Pterosaur

Pterosaurs Temporal range: Ma PreꞒ Ꞓ O S D C P T J K Pg N
A sample of various pterosaurs.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Ornithodira
Clade:	†Pterosauromorpha
Order:	†Pterosauria Owen, 1842
Subgroups[1][2]
†Caviramidae †Eopterosauria †Preondactylia †Preondactylus †Austriadactylus †Macronychoptera †Eudimorphodon? †Peteinosaurus? † Dimorphodontia †Novialoidea
Distribution of pterosaur fossil locations. Colored species or genera names correspond to their taxonomic group.[a]
Synonyms
Pterosaurii Kaup, 1834 Ornithosauria Seeley , 1870

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.

Description

The anatomy of pterosaurs was highly modified from their reptilian ancestors by the adaptation to flight. Pterosaur

Basal pterosaurs include the clades Dimorphodontidae (Dimorphodon), Campylognathididae (Eudimorphodon, Campyognathoides), and Rhamphorhynchidae (Rhamphorhynchus, Scaphognathus).

Pterodactyloids include the clades Ornithocheiroidea (

The two groups overlapped in time, but the earliest pterosaurs in the fossil record are basal pterosaurs, and the latest pterosaurs are pterodactyloids.[19]

The position of the clade Anurognathidae (

habits, mouth bristles, and feet adapted for clinging. Parallel adaptations are seen in birds and bats that prey on insects in flight.

Size

Main article: Pterosaur size

Pterosaurs had a wide range of sizes, though they were generally large. The smallest species had a wingspan no less than 25 centimetres (10 inches).^[12] The most sizeable forms represent the largest known animals ever to fly, with wingspans of up to 10–11 metres (33–36 feet).^[21]

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 a weight of up to 250 kilograms (550 pounds) for the largest species.^[22]

Skull, teeth, and crests

Compared to the other vertebrate flying groups, the birds and bats, pterosaur skulls were typically quite large.

braincase was relatively large for reptiles.^[28]

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.^[29] Some advanced beaked forms were toothless, such as the Pteranodontidae and Azhdarchidae, and had larger, more extensive, and more bird-like beaks.^[24] 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 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.^[26] Replacement teeth were generated behind, not below, the older teeth.^[25]

The public image of pterosaurs is defined by their elaborate head crests.^[30] This was influenced by the distinctive backward-pointing crest of the well-known Pteranodon. The main positions of such crests are 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".^[28] 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 a few millimetres thin transversely. The bony crest base would typically be extended by keratinous or other soft tissue.^[28]

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.^[31] For Pterorhynchus and Pterodactylus, the true extent of these crests has only been uncovered using ultraviolet photography.^[29][32] While fossil crests used to be restricted to the more advanced Pterodactyloidea, Pterorhynchus and Austriadactylus show that even some early pterosaurs possessed them.^[31]

Like the upper jaws, the paired lower jaws of pterosaurs were very elongated.^[33] In advanced forms, they tended to be shorter than the upper cranium because 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%.^[27] If a crest was present on the snout, the symphysis could feature a matching mandible crest, jutting out to below.^[27] Toothed species also bore teeth in their dentaries. The mandible opened and closed in a simple vertical or "orthal" up-and-down movement.

Vertebral column

The

The necks of pterosaurs were relatively long and straight. In pterodactyloids, the neck is typically longer than the torso.^[36] 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.^[36] 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.^[35] Pterosaur necks were probably rather thick and well-muscled,^[37] especially vertically.^[38]

The torso 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

The tails of pterosaurs were always rather slender. This means that the

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.[41] At its rear, a row of belly ribs or gastralia was present, covering the entire belly.^[42] To the front, a long point, the cristospina, jutted obliquely upwards. The rear edge of the breastbone was the deepest point of the thorax.^[44] Clavicles or interclavicles were completely absent.^[42]

Wings

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 the ankles. The exact curvature of the trailing edge, however, is still equivocal.^[45]

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 pterosaur wing membrane is divided into three basic units.^[50] 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 a membrane that stretched between the legs, possibly connecting to or incorporating the tail, called the uropatagium;^[50] 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 the legs.^[51]

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

The bony elements of the arm formed a mechanism to support and extend the wing. Near the body, the

pronation

.

A bone unique to pterosaurs,[58] known as 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.^[31] The position of the pteroid bone itself has been controversial. Some scientists, notably Matthew Wilkinson, have argued that the pteroid pointed forward, extending the forward membrane and allowing it to function as an adjustable flap.^[59] 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.^[60] Specimens of Changchengopterus pani and Darwinopterus linglongtaensis show 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.^[61][62]

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 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 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.^[63]

In derived pterodactyloids like

induced drag. The wingfinger is also bent somewhat downwards.^[65]

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 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.[38]^[66]

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.^[67]

Pelvis

The

hip joint was not perforated and allowed considerable mobility to the leg.^[64] It was directed obliquely upwards, preventing a perfectly vertical position of the leg.^[65]

The front of the pubic bones articulated with a unique structure, the paired prepubic bones. Together these formed 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.[64]

Hindlimbs

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.

