Source: Wikipedia, the free encyclopedia.

Temporal range: Cretaceous, 92–66 Ma Possible Early Cretaceous record[1]
Reconstructed skeleton of Quetzalcoatlus northropi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Suborder: Pterodactyloidea
Clade: Azhdarchiformes
Family: Azhdarchidae
Nesov, 1984
Type species
Azhdarcho lancicollis
Nesov, 1984
  • "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 Period, though an isolated vertebra apparently from an azhdarchid is known from the Early Cretaceous as well (late Berriasian age, about 140 million years ago).[1] Azhdarchids are mainly known for including some of the largest flying animals discovered, but smaller cat-size members have also been found.[2] Originally considered a sub-family of Pteranodontidae, Nesov (1984)[3] 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,[4] but recent studies indicate a wealth of pterosaurian fauna, including pteranodontids, nyctosaurids, tapejarids and several indeterminate forms.[5] In several analyses, some taxa such as Navajodactylus, Bakonydraco and Montanazhdarcho were moved from Azhdarchidae to other clades.[6][7][8]


Artist Mark Witton's reconstruction of Hatzegopteryx hunting the ornithopod Zalmoxes.
Hatzegopteryx (A-B) compared with Arambourgiania (C) and Quetzalcoatlus (D-E). This illustrates the difference between the "blunt-beaked" azhdarchids and the "slender-beaked" forms.

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.[9]

It had been suggested azhdarchids were skimmers,[3][10] 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.[11][12][13][14][15] 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.[16] In another departure from typical azhdarchid lifestyles, the jaw of Alanqa may possibly be an adaptation to crushing shellfish and other hard foodstuffs.[17]

Azhdarchids are generally medium- to large-sized pterosaurs, with the largest achieving wingspans of 10–12 metres (33–39 ft),[18] but several small-sized species have recently been discovered.[19][20] 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.[21]


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). Currently it is widely agreed that azhdarchids were closely related to pterosaurs such as Tupuxuara and Tapejara.[citation needed]


Classification after Unwin 2006, except where noted.[22]

Reconstructed feeding posture of an azhdarchid with sagittally aligned limbs.


The most complete cladogram of azhdarchids is presented by Andres (2021):[30]


In the analysis Cretornis and Volgadraco were recovered as pteranodontians, Alanqa was recovered as a thalassodromine, and Montanazhdarcho was recovered just outside Azhdarchidae.[30]

An alternate phylogeny of Azhdarchidae was presented by Ortiz David et al. (2022) in their description of Thanatosdrakon:[31]

In this analysis, Alanqa is interpreted as a non-azhdarchid azhdarchoid closely related to Keresdrakon.[31]


  1. ^ a b Dyke, G.; Benton, M.; Posmosanu, E.; Naish, D. (2010). "Early Cretaceous (Berriasian) birds and pterosaurs from the Cornet bauxite mine, Romania". Palaeontology. 54: 79–95. doi:10.1111/j.1475-4983.2010.00997.x. S2CID 15172374.
  2. ^ Cat-Size Flying Reptile Shakes Up Pterosaur Family Tree
  3. ^ 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.
  4. ^ 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)
  5. ^ 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.
  6. ^ a b 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.
  7. ^ Andres, B.; Myers, T. S. (2013). "Lone Star Pterosaurs". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 103 (3–4): 383–398. doi:10.1017/S1755691013000303. S2CID 84617119.
  8. ^ Wilton, Mark P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. ISBN 978-0691150611.
  9. ^ Witton, M. P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press.
  10. ^ 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. doi:10.1080/02724634.1996.10011310.
  11. ^ 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 9780813723761.
  12. ^ Ősi, A.; Weishampel, D.B.; Jianu, C.M. (2005). "First evidence of azhdarchid pterosaurs from the Late Cretaceous of Hungary". Acta Palaeontologica Polonica. 50 (4): 777–787.
  13. ^ 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.
  14. ^ 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.
  15. ^ Veldmeijer, Andre J.; Witton, Mark; Nieuwland, Ilja (2012). Pterosaurs. Sidestone Press. ISBN 9789088900938.
  16. ^ 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.
  17. ^ 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. doi:10.1016/j.cretres.2014.11.001.
  18. ^ 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.
  19. ^ 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.
  20. ^ 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. doi:10.1666/13030. S2CID 85673254.
  21. ^ "World's largest pterodactyl skeleton goes on show in Germany". The Local Germany. 2018-03-23.
  22. ^ Unwin, David M. (2006). The Pterosaurs: From Deep Time. New York: Pi Press. p. 273. ISBN 0-13-146308-X.
  23. ^ Ibrahim, N.; Unwin, D.M.; Martill, D.M.; Baidder, L.; Zouhri, S. (2010). Farke, Andrew Allen (ed.). "A New Pterosaur (Pterodactyloidea: Azhdarchidae) from the Upper Cretaceous of Morocco". PLOS ONE. 5 (5): e10875. Bibcode:2010PLoSO...510875I. doi:10.1371/journal.pone.0010875. PMC 2877115. PMID 20520782.
  24. ^ Averianov, A.O. (2007). "New records of azhdarchids (Pterosauria, Azhdarchidae) from the late Cretaceous of Russia, Kazakhstan, and Central Asia" (PDF). Paleontological Journal. 41 (2): 189–197. doi:10.1134/S0031030107020098. S2CID 128637719.
  25. ^ Averianov, A.O. (2010). "The osteology of Azhdarcho lancicollis Nessov, 1984 (Pterosauria, Azhdarchidae) from the Late Cretaceous of Uzbekistan" (PDF). Proceedings of the Zoological Institute of the Russian Academy of Sciences. 314 (3): 246–317.
  26. ^ Vremir, M. T. S.; Kellner, A. W. A.; Naish, D.; Dyke, G. J. (2013). Viriot, Laurent (ed.). "A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution". PLOS ONE. 8 (1): e54268. Bibcode:2013PLoSO...854268V. doi:10.1371/journal.pone.0054268. PMC 3559652. PMID 23382886.
  27. ^ Romain Vullo; Géraldine Garcia; Pascal Godefroit; Aude Cincotta; Xavier Valentin (2018). "Mistralazhdarcho maggii, gen. et sp. nov., a new azhdarchid pterosaur from the Upper Cretaceous of southeastern France". Journal of Vertebrate Paleontology. 38 (4): (1)-(16). doi:10.1080/02724634.2018.1502670. S2CID 91265861.
  28. ^ Averianov, A.O.; Arkhangelsky, M.S.; Pervushov, E.M. (2008). "A New Late Cretaceous Azhdarchid (Pterosauria, Azhdarchidae) from the Volga Region". Paleontological Journal. 42 (6): 634–642. doi:10.1134/S0031030108060099. S2CID 129558986.
  29. ^ 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.
  30. ^ a b Andres, Brian (2021-12-07). "Phylogenetic systematics of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea)". Journal of Vertebrate Paleontology. 41 (sup1): 203–217. doi:10.1080/02724634.2020.1801703. ISSN 0272-4634. S2CID 245078533.
  31. ^ a b Ortiz David, Leonardo D.; González Riga, Bernardo J.; Kellner, Alexander W. A. (12 April 2022). "Thanatosdrakon amaru, gen. ET SP. NOV., a giant azhdarchid pterosaur from the upper Cretaceous of Argentina". Cretaceous Research. 135: 105228. doi:10.1016/j.cretres.2022.105228. S2CID 248140163. Retrieved 12 April 2022.
  • 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. 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.