Editing Pterosaur (section)

==Paleobiology==
===Flight===
[[File:Pterosaur respiratory system.jpg|thumb|left|upright|Diagrams showing breathing motion (top two) and internal air sac system (bottom two)]]
The mechanics of pterosaur flight are not completely understood or modeled at this time.<ref name=Sato>{{cite news|last=Alleyne|first=Richard|title=Pterodactyls were too heavy to fly, scientist claims|url=https://www.telegraph.co.uk/science/science-news/3352699/Pterodactyls-were-too-heavy-to-fly-scientist-claims.html|archive-url=https://web.archive.org/web/20091031071320/http://www.telegraph.co.uk/science/science-news/3352699/Pterodactyls-were-too-heavy-to-fly-scientist-claims.html|url-status=dead|archive-date=31 October 2009|access-date=2 March 2012|newspaper=The Telegraph|date=1 October 2008}}</ref><ref>{{cite news|last=Powell|first=Devin|title=Were pterosaurs too big to fly?|url=https://www.newscientist.com/article/mg20026763.800-albatross-study-suggests-pterosaurs-were-too-big-to-fly.html|access-date=2 March 2012|newspaper=NewScientist|date=2 October 2008}}</ref>{{update inline|date=July 2022}}

Katsufumi Sato, a Japanese scientist, did calculations using modern birds and concluded that it was impossible for a pterosaur to stay aloft.<ref name=Sato /> 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.<ref>{{cite book |author1=Templin, R. J. |author2=Chatterjee, Sankar |title=Posture, locomotion, and paleoecology of pterosaurs |publisher=Geological Society of America |location=Boulder, Colo |year=2004 |page=60 |isbn=978-0-8137-2376-1 |url=https://books.google.com/books?id=idta6AVV-tIC&pg=PA60}}</ref> 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both Sato and the authors of ''Posture, Locomotion, and Paleoecology of Pterosaurs'' based their research on the now-outdated theories of pterosaurs being seabird-like, and the size limit does not apply to terrestrial pterosaurs, such as [[Azhdarchidae|azhdarchid]]s and [[Tapejaridae|tapejarid]]s. Furthermore, [[Darren Naish]] concluded that atmospheric differences between the present and the Mesozoic were not needed for the giant size of pterosaurs.<ref name=Nash>{{cite web|date=February 18, 2009 |author=Naish, Darren |author-link=Darren Naish |title=Pterosaurs breathed in bird-like fashion and had inflatable air sacs in their wings |work=[[ScienceBlogs]] |url=http://scienceblogs.com/tetrapodzoology/2009/02/18/pterosaur-breathing-air-sacs/ |access-date=3 April 2016 |url-status=live |archive-url=https://web.archive.org/web/20090221143325/http://scienceblogs.com/tetrapodzoology/2009/02/pterosaur_breathing_air_sacs.php |archive-date=February 21, 2009}}</ref>
[[File:Quad launch.jpg|thumb|Skeletal reconstruction of a quadrupedally launching ''[[Pteranodon|Pteranodon longiceps]]'']]
Another issue that has been difficult to understand is how they [[Takeoff|took off]]. Earlier suggestions were that pterosaurs were largely cold-blooded gliding animals, deriving warmth from the environment like modern lizards, rather than burning calories. In this case, it was unclear how the larger ones of enormous size, with an inefficient cold-blooded metabolism, could manage a bird-like takeoff strategy, using only the hind limbs to generate thrust for getting airborne. Later research shows them instead as being warm-blooded and having powerful flight muscles, and using the flight muscles for walking as quadrupeds.<ref name=wittongrauniad>{{cite news | url=https://www.theguardian.com/science/2013/aug/11/pterosaurs-fossils-research-mark-witton | title=Why pterosaurs weren't so scary after all | work=The Observer newspaper | date=11 August 2013 | access-date=12 August 2013}}</ref> [[Mark Witton]] of the [[University of Portsmouth]] and Mike Habib of [[Johns Hopkins University]] suggested that pterosaurs used a vaulting mechanism to obtain flight.<ref name=wittonhabibnews>{{cite news|last=Hecht|first=Jeff|title=Did giant pterosaurs vault aloft like vampire bats?|url=https://www.newscientist.com/article/dn19724-did-giant-pterosaurs-vault-aloft-like-vampire-bats.html|access-date=2 March 2012|newspaper=NewScientist|date=16 November 2010}}</ref> The tremendous power of their winged forelimbs would enable them to take off with ease.<ref name=wittongrauniad/> Once aloft, pterosaurs could reach speeds of up to {{convert|120|km/h|mph|round=5|abbr=on}} and travel thousands of kilometres.<ref name=wittonhabibnews/>

In 1985, the Smithsonian Institution commissioned aeronautical engineer [[Paul MacCready]] to build a half-scale working model of ''[[Quetzalcoatlus northropi]]''. The replica was launched with a ground-based winch. It flew several times in 1986 and was filmed as part of the Smithsonian's IMAX film ''[[On the Wing (1986 film)|On the Wing]]''.<ref name=maccready1985>{{cite journal| last= MacCready| first= P.| year= 1985| url= http://calteches.library.caltech.edu/596/02/MacCready.pdf| title= The Great Pterodactyl Project| journal= Engineering & Science | volume= 49| number= 2| pages= 18–24}}</ref><ref>{{Cite news|url=https://www.nytimes.com/1986/01/28/science/with-wings-flapping-model-pterodactyl-takes-to-air.html|title=With Wings Flapping, Model Pterodactyl Takes to Air|date=28 January 1986|newspaper=New York Times|first=Irvin|last=Molotsky}}</ref>

