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Azhdarchidae

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Azhdarchids
Temporal range:
Late Cretaceous, 92–66 Ma
Reconstructed skeletons of the azhdarchids Hatzegopteryx (A-B), Arambourgiania (C), and Quetzalcoatlus (D-E)
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: †Pterosauria
Suborder: †Pterodactyloidea
Clade: †Azhdarchoidea
Clade: †Azhdarchiformes
Family: †Azhdarchidae
Nesov, 1984
Type species
†Azhdarcho lancicollis
Nesov, 1984
Genera
Synonyms
  • "Titanopterygiidae"
    Padian, 1984 (preoccupied)

Azhdarchidae (from the Persian word azhdar, اژدر, a dragon-like creature in Persian mythology) is a family of pterosaurs known primarily from the Late Cretaceous. Azhdarchids include some of the largest flying animals discovered, but smaller cat-size members have also been found.[1] Originally considered a sub-family of Pteranodontidae, Nesov (1984)[2] named the Azhdarchinae to include the pterosaurs Azhdarcho, Quetzalcoatlus, and Titanopteryx (now known as Arambourgiania). They were among the last known surviving members of the pterosaurs, and were a rather successful group with a worldwide distribution. Previously it was thought that by the end of the Cretaceous, most pterosaur families except for the Azhdarchidae disappeared from the fossil record,[3] but recent studies indicate a wealth of pterosaurian fauna, including pteranodontids, nyctosaurids, tapejarids and several indeterminate forms.[4]

Description

[edit]
Reconstructed feeding posture of an azhdarchid with sagittally (longitudinally) aligned limbs

Azhdarchids are characterized by their long legs and extremely long necks, made up of elongated neck vertebrae which are round in cross section. Most species of azhdarchids are still known mainly from their distinctive neck bones and not much else. The few azhdarchids that are known from reasonably good skeletons include Zhejiangopterus and Quetzalcoatlus. Azhdarchids are also distinguished by their relatively large heads and long, spear-like jaws. There are two major types of azhdarchid morphologies: the "blunt-beaked" forms with shorter and deeper bills and the "slender-beaked" forms with longer and thinner jaws.[5]

It had been suggested azhdarchids were skimmers,[2][6] but further research has cast doubt on this idea, demonstrating that azhdarchids lacked the necessary adaptations for a skim-feeding lifestyle, and that they may have led a more terrestrial existence similar to modern storks and ground hornbills.[7][8][9][10][11] Most large azhdarchids probably fed on small prey, including hatchling and small dinosaurs; in an unusual modification of the azhdarchid bodyplan, the robust Hatzegopteryx may have tackled larger prey as the apex predator in its ecosystem.[12] In another departure from typical azhdarchid lifestyles, the jaw of Alanqa may possibly be an adaptation to crushing shellfish and other hard foodstuffs.[13]

Azhdarchids are generally medium- to large-sized pterosaurs, with the largest achieving wingspans of 10–12 metres (33–39 ft),[14] but several small-sized species have recently been discovered.[15][16] Another azhdarchid that is currently unnamed, recently discovered in Transylvania, may be the largest representative of the family thus far discovered. This unnamed specimen (nicknamed "Dracula" by paleontologists), currently on display in the Altmühltal Dinosaur Museum in Bavaria is estimated to have a wingspan of 12–20 m (39–66 ft), although similarities to the contemporary azhdarchid Hatzegopteryx have also been noted.[17]

Systematics

[edit]

Azhdarchids were originally classified as close relatives of Pteranodon due to their long, toothless beaks. Others have suggested they were more closely related to the toothy ctenochasmatids (which include filter-feeders like Ctenochasma and Pterodaustro), but this classification is largely obsolete. Currently it is widely agreed that azhdarchids were closely related to pterosaurs such as chaoyangopterids, thalassodromids, and tapejarids, all of which belong to the superfamily Azhdarchoidea.[18][19][20][21][22][23]

Life reconstructions of the giant azhdarchids Hatzegopteryx (left), Quetzalcoatlus (middle), and Arambourgiania (right) attempting to feed on the ground

Phylogeny

[edit]

Two of the most complete phylogenetic results that include the family Azhdarchidae are presented below. The first, published in 2021 by Brian Andres, recovered Montanazhdarcho as the sister taxon to Azhdarchidae within the clade Azhdarchiformes. Within Azhdarchidae, two different subfamilies were recovered, the Azhdarchinae and the Quetzalcoatlinae. The former contains azhdarchids closer related to Azhdarcho and are smaller in size, while the latter contains azhdarchids closer to Quetzalcoatlus and are generally much larger in size.[19]

