible opened and closed in a simple vertical or "orthal" up-and-down movement. The vertebral column of pterosaurs numbered between thirty-four and seventy vertebrae . The vertebrae in front of the tail were "procoelous": the cotyle (front of the vertebral body )
12300-477: The targaryendraconian Camposipterus , the lonchodraconid Lonchodraco , and the azhdarchoid Ornithostoma . The ornithischians Anoplosaurus , Acanthopholis , and the dubious Eucercosaurus and Trachodon were also found within the formation. Fossil remains of the sauropod Macrurosaurus were also present. The bird Enaliornis , as well as the ichthyosaurs Cetarthrosaurus , Platypterygius and Sisteronia were also found alongside
12423-405: The teeth mostly became conical. Front teeth were often longer, forming a "prey grab" in transversely expanded jaw tips, but size and position were very variable among species. With the derived Pterodactyloidea , the skulls became even more elongated, sometimes surpassing the combined neck and torso in length. This was caused by a stretching and fusion of the front snout bone, the premaxilla , with
12546-480: The term to the genus Pterodactylus or members of the Pterodactyloidea . In 1812 and 1817, Samuel Thomas von Soemmerring redescribed the original specimen and an additional one. He saw them as affiliated to birds and bats. Although he was mistaken in this, his "bat model" would be influential during the 19th century. In 1843, Edward Newman thought pterosaurs were flying marsupials . Ironically, as
12669-410: The three formed the family Cimoliopteridae. In the analysis by Jacobs and colleagues, the two Cimoliopterus species had been found as sister taxa to the three Camposipterus species ( C. nasutus , C. colorhinus and C. segwickii ), altogether formed an unnamed clade within the Ornithocheiridae. However, as noted by Jacobs and colleagues, support for some of these arrangements is relatively weak due to
12792-453: The time, distinct from previously known contemporary integumentary structures and more similar to those reported from mammalian hair and avian feathers. The feather fossils obtained from this specimen also suggest the presence of Stage IIIa feathers, a new discovery that indicates more complex feather structures were present in pterosaurs. The study describing this specimen further clarifies the timeline of avian feather evolution and suggests that
12915-422: The true extent of these crests has only been uncovered using ultraviolet photography. While fossil crests used to be restricted to the more advanced Pterodactyloidea, Pterorhynchus and Austriadactylus show that even some early pterosaurs possessed them. Like the upper jaws, the paired lower jaws of pterosaurs were very elongated. In advanced forms, they tended to be shorter than the upper cranium because
13038-544: The two species of Cimoliopterus ( C. cuvieri and C. dunni ). In 2019, Pêgas and colleagues have found Aetodactylus , along with two other pterosaurs ( Camposipterus and Cimoliopterus ), within the clade Targaryendraconia , more specifically placed within the family Cimoliopteridae in a polytomy . The genus Haopterus was used to define the Ornithocheiridae in Unwin's 2003 study; however, Andres and Myers in 2013 argued that Haopterus had not been previously referred to
13161-594: The type and only species of Ornithocheirus . In 2003, Unwin defined the family Ornithocheiridae as Haopterus gracilis , Ornithocheirus simus , their most recent common ancestor , and all its descendants. He included the genera Anhanguera , Brasileodactylus , Coloborhynchus , Haopterus , Ludodactylus and Ornithocheirus within the family, and also concluded that Araripesaurus , Arthurdactylus and Santanadactylus may belong to this family as well. However, their taxonomic status and precise relationships with other ornithocheirids are uncertain. In 2019, upon
13284-416: The upper jawbone, the maxilla . Unlike most archosaurs , the nasal and antorbital openings of pterodactyloid pterosaurs merged into a single large opening, called the nasoantorbital fenestra . This feature likely evolved to lighten the skull for flight. In contrast, the bones behind the eye socket contracted and rotated, strongly inclining the rear skull and bringing the jaw joint forward. The braincase
13407-757: The water surface, and shallow surface dives. Similar to modern-day albatrosses, most ornithocheirids used a flight technique called " dynamic soaring ", which consists of travelling long distances without flapping using the vertical gradient of wind speed near the ocean surface as an advantage, at moderate flight speed. Several studies showed that most ornithocheirids sprawled their limbs to a large degree, similar to crocodiles, while other studies conclude that ornithocheirids were generally quadrupedal. Yet other studies concluded that ornithocheirids held their limbs more or less vertically extended, similar to an avian or mammalian configuration. Some studies in later genera show that ornithocheirids spend much of their time at sea, and as
13530-416: The wing, forming a crisscross pattern when superimposed on one another. The function of the actinofibrils is unknown, as is the exact material from which they were made. Depending on their exact composition (keratin, muscle, elastic structures, etc.), they may have been stiffening or strengthening agents in the outer part of the wing. The wing membranes also contained a thin layer of muscle, fibrous tissue, and
13653-402: The wing. It faced sideways and somewhat upwards. The breastbone, formed by fused paired sterna , was wide. It had only a shallow keel. Via sternal ribs, it was at its sides attached to the dorsal ribs. At its rear, a row of belly ribs or gastralia was present, covering the entire belly. To the front, a long point, the cristospina , jutted obliquely upwards. The rear edge of the breastbone