Large-headed species are thought to have [[Forward-swept wing|forwardly swept their wings]] in order to better balance.<ref>{{cite web|url=https://qmro.qmul.ac.uk/xmlui/bitstream/handle/123456789/10947/Hone%20The%20wingtips%20of%20the%20pterosaurs%202015%20Accepted.pdf?sequence=1&isAllowed=y|title=The wingtips of the pterosaurs: Anatomy, aeronautical function and 3 ecological implications|website=Qmro.qmul.ac.uk|access-date=25 June 2022}}</ref>

===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 [[wikt:subcutaneous|subcutaneous]] air sac system in at least some pterodactyloids would have further reduced the density of the living animal.<ref name=claessensetal2009/> Like modern crocodilians, pterosaurs appeared to have had a [[Reptile#Respiratory system|hepatic piston]], seeing as their shoulder-pectoral girdles were too inflexible to move the sternum as in birds, and they possessed strong [[gastralia]].<ref>{{cite journal | last1 = Geist | first1 = N. | last2 = Hillenius | first2 = W. | last3 = Frey | first3 = E. | last4 = Jones | first4 = T. | last5 = Elgin | first5 = R. | year = 2014 | title = Breathing in a box: Constraints on lung ventilation in giant pterosaurs | journal = The Anatomical Record | volume = 297 | issue = 12| pages = 2233–53 | doi = 10.1002/ar.22839 | pmid = 24357452| s2cid = 27659270 | doi-access = free }}</ref> Thus, their respiratory system had characteristics comparable to both modern archosaur clades.

===Nervous system===
[[File:Allkaruen_endocast.png|thumb|Brain [[endocast]] of ''[[Allkaruen]]'']]
An X-ray study of pterosaur [[brain]] cavities revealed that the animals (''Rhamphorhynchus muensteri'' and ''[[Anhanguera (pterosaur)|Anhanguera]] santanae'') had massive flocculi. The [[flocculus (cerebellar)|flocculus]] is a brain region that integrates signals from joints, muscles, skin and balance organs.<ref name=Witmer_et_al_2003/> The pterosaurs' flocculi occupied 7.5% of the animals' total brain mass, more than in any other vertebrate. Birds have unusually large flocculi compared with other animals, but these only occupy between 1 and 2% of total brain mass.<ref name=Witmer_et_al_2003/>

The flocculus sends out neural signals that produce small, automatic movements in the eye muscles. These keep the image on an animal's retina steady. Pterosaurs may have had such a large flocculus because of their large wing size, which would mean that there was a great deal more sensory information to process.<ref name=Witmer_et_al_2003/> The low relative mass of the flocculi in birds is also a result of birds having a much larger brain overall; though this has been considered an indication that pterosaurs lived in a structurally simpler environment or had less complex behaviour compared to birds,<ref>{{cite journal | author = Hopson J.A. | year = 1977 | title = Relative Brain Size and Behavior in Archosaurian Reptiles | journal = Annual Review of Ecology and Systematics | volume = 8 | issue = 1 | pages = 429–48 | doi = 10.1146/annurev.es.08.110177.002241| bibcode = 1977AnRES...8..429H }}</ref> recent studies of crocodilians and other reptiles show that it is common for [[sauropsids]] to achieve high intelligence levels with small brains.<ref>{{Cite news|url=https://www.nytimes.com/2013/11/19/science/coldblooded-does-not-mean-stupid.html|title=Coldblooded Does Not Mean Stupid|first=Emily|last=Anthes|newspaper=The New York Times|date=November 18, 2013}}</ref> Studies on the endocast of ''[[Allkaruen]]'' show that brain evolution in [[pterodactyloids]] was a modular process.<ref>{{cite journal | last1 = Codorniú | first1 = Laura | last2 = Paulina Carabajal | first2 = Ariana | last3 = Pol | first3 = Diego | last4 = Unwin | first4 = David | last5 = Rauhut | first5 = Oliver W.M. | year = 2016 | title = A Jurassic pterosaur from Patagonia and the origin of the pterodactyloid neurocranium | journal = PeerJ | volume = 4 | page = e2311 | doi = 10.7717/peerj.2311 | pmid=27635315 | pmc=5012331 | doi-access = free }}</ref>