Azhdarchiformes

In a more comprehensive 2025 study (using a phylogenetic matrix modified from Pêgas (2024)[20] and Zhou et al (2025).[21]), Pêgas et al. recovered Azhdarchidae as the sister taxon to the family Alanqidae within the clade Azhdarchiformes. The authors also proposed an updated nomenclatural scheme for azhdarchids, including the naming of three new clades. Herein, the new clade Quetzalcoatlida was preferred over Quetzalcoatlinae, comprising the new clades Hatzegopterygia (taxa closer to Hatzegopteryx than Quetzalcoatlus) and Quetzalcoatlini (taxa closer to Quetzalcoatlus than Hatzegopteryx). Quetzalcoatlida comprised more azhdarchid genera within it, while the subfamily Azhdarchinae was not recovered. Various azhdarchids found within the Quetzalcoatlinae by Andres in 2021 have been found as non-quetzalcoatlidans in this study. These include Aralazhdarcho, Eurazhdarcho, Wellnhopterus, and Phosphatodraco, which together form the newly-named subgroup Phosphatodraconia, as well as Zhejiangopterus, Mistralazhdarcho, and Aerotitan, which form another unnamed subgroup. Azhdarcho is recovered as the sister taxon to Quetzalcoatlida.[24]

In 2025, Henry N. Thomas and Skye N. McDavid performed an extensive revision of pterosaur phylogenetics with a focus on Azhdarchomorpha. Their results aligned with the previous analyses by Pêgas et al. (2025)[24] in supporting the clades Phosphatodraconia, Hatzegopterygia, and Quetzalcoatlini. Thomas and McDavid informally recognized the clade comprising Zhejiangopterus, Mistralazhdarcho, and Aerotitan as the 'Zhejiangopterus clade'. The results differ, however, in finding Quetzalcoatlus to be polyphyletic, with the type species Q. nothropi being sister to Thanatosdrakon while 'Q'. lawsoni claded in a polytomy with the 'Tous pterosaur' and other unnamed specimens that was recovered as sister to Thanatosdrakon and Q. nothropi. They also name the clade Serpennata which includes all the quetzalcoatlins with extremely elongate necks, excluding Nipponopterus and Gobiazhdarcho. Within this clade, the authors recognized two main groupings: the 'Arambourgiania clade' (comprising Arambourgiania and Infernodrakon) and the 'Quetzalcoatlus clade' (comrpising Q. nothropi, Thanatosdrakon, and 'Q'. lawsoni). A reproduction of their phylogenetic tree is provided below:[25]

Azhdarchiformes
Alanqidae
Azhdarchidae
Phosphatodraconia
'Zhejiangopterus clade'

Azhdarcho lancicollis

Quetzalcoatlinae

Cryodrakon boreas

Hatzegopterygia

Tsogtopteryx mongoliensis

Albadraco tharmisensis

Bakonydraco spp.

LPB R.2395 ('Pui azhdarchid')

Hatzegopteryx thambemba

LPB R.2347

EME 315 ('Râpa Roşie azhdarchid')

Quetzalcoatlini

Former and possible azhdarchid genera

[edit]

There have been many pterosaur genera that were once assigned to the Azhdarchidae, but have since been reassigned to other pterosaur groups. Alanqa and Argentinadraco, for example, have sometimes been referred to Azhdarchidae,[18][27][28] but recent phylogenetic studies have recovered these as either forming their own family, the Alanqidae,[29][22][20][21] or within the family Thalassodromidae.[23][19] The genus Bakonydraco, also initially classified as an azhdarchid,[18] has been recovered as a tapejarid in many recent studies.[22][20][21] Volgadraco and Bogolubovia, both assigned to this family in at least one study,[18][30] are currently considered pteranodontians.[31][32] The pterosaur Montanazhdarcho has also been reclassified as a non-azhdarchid,[33] with phylogenetic analyses recovering it as either an alanqid,[22] or as a basal azhdarchiform.[23][19]

The genus Navajodactylus was tentatively assigned to this family,[34] but its status has been questioned.[5] The pterosaur Tethydraco has been suggested to have been an azhdarchid in one study,[35] but this assignment has not been found in other analyses, with most finding it as a pteranodontian.[31][23][19]