metatarsus was always splayed to some degree.^[70] The foot was plantigrade, meaning that during the walking cycle the sole of the metatarsus was pressed onto the soil.^[69]

There was a clear difference between early pterosaurs and advanced species regarding the form of the fifth digit. Originally, the fifth

abduction of the thighbone, meaning that the legs would be spread. This would also turn the feet into a vertical position.^[69] They then could act as rudders to control yaw. Some specimens show membranes between the toes,^[71] allowing them to function as flight control surfaces. The uropatagium or cruropatagium would control pitch. When walking the toes could flex upwards to lift the membrane from the ground. In Pterodactyloidea, the fifth metatarsal was much reduced and the fifth toe, if present, little more than a stub.^[72] This suggests that their membranes were split, increasing flight maneuverability.^[51]

The first to fourth toes were long. They had two, three, four and five phalanges respectively.[68] Often the third toe was longest; sometimes the fourth. Flat joints indicate a limited mobility. These toes were clawed but the claws were smaller than the hand claws.^[70]

Soft tissues

The rare conditions that allowed for the fossilisation of pterosaur remains, sometimes also preserved soft tissues. Modern

petrifications, natural casts and transformations of the original material. They may include horn crests, beaks or claw sheaths as well as the various flight membranes. Exceptionally, muscles were preserved.^[74] Skin patches show small round non-overlapping scales on the soles of the feet, the ankles and the ends of the metatarsals.^[75] They covered pads cushioning the impact of walking. Scales are unknown from other parts of the body.^[76]

Pycnofibers

Most or all pterosaurs had

The presence of pycnofibers strongly indicates that pterosaurs were endothermic (warm-blooded). They aided thermoregulation, as is common in warm-blooded animals who need insulation to prevent excessive heat-loss.^[77] Pycnofibers were flexible, short filaments, about five to seven millimetres long and rather simple in structure with a hollow central canal.^[77] Pterosaur pelts might have been comparable in density to many Mesozoic mammals.^[b][77]

Relation with feathers

Pterosaur filaments could share a common origin with feathers, as speculated in 2002 by Czerkas and Ji.

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 the study, suggesting homology.^[79][80] 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.^[81] However, in a response to this, the authors of the 2018 paper point to the fact that the presence of the structures extend past the patagium, and the presence of both aktinofibrils and filaments on Jeholopterus ningchengensis^[82] and Sordes pilosus.^[83] 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.^[84] But Liliana D'Alba points out that the description of the preserved integumentary structures on the two anurogmathid 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.^[85]

In 2022, a new fossil of Tupandactylus cf. imperator^[86] was found to have melanosomes in forms that signal an earlier than anticipated development of the patterns found in extant feathers than previously thought. In these fossils, it appears as though the feather melanosomes took on a more complex form than the melanosome organization in scales that near relatives of Tupandactylus had. This discovery is one of many that leads us away from many previous theories of feathers evolving directly from scales in reptiles, given the significant distinction of melanosome organization and content between the two. This indicates a distinct form of melanosomes within feather structures at the time, different from other contemporary feathers that did not carry this formation. The feather fossils obtained from this specimen also suggested the presence of Stage IIIa feathers, a new discovery which may also suggest that more complex feather structures were present at this time. Previously, no Stage III feather forms had been discovered in this time. This study contains multiple indications about the development of feather forms. These include a more precise estimate for the development of avian feather forms, as well as a more ancient ancestor that contained the origins of feather-specific melanosome signaling found in extant birds.

History of discovery

First finds

In 1800, Johann Hermann first suggested that it represented a flying creature in a letter to Georges Cuvier. Cuvier agreed in 1801, understanding it was an extinct flying reptile.^[94] In 1809, he coined the name Ptéro-Dactyle, "wing-finger".^[95] This was in 1815 Latinised to Pterodactylus.^[96] At first most species were assigned to this genus and ultimately "pterodactyl" was popularly and incorrectly applied to all members of Pterosauria.^[16] Today, paleontologists limit the term to the genus Pterodactylus or members of the Pterodactyloidea.^[17]

In 1812 and 1817,

In 1828,

The situation for dinosaurs was comparable. From the 1960s onwards, a

Evolution and extinction

Origins

anatomical and neuroanatomical

similarities with pterosaurs.

Because pterosaur

tanystropheids. A placement among basal archosauriforms like Euparkeria was also suggested.^[24] Some basal archosauromorphs seem at first glance to be good candidates for close pterosaur relatives due to their long-limbed anatomy; one example is Sharovipteryx, a "protorosaur" with skin membranes on its hindlimbs likely used for gliding.^[128] A 1999 study by Michael Benton found that pterosaurs were avemetatarsalians closely related to Scleromochlus, and named the group Ornithodira to encompass pterosaurs and dinosaurs.^[129]

archosauromorph

theorized to be related to pterosaurs.