===Terrestrial locomotion===
[[File:Hatzegopteryx.png|thumb|left|The [[fossil]] trackways show that pterosaurs like ''[[Hatzegopteryx]]'' were quadrupeds, and some rather efficient terrestrial predators.]]
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 [[quadruped]]s or as [[biped]]s. In the 1980s, paleontologist [[Kevin Padian]] suggested that smaller pterosaurs with longer hindlimbs, such as ''[[Dimorphodon]]'', might have walked or even run bipedally, in addition to flying, like [[Geococcyx|road runners]].<ref name="Padian1983">{{cite journal |author=Padian K |title=A Functional Analysis of Flying and Walking in Pterosaurs|jstor=2400656 |journal=Paleobiology |volume=9 |issue=3 |pages=218–39 |year=1983|doi=10.1017/S009483730000765X|bibcode=1983Pbio....9..218P |s2cid=88434056 }}</ref> However, a large number of pterosaur [[fossil trackway|trackways]] were later found with a distinctive four-toed hind foot and three-toed front foot; these are the unmistakable prints of pterosaurs walking on all fours.<ref>{{cite journal |author=Padian K |title=Pterosaur Stance and Gait and the Interpretation of Trackways |journal=Ichnos |volume=10 |issue=2–4 |pages=115–26 |year=2003 |doi=10.1080/10420940390255501|bibcode=2003Ichno..10..115P |s2cid=129113446 |url=http://doc.rero.ch/record/15320/files/PAL_E2625.pdf }}</ref><ref>{{cite journal |vauthors=Hwang K, Huh M, Lockley MG, Unwin DM, Wright JL |title=New pterosaur tracks (Pteraichnidae) from the Late Cretaceous Uhangri Formation, southwestern Korea |journal=Geological Magazine |volume=139 |issue=4 |pages=421–35 |year=2002 |doi=10.1017/S0016756802006647|bibcode=2002GeoM..139..421H |s2cid=54996027 |url=http://edoc.hu-berlin.de/18452/28485 }}</ref>
[[File:Haenamichnuswittonnaish2008.png|upright|thumb|The probable [[Azhdarchidae|azhdarchid]] trace [[fossil]] ''[[Haenamichnus|Haenamichnus uhangriensis]]''.]]
Fossil footprints show that pterosaurs stood with the entire foot in contact with the ground ([[plantigrade]]), in a manner similar to many mammals like [[human]]s and [[bear]]s. Footprints from [[Azhdarchidae|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.<ref name="witton&naish2008">{{cite journal |vauthors=Witton MP, Naish D |title=A reappraisal of azhdarchid pterosaur functional morphology and paleoecology |journal=PLOS ONE |volume=3 |issue=5 |pages=e2271 |year=2008|pmc=2386974 |doi=10.1371/journal.pone.0002271 |pmid=18509539 |editor1-last=McClain |editor1-first=Craig R. |bibcode=2008PLoSO...3.2271W|doi-access=free }}</ref><ref name=wittongrauniad/> Indeed, erect-limbs may be omnipresent in pterosaurs.<ref name="ReferenceA">{{cite journal|doi=10.7717/peerj.1018|pmid=26157605|pmc=4476129|title=Were early pterosaurs inept terrestrial locomotors?|journal=PeerJ|volume=3|pages=e1018|year=2015|last1=Witton|first1=Mark P. |doi-access=free }}</ref>

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.<ref name=unwin1997>{{cite journal |author=Unwin DM |title=Pterosaur tracks and the terrestrial ability of pterosaurs |journal=Lethaia |volume=29 |pages=373–86 |year=1997 |doi=10.1111/j.1502-3931.1996.tb01673.x |issue=4|url=http://doc.rero.ch/record/16203/files/PAL_E3429.pdf }}</ref> Early pterosaurs have long been considered particularly cumbersome locomotors due to the presence of large [[Uropatagium|cruropatagia]], but they too appear to have been generally efficient on the ground.<ref name="ReferenceA"/>
[[File:Lot Plage aux ptérosaures 7 traces Dimitri.jpg|thumb|left|Fossil pterosaur footprints, [[Pterosaur Beach]] (France).]]
The forelimb bones of [[Azhdarchidae|azhdarchids]] and [[Ornithocheiridae|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.<ref name="witton&naish2008"/>

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 [[Ctenochasmatoidea|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.<ref name="witton&naish2008"/> Though clearly forelimb-based launchers, basal pterosaurs have hindlimbs well adapted for hopping, suggesting a connection with archosaurs such as ''[[Scleromochlus]]''.<ref name="ReferenceA"/>

===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.<ref name= "witton2013">{{harvnb|Witton|2013|p=51}}</ref> Pteranodontians conversely have several speciations in their humeri interpreted to have been suggestive of a water-based version of the typical quadrupedal launch, and several like [[boreopterid]]s must have foraged while swimming, as they seem incapable of [[frigatebird]]-like aerial hawking.<ref name="witton2013"/> These adaptations are also seen in terrestrial pterosaurs like [[azhdarchid]]s, which presumably still needed to launch from water in case they found themselves in it. The [[nyctosaurid]] ''[[Alcione (pterosaur)|Alcione]]'' may display adaptations for wing-propelled diving like modern [[gannet]]s and [[tropicbird]]s.<ref name="longrichetal2018" />

===Diet and feeding habits===
[[File:Dimorphodon.png|thumb|Modern interpretations of the diet of ''[[Dimorphodon]]'' have challenged traditional ideas of all pterosaurs being piscivorous]]
Traditionally, almost all pterosaurs were seen as surface-feeding piscivores or fish-eaters, a view that still dominates popular science. Today, many pterosaurs groups are thought to have been terrestrial carnivores, omnivores or insectivores.