References

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  1. ^ Watson, Traci (2016-08-30). "Cat-Size Flying Reptile Shakes Up Pterosaur Family Tree". National Geographic. Archived from the original on 2016-09-01.
  2. ^ a b Nesov, L. A. (1984). "Upper Cretaceous pterosaurs and birds from Central Asia". Paleontologicheskii Zhurnal. 1984 (1): 47–57. Archived from the original on 2009-01-05.
  3. ^ Slack KE, Jones CM, Ando T, et al. (June 2006). "Early Penguin Fossils, Plus Mitochondrial Genomes, Calibrate Avian Evolution". Molecular Biology and Evolution. Molecular Biology and Evolution. 23 (6): 1144–55. pp. 1144–1155. doi:10.1093/molbev/msj124. PMID 16533822. Retrieved 2023-07-25.{{cite web}}: CS1 maint: location (link)
  4. ^ Agnolin, Federico L. & Varricchio, David (2012). "Systematic reinterpretation of Piksi barbarulna Varricchio, 2002 from the Two Medicine Formation (Upper Cretaceous) of Western USA (Montana) as a pterosaur rather than a bird" (PDF). Geodiversitas. 34 (4): 883–894. doi:10.5252/g2012n4a10. S2CID 56002643. Archived from the original (PDF) on 2013-01-15.
  5. ^ a b Wilton, Mark P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. ISBN 0691150613.
  6. ^ Kellner, A. W. A.; Langston, W. (1996). "Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas". Journal of Vertebrate Paleontology. 16 (2): 222–231. Bibcode:1996JVPal..16..222K. doi:10.1080/02724634.1996.10011310.
  7. ^ Chatterjee, S.; Templin, R. J. (2004). Posture, locomotion, and paleoecology of pterosaurs. GSA Special Papers. Vol. 376. pp. 1–64. doi:10.1130/0-8137-2376-0.1. ISBN 978-0-8137-2376-1.
  8. ^ Ősi, A.; Weishampel, D.B.; Jianu, C.M. (2005). "First evidence of azhdarchid pterosaurs from the Late Cretaceous of Hungary" (PDF). Acta Palaeontologica Polonica. 50 (4): 777–787.
  9. ^ Humphries, S.; Bonser, R.H.C.; Witton, M.P.; Martill, D.M. (2007). "Did pterosaurs feed by skimming? Physical modelling and anatomical evaluation of an unusual feeding method". PLOS Biology. 5 (8) e204. doi:10.1371/journal.pbio.0050204. PMC 1925135. PMID 17676976.
  10. ^ Witton, Mark P.; Naish, Darren; McClain, Craig R. (28 May 2008). "A Reappraisal of Azhdarchid Pterosaur Functional Morphology and Paleoecology". PLOS ONE. 3 (5) e2271. Bibcode:2008PLoSO...3.2271W. doi:10.1371/journal.pone.0002271. PMC 2386974. PMID 18509539.
  11. ^ Veldmeijer, Andre J.; Witton, Mark; Nieuwland, Ilja (2012). Pterosaurs. Sidestone Press. ISBN 978-90-8890-093-8.
  12. ^ Naish, D.; Witton, M.P. (2017). "Neck biomechanics indicate that giant Transylvanian azhdarchid pterosaurs were short-necked arch predators". PeerJ. 5 e2908. doi:10.7717/peerj.2908. PMC 5248582. PMID 28133577.
  13. ^ Martill, D.M.; Ibrahim, N. (2015). "An unusual modification of the jaws in cf. Alanqa, a mid-Cretaceous azhdarchid pterosaur from the Kem Kem beds of Morocco" (PDF). Cretaceous Research. 53: 59–67. Bibcode:2015CrRes..53...59M. doi:10.1016/j.cretres.2014.11.001.
  14. ^ Witton, M.P.; Habib, M.B. (2010). "On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness". PLOS ONE. 5 (11) e13982. Bibcode:2010PLoSO...513982W. doi:10.1371/journal.pone.0013982. PMC 2981443. PMID 21085624.
  15. ^ Martin-Silverstone, Elizabeth; Witton, Mark P.; Arbour, Victoria M.; Currie, Philip J. (2016). "A small azhdarchoid pterosaur from the latest Cretaceous, the age of flying giants". Royal Society Open Science. 3 (8) 160333. Bibcode:2016RSOS....360333M. doi:10.1098/rsos.160333. PMC 5108964. PMID 27853614.