Two researchers, S. Christopher Bennett in 1996,

sensory systems based on CT scans also showing neuroanatomical similarities with pterosaurs.^[137][138] The results of the latter study were subsequently supported by an independent analysis of early pterosauromorph interrelationships.^[139]

A related problem is the origin of pterosaur flight.

selection pressure for incipient flight.^{[clarification needed]} Rupert Wild in 1983 proposed a hypothetical "propterosaurus": a lizard-like arboreal animal developing a membrane between its limbs, first to safely parachute and then, gradually elongating the fourth finger, to glide.^[141] However, subsequent cladistic results did not fit this model well. Neither protorosaurs nor ornithodirans are biologically equivalent to lizards. Furthermore, the transition between gliding and flapping flight is not well-understood. More recent studies on basal pterosaur hindlimb morphology seem to vindicate a connection to Scleromochlus. Like this archosaur, basal pterosaur lineages have plantigrade hindlimbs that show adaptations for saltation.^[142]

At least one study found that the early Triassic

ichnofossil Prorotodactylus is anatomically similar to that of early pterosaurs.^[136]

Extinction

It was once thought that competition with early

extinction of many of the pterosaurs.^[143] It was thought that by the end of the Cretaceous, only large species of pterosaurs were present (no longer true; see below). The smaller species were thought to have become extinct, their niche filled by birds.^[144] However, pterosaur decline (if actually present) seems unrelated to bird diversity, as ecological overlap between the two groups appears to be minimal.^[145] In fact, at least some avian niches were reclaimed by pterosaurs prior to the Cretaceous–Paleogene extinction event.^[146]

At the end of the Cretaceous period, the K-Pg extinction event, which wiped out all non-avian dinosaurs and most avian dinosaurs as well, and many other animals, seems also to have taken the pterosaurs.

In the early 2010s, several new pterosaur taxa were discovered dating to the Campanian/Maastrichtian, such as the ornithocheirids Piksi and "Ornithocheirus", possible pteranodontids and nyctosaurids, several tapejarids and the indeterminate non-azhdarchid Navajodactylus.^[147][148] Small azhdarchoid pterosaurs were also present in the Campanian. This suggests that late Cretaceous pterosaur faunas were far more diverse than previously thought, possibly not even having declined significantly from the early Cretaceous.

Small-sized pterosaur species apparently were present in the

dinosaurs, and that their diversity might actually have been much larger than previously thought.^[150]

At least some non-pterodactyloid pterosaurs survived into the Late Cretaceous, postulating a Lazarus taxa situation for late Cretaceous pterosaur faunas.^[151]

A 2021 study showcases that niches previously occupied by small pterosaurs were increasingly occupied by the juvenile stages of larger species in the Late Cretaceous. Rather than outcompeted by birds, pterosaurs essentially specialized a trend already occurring in previous eras of the Mesozoic.^[152]

Classification and phylogeny

Further information:

List of pterosaur classifications

In

ornithodirans more closely related to pterosaurs than to dinosaurs.^[156]

The internal

paraphyletic (unnatural) group, since the pterodactyloids evolved directly from them and not from a common ancestor, so, with the increasing use of cladistics, it has fallen out of favor among most scientists.^[124][157]

The precise relationships between pterosaurs is still unsettled. Many studies of pterosaur relationships in the past have included limited data and were highly contradictory. However, newer studies using larger data sets are beginning to make things clearer. The

phylogenetic analysis presented by Longrich, Martill and Andres in 2018, with clade names after Andres et al. (2014).^[146][1]

Pterosauria

Eopterosauria Macronychoptera Dimorphodontia Campylognathoididae Rhamphorhynchidae Sordes Darwinoptera Changchengopterus Anurognathidae Pterodactyloidea Kryptodrakon Lophocratia Archaeopterodactyloidea Germanodactylidae Euctenochasmatia Pterodactylus Ctenochasmatoidea Eupterodactyloidea Haopterus Ornithocheiroidea Azhdarchoidea Tapejaromorpha Neoazhdarchia Piksi Pteranodontoidea Pteranodontia Ornithocheiromorpha Caelidracones Pterodactyliformes Monofenestrata Pterodactylomorpha Breviquartossa Novialoidea

Paleobiology

Flight

The mechanics of pterosaur flight are not completely understood or modeled at this time.^{[158][159][needs update]}

Katsufumi Sato, a Japanese scientist, did calculations using modern birds and concluded that it was impossible for a pterosaur to stay aloft.^[158] In the book Posture, Locomotion, and Paleoecology of Pterosaurs it is theorized that they were able to fly due to the oxygen-rich, dense atmosphere of the Late Cretaceous period.^[160] However, both Sato and the authors of Posture, Locomotion, and Paleoecology of Pterosaurs based their research on the now-outdated theories of pterosaurs being seabird-like, and the size limit does not apply to terrestrial pterosaurs, such as azhdarchids and tapejarids. Furthermore, Darren Naish concluded that atmospheric differences between the present and the Mesozoic were not needed for the giant size of pterosaurs.^[161]

Another issue that has been difficult to understand is how they

Mark Witton of the University of Portsmouth and Mike Habib of Johns Hopkins University suggested that pterosaurs used a vaulting mechanism to obtain flight.^[163] The tremendous power of their winged forelimbs would enable them to take off with ease.^[162] Once aloft, pterosaurs could reach speeds of up to 120 km/h (75 mph) and travel thousands of kilometres.^[163]

In 1985, the Smithsonian Institution commissioned aeronautical engineer

Large-headed species are thought to have forwardly swept their wings in order to better balance.^[166]

Air sacs and respiration

A 2009 study showed that pterosaurs had a lung-and-air-sac system and a precisely controlled skeletal breathing pump, which supports a flow-through pulmonary ventilation model in pterosaurs, analogous to that of birds. The presence of a subcutaneous air sac system in at least some pterodactyloids would have further reduced the density of the living animal.^[49] Like modern crocodilians, pterosaurs appeared to have had a hepatic piston, seeing as their shoulder-pectoral girdles were too inflexible to move the sternum as in birds, and they possessed strong gastralia.^[167] Thus, their respiratory system had characteristics comparable to both modern archosaur clades.