Early-on it was recognised that the small [[Anurognathidae]] were nocturnal, aerial insectivores. With highly flexible joints on the wing finger, a broad, triangular wing shape, large eyes and short tail, these pterosaurs were likely analogous to [[nightjars]] or extant insectivorous bats, being capable of high manoeuvrability at relatively low speeds.<ref>{{cite journal | last1 = Bennett | first1 = S. C. | year = 2007 | title = A second specimen of the pterosaur ''Anurognathus ammoni'' | doi = 10.1007/bf02990250 | journal = Paläontologische Zeitschrift | volume = 81 | issue = 4| pages = 376–98| bibcode = 2007PalZ...81..376B | s2cid = 130685990 }}</ref>
[[File:Lusognathus.png|thumb|left|[[Ctenochasmatoid]] pterosaurs such as ''[[Lusognathus]]'' may have had specialised niches in freshwater ecosystems]]
Interpretations of the habits of basal groups have changed profoundly.  ''[[Dimorphodon]]'', envisioned as a [[puffin]] analogue in the past, is indicated by its jaw structure, gait, and poor flight capabilities, as a terrestrial/semiarboreal predator of small mammals, [[squamates]], and large insects.{{sfn|Witton|2013|p=103}} Its robust dentition caused ''[[Campylognathoides]]'' to be seen as a generalist or a terrestrial predator of small vertebrates, but the highly robust humerus and high-aspect wing morphology, suggest it may have been capable of grabbing prey on the wing;{{sfn|Witton|2013|p=121}} a later study indicates it was [[teuthophagous]] based on squid findings within its gut.<ref>Cooper, S. L. A.; Smith, R. E.; Martill, D. M. (2024). "Dietary tendencies of the Early Jurassic pterosaurs Campylognathoides Strand, 1928, and Dorygnathus Wagner, 1860, with additional evidence for teuthophagy in Pterosauria". Journal of Vertebrate Paleontology. e2403577. doi:10.1080/02724634.2024.2403577.</ref> The small insectivorous ''[[Carniadactylus]]'' and the larger ''[[Eudimorphodon]]'' were highly aerial animals and fast, agile flyers with long robust wings. ''Eudimorphodon'' has been found with fish remains in its stomach, but its dentition suggests an opportunistic diet. Slender-winged ''[[Austriadactylus]]'' and ''[[Caviramus]]'' were likely terrestrial/semiarboreal generalists. ''Caviramus'' likely had a strong bite force, indicating an adaptation towards hard food items that might have been chewed in view of the tooth wear.{{sfn|Witton|2013|p=122}}
[[File:Haliskia_Life_Restoration.png|thumb|Many [[pteranodontoid]] pterosaurs such as ''[[Haliskia]]'' likely fed on fish at sea]]
Some [[Rhamphorhynchidae]], such as ''[[Rhamphorhynchus]]'' itself or ''[[Dorygnathus]]'', were fish-eaters with long, slender wings, needle-like dentition and long, thin jaws. ''[[Sericipterus]]'', ''[[Scaphognathus]]'' and ''[[Harpactognathus]]'' had more robust jaws and teeth (which were ziphodont, dagger-shaped, in '' Sericipterus''), and shorter, broader wings. These were either terrestrial/aerial predators of vertebrates<ref name=ACX10>{{cite journal |last1=Andres |first1=B. | last2=Clark |first2=J. M. | last3=Xing | first3=X. |year=2010 |title=A new rhamphorhynchid pterosaur from the Upper Jurassic of Xinjiang, China, and the phylogenetic relationships of basal pterosaurs |journal=Journal of Vertebrate Paleontology |volume=30 |issue=1 |pages=163–87 |doi=10.1080/02724630903409220|bibcode=2010JVPal..30..163A |s2cid=53688256 |url=http://doc.rero.ch/record/31614/files/PAL_E956.pdf }}</ref> or [[corvid]]-like generalists.{{sfn|Witton|2013|p=134}} [[Wukongopteridae]] like ''[[Darwinopterus]]'' were first considered aerial predators. Lacking a robust jaw structure or powerful flying muscles, they are now seen as arboreal or semiterrestrial insectivores. ''Darwinopterus robustidens'', in particular, seems to have been a beetle specialist.<ref name=robustidens>{{cite journal |author1=Lü J. |author2=Xu L. |author3=Chang H. |author4=Zhang X. | year = 2011 | title = A new darwinopterid pterosaur from the Middle Jurassic of western Liaoning, northeastern China and its ecological implications | journal = Acta Geologica Sinica - English Edition | volume = 85 | issue = 3| pages = 507–14 | doi = 10.1111/j.1755-6724.2011.00444.x|bibcode=2011AcGlS..85..507L |s2cid=128545851 }}</ref>