  16. ^ Prondvai, E.; Bodor, E. R.; Ösi, A. (2014). "Does morphology reflect osteohistology-based ontogeny? A case study of Late Cretaceous pterosaur jaw symphyses from Hungary reveals hidden taxonomic diversity" (PDF). Paleobiology. 40 (2): 288–321. Bibcode:2014Pbio...40..288P. doi:10.1666/13030. S2CID 85673254.
  17. ^ "World's largest pterodactyl skeleton goes on show in Germany". The Local Germany. 2018-03-23. Archived from the original on 2018-03-26.
  18. ^ a b c d Averianov, Alexander (2014-08-11). "Review of taxonomy, geographic distribution, and paleoenvironments of Azhdarchidae (Pterosauria)". ZooKeys (432): 1–107. Bibcode:2014ZooK..432....1A. doi:10.3897/zookeys.432.7913. PMC 4141157. PMID 25152671.
  19. ^ a b c d e Andres, Brian (2021-12-07). "Phylogenetic systematics of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea)". Journal of Vertebrate Paleontology. 41 (sup1): 203–217. Bibcode:2021JVPal..41S.203A. doi:10.1080/02724634.2020.1801703. ISSN 0272-4634. S2CID 245078533.
  20. ^ a b c d Pêgas, Rodrigo V. (2024-06-10). "A taxonomic note on the tapejarid pterosaurs from the Pterosaur Graveyard site (Caiuá Group, ?Early Cretaceous of Southern Brazil): evidence for the presence of two species". Historical Biology. 37 (5): 1277–1298. doi:10.1080/08912963.2024.2355664. ISSN 0891-2963.
  21. ^ a b c d Zhou, Xuanyu; Ikegami, Naoki; Pêgas, Rodrigo V.; Yoshinaga, Toru; Sato, Takahiro; Mukunoki, Toshifumi; Otani, Jun; Kobayashi, Yoshitsugu (2024-11-16). "Reassessment of an azhdarchid pterosaur specimen from the Mifune Group, Upper Cretaceous of Japan". Cretaceous Research. 167 106046. doi:10.1016/j.cretres.2024.106046. ISSN 0195-6671.
  22. ^ a b c d Pêgas, R. V.; Zhoi, X.; Jin, X.; Wang, K.; Ma, W. (2023). "A taxonomic revision of the Sinopterus complex (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota, with the new genus Huaxiadraco". PeerJ. 11 e14829. e14829. doi:10.7717/peerj.14829. PMC 9922500. PMID 36788812.
  23. ^ a b c d Longrich, Nicholas R.; Martill, David M.; Andres, Brian; Penny, David (2018). "Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary". PLOS Biology. 16 (3) e2001663. doi:10.1371/journal.pbio.2001663. PMC 5849296. PMID 29534059.
  24. ^ a b Pêgas, R. V.; Zhou, Xuanyu; Kobayashi, Yoshitsugu (2025). "Azhdarchid pterosaur diversity in the Bayanshiree Formation, Upper Cretaceous of the Gobi Desert, Mongolia". PeerJ. 13 e19711. doi:10.7717/peerj.19711. PMC 12447946.
  25. ^ Thomas, Henry N.; McDavid, Skye N. (5 Nov 2025). "Enter the dragons: the phylogeny of Azhdarchoidea (Pterosauria: Pterodactyloidea) and the evolution of giant size in pterosaurs". Journal of Systematic Palaeontology. 23 (1) 2569368. doi:10.1080/14772019.2025.2569368. Retrieved 5 November 2025.
  26. ^ Agnolin, Federico; Rozadilla, Sebastián; Juárez-Valieri, Rubén; Meso, Jorge (2023-10-25). "Oldest azhdarchid (Pterosauria) record from South America". Revista del Museo Argentino de Ciencias Naturales. Nueva serie (in Spanish). 25 (2): 309–314. ISSN 1853-0400.
  27. ^ Kellner, A.W.A.; Calvo, J.O. (2017). "New azhdarchoid pterosaur (Pterosauria, Pterodactyloidea) with an unusual lower jaw from the Portezuelo Formation (Upper Cretaceous), Neuquén Group, Patagonia, Argentina". Anais da Academia Brasileira de Ciências. 89 (3 suppl): 2003–2012. doi:10.1590/0001-3765201720170478. PMID 29166530.