Nervous system

An X-ray study of pterosaur

Pterosaurs' hip sockets are oriented facing slightly upwards, and the head of the femur (thigh bone) is only moderately inward facing, suggesting that pterosaurs had an erect stance. It would have been possible to lift the thigh into a horizontal position during flight, as gliding lizards do.

There was considerable debate whether pterosaurs ambulated as

Fossil footprints show that pterosaurs stood with the entire foot in contact with the ground (plantigrade), in a manner similar to many mammals like humans and bears. Footprints from azhdarchids and several unidentified species show that pterosaurs walked with an erect posture with their four limbs held almost vertically beneath the body, an energy-efficient stance used by most modern birds and mammals, rather than the sprawled limbs of modern reptiles.^[71][162] Indeed, erect-limbs may be omnipresent in pterosaurs.^[142]

Though traditionally depicted as ungainly and awkward when on the ground, the anatomy of some pterosaurs (particularly pterodactyloids) suggests that they were competent walkers and runners.

The forelimb bones of azhdarchids and ornithocheirids were unusually long compared to other pterosaurs, and, in azhdarchids, the bones of the arm and hand (metacarpals) were particularly elongated. Furthermore, as a whole, azhdarchid front limbs were proportioned similarly to fast-running ungulate mammals. Their hind limbs, on the other hand, were not built for speed, but they were long compared with most pterosaurs, and allowed for a long stride length. While azhdarchid pterosaurs probably could not run, they would have been relatively fast and energy efficient.^[71]

The relative size of the hands and feet in pterosaurs (by comparison with modern animals such as birds) may indicate the type of lifestyle pterosaurs led on the ground. Azhdarchid pterosaurs had relatively small feet compared to their body size and leg length, with foot length only about 25–30% the length of the lower leg. This suggests that azhdarchids were better adapted to walking on dry, relatively solid ground. Pteranodon had slightly larger feet (47% the length of the tibia), while filter-feeding pterosaurs like the ctenochasmatoids had very large feet (69% of tibial length in Pterodactylus, 84% in Pterodaustro), adapted to walking in soft muddy soil, similar to modern wading birds.^[71] Though clearly forelimb-based launchers, basal pterosaurs have hindlimbs well adapted for hopping, suggesting a connection with archosaurs such as Scleromochlus.^[142]

Swimming

Tracks made by ctenochasmatoids indicate that these pterosaurs swam using their hindlimbs. In general, these have large hindfeet and long torsos, indicating that they were probably more adapted for swimming than other pterosaurs.

While very little is known about pterosaur reproduction, it is believed that, similar to all dinosaurs, all pterosaurs reproduced by laying eggs, though such findings are very rare. The first known pterosaur egg was found in the quarries of Liaoning, the same place that yielded feathered dinosaurs. The egg was squashed flat with no signs of cracking, so evidently the eggs had leathery shells, as in modern lizards.^[193] This was supported by the description of an additional pterosaur egg belonging to the genus Darwinopterus, described in 2011, which also had a leathery shell and, also like modern reptiles but unlike birds, was fairly small compared to the size of the mother.^[194] In 2014 five unflattened eggs from the species Hamipterus tianshanensis were found in an Early Cretaceous deposit in northwest China. Examination of the shells by scanning electron microscopy showed the presence of a thin calcareous eggshell layer with a membrane underneath.^[195] A study of pterosaur eggshell structure and chemistry published in 2007 indicated that it is likely pterosaurs buried their eggs, like modern crocodiles and turtles. Egg-burying would have been beneficial to the early evolution of pterosaurs, as it allows for more weight-reducing adaptations, but this method of reproduction would also have put limits on the variety of environments pterosaurs could live in and may have disadvantaged them when they began to face ecological competition from birds.^[196]

A Darwinopterus specimen showcases that at least some pterosaurs had a pair of functional

A 2021 study indicates that pterosaur juveniles of larger species increasingly took the roles previously occupied by adult small pterosaurs.[152]

Daily activity patterns

Comparisons between the

Pterosaurs have been a staple of popular culture for as long as their cousins the dinosaurs, though they are usually not featured as prominently in films, literature or other art. While the depiction of dinosaurs in popular media has changed radically in response to advances in paleontology, a mainly outdated picture of pterosaurs has persisted since the mid-20th century.^[208]

The vague generic term "pterodactyl" is often used for these creatures. The animals depicted in fiction and pop culture frequently represent either the