Among pterodactyloids, a greater variation in diet is present. [[Pteranodontia]] contained many piscivorous taxa, such as the [[Ornithocheirae]], [[Boreopteridae]], [[Pteranodontidae]] and Nyctosauridae. [[Niche partitioning]] caused ornithocheirans and the later nyctosaurids to be aerial dip-feeders like today's [[frigatebird]]s (with the exception of the plunge-diving adapted ''[[Alcione elainus]]''), while boreopterids were freshwater diving animals similar to [[cormorants]], and pteranodonts pelagic plunge-divers akin to [[boobies]] and [[gannets]]. An analysis of ''[[Lonchodraco]]'' found clusters of [[Foramen|foramina]] at the tip of its beak; birds with similarly numerous foramina have sensitive beaks used to feel for food, so ''Lonchodraco'' may have used its beak to feel for fish or invertebrates in shallow water.<ref>{{Cite journal |last1=Martill |first1=David M. |last2=Smith |first2=Roy E. |last3=Longrich |first3=Nicholas |last4=Brown |first4=James |date=2021-01-01 |title=Evidence for tactile foraging in pterosaurs: a sensitive tip to the beak of Lonchodraco giganteus (Pterosauria, Lonchodectidae) from the Upper Cretaceous of southern England |url=https://www.sciencedirect.com/science/article/pii/S0195667120303232 |journal=Cretaceous Research |language=en |volume=117 |pages=104637 |doi=10.1016/j.cretres.2020.104637 |bibcode=2021CrRes.11704637M |s2cid=225130037 |issn=0195-6671}}</ref> The [[Istiodactylidae|istiodactylids]] were likely primarily scavengers.{{sfn|Witton|2013|pp=150–51}} [[Archaeopterodactyloidea]] obtained food in coastal or freshwater habitats. ''[[Germanodactylus]]'' and ''[[Pterodactylus]]'' were piscivores, while the [[Ctenochasmatidae]] were suspension feeders, using their numerous fine teeth to filter small organisms from shallow water. ''[[Pterodaustro]]'' was adapted for [[flamingo]]-like filter-feeding.{{sfn|Witton|2013|p=199}}
[[File:Kariridraco_by_Júlia_d’Oliveira.jpg|thumb|left|[[Azhdarchoid]] pterosaurs such as ''[[Kariridraco]]'' fed on terrestrial prey]]
In contrast, [[Azhdarchoidea]] mostly were terrestrial pterosaurs. [[Tapejaridae]] were arboreal omnivores, supplementing seeds and fruits with small insects and vertebrates.<ref name="witton2013"/><ref>{{cite journal | last1 = Wu | first1 = Wen-Hao | last2 = Zhou | first2 = Chang-Fu | last3 = Andres | first3 = Brian | year = 2017 | title = The toothless pterosaur ''Jidapterus edentus'' (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its paleoecological implications | journal = PLOS ONE | volume = 12 | issue = 9| page = e0185486 | doi = 10.1371/journal.pone.0185486 | pmid = 28950013 | pmc = 5614613 | bibcode = 2017PLoSO..1285486W | doi-access = free }}</ref> [[Dsungaripteridae]] were specialist molluscivores, using their powerful jaws to crush the shells of molluscs and crustaceans. [[Thalassodromidae]] were likely terrestrial carnivores. ''[[Thalassodromeus]]'' itself was named after a fishing method known as "skim-feeding", later understood to be biomechanically impossible. Perhaps it pursued relatively large prey, in view of its reinforced jaw joints and relatively high bite force.<ref>Pêgas, R. V., & Kellner, A. W. (2015). Preliminary mandibular myological reconstruction of ''Thalassodromeus sethi'' (Pterodactyloidea: Tapejaridae). Flugsaurier 2015 Portsmouth, abstracts, 47–48</ref> [[Azhdarchidae]] are now understood to be terrestrial predators akin to ground [[hornbills]] or some [[storks]], eating any prey item they could swallow whole.<ref name="wittonnaish2015">{{cite journal | first1 = M.P. | last1 = Witton | first2 = D. | last2 = Naish | title = Azhdarchid pterosaurs: water-trawling pelican mimics or "terrestrial stalkers"? | journal = Acta Palaeontologica Polonica | date = 2015 | volume = 60 | issue = 3 | doi = 10.4202/app.00005.2013| doi-access = free }}</ref> ''[[Hatzegopteryx]]'' was a robustly built predator of relatively large prey, including medium-sized dinosaurs.<ref name="witton2017">{{cite journal | first2 = M.P. | last2 = Witton | first1 = D. | last1 = Naish | title = Neck biomechanics indicate that giant Transylvanian azhdarchid pterosaurs were short-necked arch predators | volume = 5 | doi = 10.7717/peerj.2908 | pmid = 28133577 | pmc = 5248582 | journal = PeerJ | date = 2017 | page=e2908 | doi-access = free }}</ref><ref>{{cite conference | last1 = Witton | first1 = M. | last2 = Brusatte | first2 = S. | last3 = Dyke | first3 = G. | last4 = Naish | first4 = D. | last5 = Norell | first5 = M. | last6 = Vremir | first6 = M. | title = Pterosaur overlords of Transylvania: short-necked giant azhdarchids in Late Cretaceous Romania | conference = The Annual Symposium of Vertebrate Paleontology and Comparative Anatomy | date = 2013 | location = Edinburgh | url = http://svpca.org/abstracts/abstract.php?abstID=00000001864&prog=on | url-status = dead | archive-url = https://web.archive.org/web/20160406020702/http://svpca.org/abstracts/abstract.php?abstID=00000001864&prog=on | archive-date = 2016-04-06}}</ref> ''[[Alanqa]]'' may have been a specialist molluscivore.<ref name="martillandibrahim2015">{{cite journal |last1=Martill |first1=David M. |last2=Ibrahim |first2=Nizar |title=An unusual modification of the jaws in cf. Alanqa, a mid-Cretaceous azhdarchid pterosaur from the Kem Kem beds of Morocco |journal=Cretaceous Research |date=March 2015 |volume=53 |pages=59–67 |doi=10.1016/j.cretres.2014.11.001 |bibcode=2015CrRes..53...59M |url=https://researchportal.port.ac.uk/portal/en/publications/an-unusual-modification-of-the-jaws-in-cf-alanqa-a-midcretaceous-azhdarchid-pterosaur-from-the-kem-kem-beds-of-morocco(ce004df9-c86a-4cf9-9fb8-1172211774cc).html }}</ref>

A 2021 study reconstructed the adductor musculature of skulls from [[Pterodactyloidea|pterodactyloids]], estimating the bite force and potential dietary habits of nine selected species.<ref name="pegas">{{cite journal |last1=Pêgas |first1=Rodrigo V |last2=Costa |first2=Fabiana R |last3=Kellner |first3=Alexander W A |title=Reconstruction of the adductor chamber and predicted bite force in pterodactyloids (Pterosauria) |journal=Zoological Journal of the Linnean Society |date=24 September 2021 |volume=193 |issue=2 |pages=602–635 |doi=10.1093/zoolinnean/zlaa163 }}</ref> The study corroborated the view of [[pteranodontids]], [[nyctosaurids]] and [[Anhanguera (pterosaur)|anhanuerids]] as [[piscivores]] based on them being relatively weak but fast biters, and suggest that ''[[Tropeognathus mesembrinus]]'' was specialised in consuming relatively large prey compared to ''[[Anhanguera (pterosaur)|Anhanguera]]''. ''[[Dsungaripterus]]'' was corroborated as a [[durophagy|durophage]], with ''[[Thalassodromeus]]'' proposed to share this feeding habit based on high estimated [[bite force quotient]]s (BFQ) and absolute bite force values.<ref name="pegas"/> ''[[Tapejara wellnhoferi]]'' was corroborated as a specialised consumer of hard plant material with a relatively high BFQ and high mechanical advantage, and ''[[Caupedactylus ybaka]]'' and ''[[Tupuxuara leonardii]]'' were proposed to be ground-feeding generalists with intermediate bite force values and less specialised jaws.<ref name="pegas"/>