  28. ^ Smith, R.E.; Ibrahim, N.; Longrich, N.; Unwin, D.M.; Jacobs, M.L.; Williams, C.J.; Zouhri, S.; Martill, D.M. (2023). "The pterosaurs of the Cretaceous Kem Kem Group of Morocco". PalZ. 97 (3): 519–568. Bibcode:2023PalZ...97..519S. doi:10.1007/s12542-022-00642-6.
  29. ^ Pêgas, R.V.; Holgado, B.; Ortiz David, L.D.; Baiano, M.A.; Costa, F.R. (August 21, 2021). "On the pterosaur Aerotitan sudamericanus (Neuquén Basin, Upper Cretaceous of Argentina), with comments on azhdarchoid phylogeny and jaw anatomy". Cretaceous Research. 129 104998. doi:10.1016/j.cretres.2021.104998. ISSN 0195-6671. S2CID 238725853.
  30. ^ Averianov, A.O.; Arkhangelsky, M.S.; Pervushov, E.M. (October 2008). "A New Late Cretaceous Azhdarchid (Pterosauria, Azhdarchidae) from the Volga Region". Paleontological Journal. 42 (6): 634–642. Bibcode:2008PalJ...42..634A. doi:10.1134/S0031030108060099. S2CID 129558986.
  31. ^ a b Fernandes, Alexandra E.; Mateus, Octávio; Andres, Brian; Polcyn, Michael J.; Schulp, Anne S.; Gonçalves, António Olímpio; Jacobs, Louis L. (2022). "Pterosaurs from the Late Cretaceous of Angola". Diversity. 14 (9). 741. Bibcode:2022Diver..14..741F. doi:10.3390/d14090741. hdl:10362/145845.
  32. ^ Averianov AO, Kurin AS (2022). "A new specimen of pteranodontid pterosaur Bogolubovia orientalis from the Upper Cretaceous of Penza Province, Russia". Historical Biology: An International Journal of Paleobiology. 35 (8): 1288–1296. doi:10.1080/08912963.2022.2087522. S2CID 249728681.
  33. ^ Carroll, Nathan (2015). "Reassignment of Montanazhdarcho minor as a non-azhdarchid member of the Azhdarchoidea". Journal of Vertebrate Paleontology. 35: 104. Archived from the original on 2019-12-24. Retrieved 2021-01-21.
  34. ^ Robert M. Sullivan & Denver W. Fowler (2011). "Navajodactylus boerei, n. gen., n. sp., (Pterosauria, ?Azhdarchidae) from the Upper Cretaceous Kirtland Formation (upper Campanian) of New Mexico" (PDF). Fossil Record 3. New Mexico Museum of Natural History and Science, Bulletin. 53: 393–404. Archived from the original on 2011-09-29.
  35. ^ Labita, Claudio; Martill, David M. (October 2020). "An articulated pterosaur wing from the Upper Cretaceous (Maastrichtian) phosphates of Morocco". Cretaceous Research. 119 104679. doi:10.1016/j.cretres.2020.104679. S2CID 226328607.
  • Astibia, H.; Buffetaut, E.; Buscalioni, A.D.; Cappetta, H.; Corral, C.; Estes, R.; Garcia-Garmilla, F.; Jaeger, Mazin; Jimenez-Fuentes, J.J.; Loeuff, J. Le; Mazin, J.M.; Orue-Etxebarria, X.; Pereda-Suberbiola, J.; Powell, J.E.; Rage, J.C.; Rodriguez-Lazaro, J.; Sanz, J.L.; Tong, H.; et al. (1991). "The fossil vertebrates from Lafio (Basque Country, Spain); new evidence on the composition and affinities of the Late Cretaceous continental fauna of Europe". Terra Nova. 2 (5): 460–466. doi:10.1111/j.1365-3121.1990.tb00103.x.
  • Bennett, S. C. (2000). "Pterosaur flight: the role of actinofibrils in wing function". Historical Biology. 14 (4): 255–284. Bibcode:2000HBio...14..255B. doi:10.1080/10292380009380572. S2CID 85185457.
  • Nesov, L.A. (1990). "Flying reptiles of the Jurassic and Cretaceous of the USSR and the significance of their remains for the reconstruction of palaeogeographic conditions". Bulletin of Leningrad University, Series 7, Geology and Geography (in Russian). 4 (28): 3–10.
  • Nesov, L.A. (1991). "Giant flying reptiles of the family Azhdarchidae: 11. Environment, sedirnentological conditions and preservation of remains". Bulletin of Leningrad University, Series 7, Geology and Geography (in Russian). 3 (21): 16–24.
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