Pterosaurs were used in fiction in Sir Arthur Conan Doyle's 1912 novel The Lost World and its 1925 film adaptation. They appeared in a number of films and television programs since, including the 1933 film King Kong, and 1966's One Million Years B.C. In the latter, animator Ray Harryhausen had to add inaccurate bat-like wing fingers to his stop motion models in order to keep the membranes from falling apart, though this particular error was common in art even before the film was made. Rodan, a fictional giant monster (or kaiju) which first appeared in the 1956 film Rodan, is portrayed as an enormous irradiated species of Pteranodon.^[210][211] Rodan has appeared in multiple Japanese Godzilla films released during the 1960s, 1970s, 1990s, and 2000s, and also appeared in the 2019 American-produced film Godzilla: King of the Monsters.^{[212][213][211]}

After the 1960s, pterosaurs remained mostly absent from notable American film appearances until 2001's Jurassic Park III. Paleontologist Dave Hone noted that the pterosaurs in this film had not been significantly updated to reflect modern research. Errors persisting were teeth while toothless Pteranodon was intended to be depicted, nesting behavior that was known to be inaccurate by 2001, and leathery wings, rather than the taut membranes of muscle fiber required for pterosaur flight.^[208] Petrie from The Land Before Time (1988), is a notable example from an animated film.^[214]

In most media appearances, pterosaurs are depicted as

• Flying and gliding animals
• Graphical timeline of pterosaurs
• List of pterosaur-bearing stratigraphic units
• List of pterosaur genera
• Phylogeny of pterosaurs
• Pterosaur Beach
• Pterosaur size
• Timeline of pterosaur research