===Natural predators===
[[File:20130825_Brazil_Rio_de_Janeiro_0144.jpg|thumb|left|[[Theropod]] dinosaur ''[[Irritator]]'' shown feeding on a pterosaur]]
Pterosaurs are known to have been eaten by [[theropoda|theropods]]. In the 1 July 2004 edition of ''[[Nature (journal)|Nature]]'', paleontologist [[Éric Buffetaut]] discusses an Early Cretaceous fossil of three cervical [[vertebra]]e of a pterosaur with the broken tooth of a [[spinosaur]], most likely ''[[Irritator]]'', embedded in it. The vertebrae are known not to have been eaten and exposed to digestion, as the joints are still articulated.<ref>{{cite journal |vauthors=Buffetaut E, Martill D, Escuillié F |title=Pterosaurs as part of a spinosaur diet |journal=Nature |volume=430 |issue=6995 |page=33 |date=July 2004 |pmid=15229562 |doi=10.1038/430033a |bibcode=2004Natur.429...33B|s2cid=4398855 |doi-access=free }}</ref> Fossils of ''Pteranodon'' have been found with tooth marks from sharks such as ''[[Squalicorax]]'',<ref>{{Cite web|url=https://www.nationalgeographic.com/science/2018/10/news-sharks-eating-pterosaurs-fossils-cretaceous-paleontology/|archive-url=https://web.archive.org/web/20181003163916/https://www.nationalgeographic.com/science/2018/10/news-sharks-eating-pterosaurs-fossils-cretaceous-paleontology/|url-status=dead|archive-date=October 3, 2018|title=Prehistoric sharks feasted on flying reptiles, fossil reveals|date=October 3, 2018|website=Science & Innovation}}</ref> and a fossil with tooth marks from the ''[[Toolebuc formation]]'' has been interpreted as being attacked or scavenged by an [[ichthyosaur]] (most likely ''[[Platypterygius]]'').

===Reproduction and life history===
[[File:Pterodactylus micronyx - IMG 0677.jpg|thumb|Fossil [[Pterodactyloidea|pterodactyloid]] juvenile from the Solnhofen Limestone]]
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 eggs were found in the quarries of Liaoning, the same place that yielded feathered dinosaurs, and in Loma del Pterodaustro ([[Lagarcito Formation]], [[Argentina]]). The eggs from [[Liaoning]] were squashed flat with no signs of cracking, so evidently the eggs had leathery shells, as in modern lizards.<ref name="Ji_et_al_2004">{{cite journal |vauthors=Ji Q, Ji SA, Cheng YN, etal |title=Palaeontology: pterosaur egg with a leathery shell |journal=Nature |volume=432 |issue=7017 |page=572 |date=December 2004|doi=10.1038/432572a |pmid=15577900|bibcode=2004Natur.432..572J |s2cid=4416203 |url=http://doc.rero.ch/record/14929/files/PAL_E2072.pdf }}</ref> The egg from the [[Lagarcito Formation]] was laid by a ''[[Pterodaustro]]'',<ref name="Codorniú et al. 2004">{{cite journal |last1=Codorniú |first1=L. |last2=Chiappe |first2=L. |last3=Rivarola |first3=D. |title=Primer reporte de un embrión de pterosaurio (Cretácico inferior, San Luis, Argentina) |journal=Ameghiniana |date=2014 |volume=41 |issue=4 (supplement; abstracts from XX Jornadas Argentinas de Paleontología de Vertebrados, La Plata, 26–28 May 2004) |page=40R |url=https://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/2705 }}</ref><ref name="Chiappe et al. 2004">{{cite journal |last1=Chiappe |first1=Luis M. |last2=Codorniú |first2=Laura |last3=Grellet-Tinner |first3=Gerald |last4=Rivarola |first4=David |title=Argentinian unhatched pterosaur fossil |journal=Nature |date=December 2004 |volume=432 |issue=7017 |pages=571–572 |doi=10.1038/432571a |pmid=15577899 |url=https://doi.org/10.1038/432571a |language=en |issn=1476-4687|hdl=11336/156308 |hdl-access=free }}</ref> a pterosaur known by abundant material.<ref name="Codorniú et al. 2013">{{cite journal |last1=Codorniú |first1=Laura |last2=Chiappe |first2=Luis M. |last3=Cid |first3=Fabricio D. |title=First occurrence of stomach stones in pterosaurs |journal=Journal of Vertebrate Paleontology |date=May 2013 |volume=33 |issue=3 |pages=647–654 |doi=10.1080/02724634.2013.731335 |bibcode=2013JVPal..33..647C |url=https://doi.org/10.1080/02724634.2013.731335 |language=en |issn=0272-4634|hdl=11336/4391 |hdl-access=free }}</ref> 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.<ref name=luetal2011>{{cite journal |author1=Lü J. |author2=Unwin D.M. |author3=Deeming D.C. |author4=Jin X. |author5=Liu Y. |author6=Ji Q. | year = 2011 | title = An egg-adult association, gender, and reproduction in pterosaurs | journal = Science | volume = 331 | issue = 6015| pages = 321–24 | doi = 10.1126/science.1197323 | pmid = 21252343|bibcode=2011Sci...331..321L |s2cid=206529739 }}</ref> In 2014 five unflattened eggs from the species ''[[Hamipterus|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.<ref name=":0">{{cite journal|last1=Wang|first1=Xiaolin|title=Sexually Dimorphic Tridimensionally Preserved Pterosaurs and Their Eggs from China|journal=Current Biology|doi=10.1016/j.cub.2014.04.054|pmid=24909325|volume=24|issue=12|pages=1323–30|year=2014|doi-access=free|bibcode=2014CBio...24.1323W }}{{Dead link|date=May 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> A study of pterosaur eggshell structure and chemistry published in 2007 indicated that it is likely pterosaurs buried their eggs, like modern [[crocodile]]s and [[turtle]]s. 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 [[bird]]s.<ref name="grellet-tinneretal2007">{{cite journal |vauthors=Grellet-Tinner G, Wroe S, Thompson MB, Ji Q |title=A note on pterosaur nesting behavior |journal=Historical Biology |volume=19 |issue=4 |pages=273–77 |year=2007 |doi=10.1080/08912960701189800|bibcode=2007HBio...19..273G |s2cid=85055204 }}</ref>