13776-475: The wingfinger, able to describe the largest arc of any wing element, up to 175°, was not folded by flexion but by an extreme extension. The wing was automatically folded when the elbow was bowed. A laser-simulated fluorescence scan on Pterodactylus also identified a membranous "fairing" (area conjunctioning the wing with the body at the neck), as opposed to the feathered or fur-composed "fairing" seen in birds and bats respectively. The pelvis of pterosaurs
13899-522: The wingspans of toothed pterosaurs could exceed 7 meters (23 ft). Ornithocheirids had elongated jaws with rounded sagittal crests on both tips, as well as robust fang-like teeth. The sagittal crest of the species Ornithocheirus simus and Tropeognathus mesembrinus extended to the anterior end of the rostrum , a feature that is also seen in the ornithocheirid (or alternately anhanguerid) species Siroccopteryx moroccensis ; further synapomorphies between these three species were also found, including
14022-412: Was coined by Diogenes de Almeida Campos and Kellner in 1985 to refer to pterosaurs that belong in this family. In 2001, however, Unwin argued that the name Ornithocheiridae refers to an identical group, and should have nomenclatural priority. He therefore considered Anhangueridae a junior synonym of Ornithocheiridae in his study of pterosaur phylogeny in 2003. However, in many recent studies, Anhangueridae
14145-401: Was concave and into it fitted a convex extension at the rear of the preceding vertebra, the condyle . Advanced pterosaurs are unique in possessing special processes projecting adjacent to their condyle and cotyle, the exapophyses , and the cotyle also may possess a small prong on its midline called a hypapophysis. The necks of pterosaurs were relatively long and straight. In pterodactyloids,
14268-451: Was highly modified from their reptilian ancestors by the adaptation to flight. Pterosaur bones were hollow and air-filled, like those of birds . This provided a higher muscle attachment surface for a given skeletal weight. The bone walls were often paper-thin. They had a large and keeled breastbone for flight muscles and an enlarged brain able to coordinate complex flying behaviour. Pterosaur skeletons often show considerable fusion. In
14391-407: Was of moderate size compared to the body as a whole. Often the three pelvic bones were fused. The ilium was long and low, its front and rear blades projecting horizontally beyond the edges of the lower pelvic bones. Despite this length, the rod-like form of these processes indicates that the hindlimb muscles attached to them were limited in strength. The, in side view narrow, pubic bone fused with
14514-643: Was relatively large for reptiles. In some cases, fossilized keratinous beak tissue has been preserved, though in toothed forms, the beak is small and restricted to the jaw tips and does not involve the teeth. Some advanced beaked forms were toothless, such as the Pteranodontidae and Azhdarchidae , and had larger, more extensive, and more bird-like beaks. Some groups had specialised tooth forms. The Istiodactylidae had recurved teeth for eating meat. Ctenochasmatidae used combs of numerous needle-like teeth for filter feeding; Pterodaustro could have over
14637-403: Was relatively short and egg-shaped. The vertebrae in the back of pterosaurs originally might have numbered eighteen. With advanced species a growing number of these tended to be incorporated into the sacrum . Such species also often show a fusion of the front dorsal vertebrae into a rigid whole which is called the notarium after a comparable structure in birds. This was an adaptation to withstand
14760-482: Was synonymous with Criorhynchus simus . In 1994, however, Yuong-Nam Lee revalidated the genus Coloborhynchus (with C. clavirostris as its type species), and regarded it as distinct from Criorhynchus simus . Later, in 2001, paleontologist David Unwin revised the taxonomic history of the Cambridge Greensand pterosaurs, and divided Ornithocheiridae into three genera: Ornithocheirus , Coloborhynchus and Anhanguera . Unwin also designated Ornithocheirus simus as
14883-482: Was that if such creatures were still alive, only the sea was a credible habitat; Collini suggested it might be a swimming animal that used its long front limbs as paddles. A few scientists continued to support the aquatic interpretation even until 1830, when German zoologist Johann Georg Wagler suggested that Pterodactylus used its wings as flippers and was affiliated with Ichthyosauria and Plesiosauria . In 1800, Johann Hermann first suggested that it represented
15006-456: Was the deepest point of the thorax. Clavicles or interclavicles were completely absent. Pterosaur wings were formed by bones and membranes of skin and other tissues. The primary membranes attached to the extremely long fourth finger of each arm and extended along the sides of the body. Where they ended has been very controversial but since the 1990s a dozen specimens with preserved soft tissue have been found that seem to show they attached to
15129-400: Was the first scientist to describe a pterosaur fossil. At that time the concepts of evolution and extinction were imperfectly developed. The bizarre build of the pterosaur was shocking, as it could not clearly be assigned to any existing animal group. The discovery of pterosaurs would thus play an important role in the progress of modern paleontology and geology. Scientific opinion at the time
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