Explanatory notes

References

1. ^
   PMID 24768054
   .
2. PMID 33005485
   .
3. ISBN 978-0-691-15061-1
4. ^ David M. Unwin (2010), "Darwinopterus and its implications for pterosaur phylogeny", Acta Geoscientica Sinica, 31 (1): 68–69
5. ISBN 978-3-12-539683-8
6. ^ "Pterosaur". Merriam-Webster.com Dictionary.
7. ^ Colbert, Edwin H. (Edwin Harris); Knight, Charles Robert (1951). The dinosaur book: the ruling reptiles and their relatives. New York: McGraw-Hill. p. 153.
8. ^ "Pterosaur distribution in time and space: an atlas" (PDF). Zitteliana: 61–107. 2008.
9. doi:10.4202/app.2009.0145
   .
10. ^ "Pterosaur.net :: Terrestrial Locomotion". pterosaur.net. Retrieved 2020-02-01.
11. ^ Geggel 2018-12-17T19:23:17Z, Laura (17 December 2018). "It's Official: Those Flying Reptiles Called Pterosaurs Were Covered in Fluffy Feathers". livescience.com. Retrieved 2020-02-01.{{cite web}}: CS1 maint: numeric names: authors list (link)
12. ^
    PMID 18268340
    .
13. S2CID 46396417
    .
14. S2CID 15423666
    .
15. ISBN 978-0-520-24209-8
    .
16. ^ ^{a b c} Naish, Darren. "Pterosaurs: Myths and Misconceptions". Pterosaur.net. Retrieved June 18, 2011.
17. ^
    ISBN 978-0-8018-8059-9
    .
18. ^
    S2CID 4431861
    .
19. ^ "Pterosaur.net :: Origins and Relationships". pterosaur.net. Retrieved 2020-02-01.
20. S2CID 53688256
    .
21. ^ Witton, Mark P.; Martill, David M.; Loveridge, Robert F. (2010). "Clipping the Wings of Giant Pterosaurs: Comments on Wingspan Estimations and Diversity". Acta Geoscientica Sinica. 31: 79–81.
22. ^ Witton 2013, p. 58.
23. ^ ^{a b c} Witton 2013, p. 23.
24. ^
    ISBN 978-0-13-146308-0
    .
25. ^ ^{a b} Witton 2013, p. 27.
26. ^ ^{a b} Wellnhofer 1991, p. 47.
27. ^ ^{a b c} Witton 2013, p. 26.
28. ^ ^{a b c} Witton 2013, p. 24.
29. ^
    doi:10.1127/njgpa/210/1998/421
    .
30. ^ Wellnhofer 1991, p. 48.
31. ^ ^{a b c d} Naish D, Martill DM (2003). "Pterosaurs – a successful invasion of prehistoric skies". Biologist. 50 (5): 213–16.
32. ^
    ISBN 1-932075-01-1
    .
33. ^ Wellnhofer 1991, p. 49.
34. ^ S. Christopher Bennett (1994). "Taxonomy and systematics of the Late Cretaceous pterosaur Pteranodon (Pterosauria, Pterodactyloidea)". Occasional Papers of the Natural History Museum of the University of Kansas. 169: 1–70.
35. ^ ^{a b} Witton 2013, p. 28.
36. ^ ^{a b c} Wellnhofer 1991, p. 50.
37. ^ Witton 2013, p. 45.
38. ^ ^{a b c d} Witton 2013, p. 46.
39. ^ ^{a b c} Witton 2013, p. 30.
40. ^ ^{a b c} Witton 2013, p. 31.
41. ^ ^{a b} Wellnhofer 1991, p. 51.
42. ^ ^{a b c d e} Wellnhofer 1991, p. 52.
43. ^ Witton 2013, p. 44.
44. ^ ^{a b c} Witton 2013, p. 32.
45. ^ Witton 2013, p. 54.
46. ^ ^{a b} Witton 2013, p. 53.
47. S2CID 85185457
    .
48. ^
    PMID 19656798
    .
49. ^
    PMID 19223979
    .
50. ^ ^{a b} Witton 2013, p. 52.
51. ^ ^{a b} Witton 2013, p. 55.
52. ^
    S2CID 4314989
    .
53. S2CID 86641794
    .
54. S2CID 130462931
    .
55. S2CID 30516133
    .
56. ^ ^{a b c} Wellnhofer 1991, p. 53.
57. ^ Witton 2013, p. 33.
58. ^ Witton 2013, p. 34.
59. PMID 16519243
    .
60. S2CID 86326537
    .
61. doi:10.1127/0077-7749/2011/0131
    .
62. PMID 21152776
    .
63. PMID 16519243
    .
64. ^ ^{a b c d e f g h} Witton 2013, p. 35.
65. ^ ^{a b c d} Wellnhofer 1991, p. 55.
66. ^ Wellnhofer 1991, pp. 53–54.
67. S2CID 239028043
    .
68. ^ ^{a b c d e f} Wellnhofer 1991, p. 56.
69. ^ ^{a b c d e f} Wellnhofer 1991, p. 57.
70. ^ ^{a b c} Witton 2013, p. 36.
71. ^
    PMID 18509539
    .
72. ^ Witton 2013, p. 37.
73. ^ Witton 2013, p. 39.
74. ^ Witton 2013, p. 43.
75. ^ Witton 2013, p. 47.
76. ^ Witton 2013, p. 48.
77. ^ ^{a b c d e} Witton 2013, p. 51.
78. ^ Goldfuss, A (1831). "Beiträge zur Erkentniss verschiedner Reptilien der Vorwelt". Nova Acta Academiae Leopoldinae. 15: 61–128.
79. S2CID 56480710
    .
80. ^ Briggs, Helen (2018-12-17). "Fur flies over new pterosaur fossils". BBC News. Retrieved 2018-12-19.
81. S2CID 222168569
    .
82. PMID 19656798
    .
83. S2CID 4314989
    .
84. S2CID 222163211
    .
85. S2CID 56480834
    .
86. PMID 35444275
    .
87. ^ ^{a b} Witton 2013, p. 5.
88. ^ Wellnhofer 1991, p. 22.
89. ^ Witton 2013, p. 6.
90. ^ Witton 2013, pp. 6–7.
91. ^ ^{a b c d} Witton 2013, p. 7.
92. ^ Collini, C.A. (1784). "Sur quelques Zoolithes du Cabinet d'Histoire naturelle de S. A. S. E. Palatine & de Bavière, à Mannheim." Acta Theodoro-Palatinae Mannheim 5 Pars Physica, pp. 58–103 (1 plate).
93. ^ Wagler, J. (1830). Natürliches System der Amphibien Munich, 1830: 1–354.
94. ^ Cuvier G (1801). "[Reptile volant]. In: Extrait d'un ouvrage sur les espèces de quadrupèdes dont on a trouvé les ossemens dans l'intérieur de la terre". Journal de Physique, de Chimie et d'Histoire Naturelle. 52: 253–67.