A ''Darwinopterus'' specimen showcases that at least some pterosaurs had a pair of functional [[ovaries]], as opposed to the single functional ovary in birds, dismissing the reduction of functional ovaries as a requirement for powered flight.<ref>{{cite journal | last1 = Xiaolin Wang | first1 = Kellner Alexander W.A. | last2 = Cheng | first2 = Xin | last3 = Jiang | first3 = Shunxing | last4 = Wang | first4 = Qiang | last5 = Sayão Juliana | first5 = M. | last6 = Rordrigues Taissa | first6 = Costa Fabiana R. | last7 = Li | first7 = Ning | last8 = Meng | first8 = Xi | last9 = Zhou | first9 = Zhonghe | year = 2015 | title = Eggshell and Histology Provide Insight on the Life History of a Pterosaur with Two Functional Ovaries | journal = Anais da Academia Brasileira de Ciências | volume = 87 | issue = 3| pages = 1599–1609 | doi = 10.1590/0001-3765201520150364| pmid = 26153915| doi-access = free }}</ref>
[[File:Rhamphorhynchus_Growth.jpg|thumb|left|Growth series of ''[[Rhamphorhynchus]]'' specimens showing changes throughout life]]
Wing membranes preserved in pterosaur embryos are well developed, suggesting that pterosaurs were ready to fly soon after birth.<ref>{{cite journal |vauthors=Wang X, Zhou Z |title=Palaeontology: pterosaur embryo from the Early Cretaceous |journal=Nature |volume=429 |issue=6992 |page=621 |date=June 2004 |pmid=15190343 |doi=10.1038/429621a |bibcode=2004Natur.429..621W|s2cid=4428545 |doi-access=free }}</ref> However, [[tomography]] scans of fossilised ''Hamipterus'' eggs suggests that the young pterosaurs had well-developed thigh bones for walking, but weak chests for flight.<ref name=":1">{{Cite web|url=https://phys.org/news/2017-11-hundreds-pterosaur-eggs-reveal-early.html|title=Pterosaur hatchlings needed their parents, trove of eggs reveals (Update)|website=phys.org|language=en-us|access-date=2020-03-21}}</ref> It is unknown if this holds true for other pterosaurs. Fossils of pterosaurs only a few days to a week old (called "flaplings") have been found, representing several pterosaur families, including pterodactylids, rhamphorhinchids, ctenochasmatids and azhdarchids.<ref name=DU06b/> All preserved bones that show a relatively high degree of hardening (''ossification'') for their age, and wing proportions similar to adults. In fact, many pterosaur flaplings have been considered adults and placed in separate species in the past. Additionally, flaplings are normally found in the same sediments as adults and juveniles of the same species, such as the ''Pterodactylus'' and ''Rhamphorhynchus'' flaplings found in the [[Solnhofen limestone]] of Germany, and ''Pterodaustro'' flaplings from Argentina. All are found in deep aquatic environment far from shore.<ref name=bennett1995>{{cite journal | author = Bennett S. C. | year = 1995 | title = A statistical study of ''Rhamphorhynchus'' from the Solnhofen Limestone of Germany: Year-classes of a single large species | jstor=1306329 | journal = Journal of Paleontology | volume = 69 | issue = 3 | pages = 569–80| doi = 10.1017/S0022336000034946| bibcode = 1995JPal...69..569B | s2cid = 88244184 }}</ref>
[[File:Lamberts_Bay_Bird_Island.jpg|thumb|Some pterosaurs may have reproduced in [[bird colony|colonies]] similar to those of modern seabirds]]
For the majority of pterosaur species, it is not known whether they practiced any form of parental care, but their ability to fly as soon as they emerged from the egg and the numerous flaplings found in environments far from nests and alongside adults has led most researchers, including Christopher Bennett and David Unwin, to conclude that the young were dependent on their parents for a relatively short period of time, during a period of rapid growth while the wings grew long enough to fly, and then left the nest to fend for themselves, possibly within days of hatching.<ref name=DU06b/><ref name=lifehistory/> Alternatively, they may have used stored yolk products for nourishment during their first few days of life, as in modern reptiles, rather than depend on parents for food.<ref name=bennett1995/> Fossilised ''Hamipterus'' nests were shown preserving many male and female pterosaurs together with their eggs in a manner to a similar to that of modern [[seabird]] [[Bird colony|colonies]].<ref name=":0" /><ref>{{Cite web|url=https://phys.org/news/2014-06-3d-pterosaur-eggs-parents.html|title=First 3D pterosaur eggs found with their parents|website=phys.org|language=en-us|access-date=2020-03-21}}</ref> Due to how underdeveloped the chests of the hatchlings were for flying, it was suggested that ''Hamipterus'' may have practiced some form of parental care.<ref name=":1" /> However, this study has since been criticised.<ref>{{Cite journal|doi = 10.1098/rspb.2019.0409|title = Prenatal development in pterosaurs and its implications for their postnatal locomotory ability|year = 2019|last1 = Unwin|first1 = David Michael|last2 = Deeming|first2 = D. Charles|journal = Proceedings of the Royal Society B: Biological Sciences|volume = 286|issue = 1904|pmid = 31185866|pmc = 6571455}}</ref> Most evidence currently leans towards pterosaur hatchlings being [[Precociality|superprecocial]], similar to that of [[megapode]] birds, which fly after hatching without the need of parental care. A further study compares evidence for superprecociality and "late term flight" and overwhelmingly suggests that most if not all pterosaurs were capable of flight soon after hatching.<ref>{{Cite journal|doi = 10.1038/s41598-021-92499-z|title = Powered flight in hatchling pterosaurs: Evidence from wing form and bone strength|year = 2021|last1 = Naish|first1 = Darren|last2 = Witton|first2 = Mark P.|last3 = Martin-Silverstone|first3 = Elizabeth|journal = Scientific Reports|volume = 11|issue = 1|page = 13130|pmid = 34294737|pmc = 8298463|bibcode = 2021NatSR..1113130N}}</ref> A later study suggested that while smaller-bodied pterosaurs were most likely superprecocial or precocial, owing to the consistent or decreasing wing aspect ratio during growth, certain large-bodied pterosaurs, such as ''Pteranodon'' showed possible evidence of their young being [[altricial]], due to the fast rate the limb bones closest to the body grew compared to any other element of their skeleton after hatching. Other factors mentioned were the limits of soft shelled eggs and the size of the pelvic opening of large female pterosaurs.<ref>{{Cite journal |last1=Yang |first1=Zixiao |last2=Jiang |first2=Baoyu |last3=Benton |first3=Michael J. |last4=Xu |first4=Xing |last5=McNamara |first5=Maria E. |last6=Hone |first6=David W. E. |date=2023-07-26 |title=Allometric wing growth links parental care to pterosaur giantism |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=290 |issue=2003 |doi=10.1098/rspb.2023.1102 |issn=0962-8452 |pmc=10354479 |pmid=37464754}}</ref><ref>{{Cite web |last=Bristol |first=University of |title=July: Pterosaurs parents {{!}} News and features {{!}} University of Bristol |url=https://www.bristol.ac.uk/news/2023/july/pterosaurs-parents.html |access-date=2023-08-22 |website=www.bristol.ac.uk |language=en-GB}}</ref>