95. ^ Cuvier, G., 1809, "Mémoire sur le squelette fossile d'un Reptil volant des environs d'Aichstedt, que quelques naturalistes ont pris pour un oiseau, et donc nous formons un genre de Sauriens, sous le nom de Ptero-Dactyle", Annales du Musée d'Histoire Naturelle, Paris, 13 pp. 424–37
96. ^ Rafinesque, C.S., 1815, Analyse de la Nature ou tableau de l'univers et des corps organisés, Palermo
97. ^ Von Soemmerring, S. T., 1812, "Über einen Ornithocephalus oder über das unbekannten Thier der Vorwelt, dessen Fossiles Gerippe Collini im 5. Bande der Actorum Academiae Theodoro-Palatinae nebst einer Abbildung in natürlicher Grösse im Jahre 1784 beschrieb, und welches Gerippe sich gegenwärtig in der Naturalien-Sammlung der königlichen Akademie der Wissenschaften zu München befindet", Denkschriften der königlichen bayerischen Akademie der Wissenschaften, München: mathematisch-physikalische Classe 3: 89–158
98. ^ Wellnhofer 1991, p. 27.
99. ^ Newman, E (1843). "Note on the Pterodactyle Tribe considered as Marsupial Bats". Zoologist. 1: 129–31.
100. ^ Kaup, J. (1834). "Versuch einer Eintheilung der Säugethiere in 6 Stämme und der Amphibien in 6 Ordnungen". Isis von Oken. 1834: 311–315.
101. ^ Wellnhofer 1991, p. 28.
102. ^ Wellnhofer 1991, p. 29.
103. ^ Wellnhofer 1991, p. 33.
104. ^ Seeley, H.G., 1870, Ornithosauria – an elementary study of the bones of Pterodactyles, Cambridge University Press
105. ^ Seeley, H.G., 1901, Dragons of the Air: An account of extinct flying reptiles, Londen: Methuen
106. S2CID 30819954
     .
107. ^ ^{a b} Wellnhofer 1991, p. 35.
108. ^ ^{a b c} Wellnhofer 1991, p. 36.
109. ^ ^{a b} Wellnhofer 1991, p. 31.
110. ^ Wellnhofer 1991, pp. 37–38.
111. ^ Marsh, O.C. (1882). "The wings of Pterodactyles". American Journal of Science. 3 (16): 223.
112. ^ Zittel, K.A. (1882). "Über Flugsaurier aus dem lithografischen Schiefer Bayerns". Palaeontographica. 29: 47–80.
113. ^ Broili, F., 1927, "Ein Ramphorhynchus mit Spuren von Haarbedeckung", Sitzungsberichte der Bayerischen Akademie der Wissenschaften p. 49-67
114. S2CID 19084773. Archived from the original
     (PDF) on 2020-07-28. Retrieved 2019-10-27.
115. ^ Hankin E.H. & Watson D.S.M.; "On the Flight of Pterodactyls", The Aeronautical Journal, October 1914, pp. 324–35
116. ^ Bakker, Robert, 1986, The Dinosaur Heresies, Londen: Penguin Books, 1988, p. 283
117. ^ Padian, K (1979). "The wings of pterosaurs: A new look". Discovery. 14: 20–29.
118. ^ Padian, K., 1980, Studies of the structure, evolution, and flight of pterosaurs (reptilia: Pterosauria), Ph.D. diss., Department of Biology, Yale University
119. ^
     S2CID 88434056
     .
120. ^ ^{a b c d e} Witton 2013, p. 9.
121. ^ Wellnhofer, P., 1978, Handbuch der Paläoherpetologie XIX. Pterosauria, Urban & Fischer, München
122. ^ Wellnhofer 1991, pp. 1–192.
123. S2CID 32518380
     .
124. ^ ^{a b} Witton 2013
125. ^ ^{a b} Witton 2013, p. 10.
126. ^ "'Superbly preserved' pterosaur fossil unearthed in Scotland". Associated Press (AP). 22 Feb 2022.
127. ^ Witton 2013, p. 13.
128. ^ Witton 2013, pp. 14, 17.
129. PMC 1692658
     .
130. doi:10.1111/j.1096-3642.1996.tb01267.x
     .
131. S2CID 6050601
     .
132. ^
     S2CID 86145645
     .
133. S2CID 83493714
     .
134. PMID 27162705
     .
135. PMID 32117608
     .
136. ^
     S2CID 228077525
     .
137. ^ "Paleontologists find pterosaur precursors that fill a gap in early evolutionary history". phys.org. Retrieved 2020-12-14.
138. ^ Black, Riley. "Pterosaur Origins Flap into Focus". Scientific American. Retrieved 2020-12-14.
139. doi:10.1016/j.earscirev.2021.103777
     .
140. ^ Witton 2013, p. 18.
141. ^ Rupert Wild, 1983, "Über die Ursprung der Flugsaurier", Weltenberger Akademie, Erwin Rutte-Festschrift, pp. 231–38
142. ^
     PMID 26157605
     .
143. ^ BBC Documentary: Walking with dinosaurs (episode 4 ) – Giant Of The Skies at 22', Tim Haines, 1999
144. PMID 16533822
     .
145. S2CID 84324007
     .
146. ^
     PMID 29534059
     .
147. S2CID 84617119
     .
148. S2CID 56002643. Archived from the original
     (PDF) on 2013-01-15. Retrieved 2012-12-29.
149. S2CID 85673254
     .
150. PMID 27853614
     .
151. ^ Haluza, A.; Apesteguía, S. (2007). "Pterosaur remains (Archosauria, Ornithodira) from the early Late Cretaceous of "La Buitrera", Río Negro, Argentina". XXIII Jornadas Argentinas de Paleontología de Vertebrados.
152. ^
     S2CID 239257717
     .
153. S2CID 128892642
     .
154. ISBN 1862393613
155. ISBN 9780429821202
     .
156. ISBN 0122268105
     .
157. S2CID 13458087
     .
158. ^ ^{a b} Alleyne, Richard (1 October 2008). "Pterodactyls were too heavy to fly, scientist claims". The Telegraph. Archived from the original on 31 October 2009. Retrieved 2 March 2012.