Growth rates of pterosaurs once they hatched varied across different groups. In earlier, long-tailed pterosaurs ("[[rhamphorhynchoid]]s"), such as ''Rhamphorhynchus'', the average growth rate during the first year of life was 130% to 173%, slightly faster than the growth rate of [[alligator]]s. Growth in these species slowed after sexual maturity, and it would have taken more than three years for ''Rhamphorhynchus'' to attain maximum size.<ref name=lifehistory>{{Cite journal | last1 = Prondvai | first1 = E. | last2 = Stein | first2 = K. | last3 = Ősi | first3 = A. | last4 = Sander | first4 = M. P. | editor1-last = Soares | editor1-first = Daphne | title = Life history of ''Rhamphorhynchus'' inferred from bone histology and the diversity of pterosaurian growth strategies | doi = 10.1371/journal.pone.0031392 | journal = PLOS ONE | volume = 7 | issue = 2 | pages = e31392 | year = 2012 | pmid = 22355361 | pmc = 3280310| bibcode = 2012PLoSO...731392P | doi-access = free }}</ref> In contrast, the later [[pterodactyloid]] pterosaurs, such as ''[[Pteranodon]]'', grew to adult size within the first year of life. Additionally, pterodactyloids had ''determinate growth'', meaning that the animals reached a fixed maximum adult size and stopped growing.<ref name="bennett1995"/>

A 2021 study indicates that pterosaur juveniles of larger species increasingly took the roles previously occupied by adult small pterosaurs.<ref name="Smith et al 2021"/>

===Daily activity patterns===
Comparisons between the [[sclerotic ring|scleral ring]]s of pterosaurs and modern birds and reptiles have been used to infer daily activity patterns of pterosaurs. The pterosaur genera ''[[Pterodactylus]]'', ''[[Scaphognathus]]'', and ''[[Tupuxuara]]'' have been inferred to be [[Diurnality|diurnal]], ''[[Ctenochasma]]'', ''[[Pterodaustro]]'', and ''[[Rhamphorhynchus]]'' have been inferred to be [[nocturnal]], and ''[[Tapejara (pterosaur)|Tapejara]]'' has been inferred to be [[cathemeral]], being active throughout the day for short intervals. As a result, the possibly fish-eating ''Ctenochasma'' and ''Rhamphorhynchus'' may have had similar activity patterns to modern nocturnal seabirds, and the filter-feeding ''Pterodaustro'' may have had similar activity patterns to modern [[Anseriformes|anseriform]] birds that feed at night. The differences between activity patterns of the [[Paleobiota of the Solnhofen Formation|Solnhofen]] pterosaurs ''Ctenochasma'', ''Rhamphorhynchus'', ''Scaphognathus'', and ''Pterodactylus'' may also indicate [[niche partitioning]] between these genera.<ref>{{cite journal|author1=Schmitz, L. |author2=Motani, R. |year=2011 |title=Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology |journal=Science |volume=332 |issue= 6030|pages= 705–08|doi=10.1126/science.1200043 |pmid=21493820 |bibcode=2011Sci...332..705S|s2cid=33253407 }}</ref>