159. ^ Powell, Devin (2 October 2008). "Were pterosaurs too big to fly?". NewScientist. Retrieved 2 March 2012.
160. ISBN 978-0-8137-2376-1
     .
161. ^ Naish, Darren (February 18, 2009). "Pterosaurs breathed in bird-like fashion and had inflatable air sacs in their wings". ScienceBlogs. Archived from the original on February 21, 2009. Retrieved 3 April 2016.
162. ^ ^{a b c} "Why pterosaurs weren't so scary after all". The Observer newspaper. 11 August 2013. Retrieved 12 August 2013.
163. ^ ^{a b} Hecht, Jeff (16 November 2010). "Did giant pterosaurs vault aloft like vampire bats?". NewScientist. Retrieved 2 March 2012.
164. ^ MacCready, P. (1985). "The Great Pterodactyl Project" (PDF). Engineering & Science. 49 (2): 18–24.
165. ^ Molotsky, Irvin (28 January 1986). "With Wings Flapping, Model Pterodactyl Takes to Air". New York Times.
166. ^ "The wingtips of the pterosaurs: Anatomy, aeronautical function and 3 ecological implications" (PDF). Qmro.qmul.ac.uk. Retrieved 25 June 2022.
167. S2CID 27659270
     .
168. doi:10.1146/annurev.es.08.110177.002241
     .
169. ^ Anthes, Emily (November 18, 2013). "Coldblooded Does Not Mean Stupid". The New York Times.
170. PMID 27635315
     .
171. S2CID 129113446
     .
172. S2CID 54996027
     .
173. doi:10.1111/j.1502-3931.1996.tb01673.x
     .
174. ^ ^{a b c} Witton 2013, p. 51
175. S2CID 130685990
     .
176. ^ Witton 2013, p. 103.
177. ^ Witton 2013, p. 121.
178. ^ Witton 2013, p. 122.
179. S2CID 53688256
     .
180. ^ Witton 2013, p. 134.
181. S2CID 128545851
     .
182. S2CID 225130037
     .
183. ^ Witton 2013, pp. 150–51.
184. ^ Witton 2013, p. 199.
185. PMID 28950013
     .
186. ^ Pêgas, R. V., & Kellner, A. W. (2015). Preliminary mandibular myological reconstruction of Thalassodromeus sethi (Pterodactyloidea: Tapejaridae). Flugsaurier 2015 Portsmouth, abstracts, 47–48
187. doi:10.4202/app.00005.2013
     .
188. PMID 28133577
     .
189. ^ Witton, M.; Brusatte, S.; Dyke, G.; Naish, D.; Norell, M.; Vremir, M. (2013). Pterosaur overlords of Transylvania: short-necked giant azhdarchids in Late Cretaceous Romania. The Annual Symposium of Vertebrate Paleontology and Comparative Anatomy. Edinburgh. Archived from the original on 2016-04-06.
190. doi:10.1016/j.cretres.2014.11.001
     .
191. ^
     doi:10.1093/zoolinnean/zlaa163
     .
192. S2CID 4398855
     .
193. S2CID 4416203
     .
194. S2CID 206529739
     .
195. ^
     PMID 24909325.^{[permanent dead link}
     ]
196. S2CID 85055204
     .
197. PMID 26153915
     .
198. S2CID 4428545
     .
199. ^ ^{a b} "Pterosaur hatchlings needed their parents, trove of eggs reveals (Update)". phys.org. Retrieved 2020-03-21.
200. ^
     S2CID 88244184
     .
201. ^
     PMID 22355361
     .
202. ^ "First 3D pterosaur eggs found with their parents". phys.org. Retrieved 2020-03-21.
203. PMID 31185866
     .
204. PMID 34294737
     .
205. PMID 37464754
     .
206. ^ Bristol, University of. "July: Pterosaurs parents | News and features | University of Bristol". www.bristol.ac.uk. Retrieved 2023-08-22.
207. S2CID 33253407
     .
208. ^ ^{a b c} Hone, D. (2010). "Pterosaurs In Popular Culture." Pterosaur.net, Accessed 27 August 2010.
209. ISBN 1-86239-143-2
     .
210. ^ Berry 2005, p. 452.
211. ^ ^{a b} Thomas, H.N. (2020). "The One Born of Fire: a pterosaurological analysis of Rodan". Journal of Geek Studies 7: 53–59.
212. ^ Gonzales, Dave (October 12, 2016). "A Monster-Sized Breakdown of Every Insane 'Godzilla' Movie". Thrillist. Retrieved July 11, 2019.
213. ^ Sharf, Zack (December 10, 2018). "'Godzilla: King of the Monsters' Trailer Turns Mothra, Rodan, and More Into Epic Spectacle" (video). IndieWire. Retrieved July 11, 2019.
214. ^ Mansour, David (2005). From Abba to Zoom A Pop Culture Encyclopedia of the Late 20th Century. Andrews MacMeel Publishing. p. 272.
215. PMID 33848460
     .

Sources

• Berry, Mark F. (2005). The Dinosaur Filmography. McFarland & Company.
  ISBN 978-0-7864-2453-5
  .
• Wellnhofer, Peter (1991). The Illustrated Encyclopedia of Pterosaurs: An Illustrated Natural History of the Flying Reptiles of the Mesozoic Era. Crescent Books.
  ISBN 978-0-517-03701-0
  .
• Witton, Mark (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press.
  ISBN 978-0-691-15061-1
  .

External links

Wikimedia Commons has media related to Pterosauria.

Wikisource has several original texts related to Pterosaurs.

• Pterosaur.net, multi-authored website about all aspects of pterosaur science
• The Pterosaur Database, by Paul Pursglove
• "Comments on the phylogeny of the pterodactyloidea", by Alexander W. A. Kellner (technical)

Retrieved from "https://en.wikipedia.org/w/index.php?title=Pterosaur&oldid=1216781437"