Maastrichtian

The Maastrichtian, Transylvanian giant azhdarchid pterosaur Hatzegopteryx sp. preys on the rhabdodontid iguanodontian Zalmoxes. Because large predatory theropods are unknown on Late Cretaceous Haţeg Island, giant azhdarchids may have played a key role as terrestrial predators in this community.

Representative taxa from the latest Campanian–Maastrichtian faunas from Transylvania, western Romania. A–B Nidophis insularis (Serpentes, Madtsoiidae), articulated vertebrae (LPB (FGGUB) v.547/2) in left lateral (A) and dorsal (B) views (Densuş-Ciula Formation, Tuştea, Haţeg Basin; photo by Ştefan Vasile) C Allodaposuchus precedens (Eusuchia, ?Hylaeochampsidae), skull (PSMUBB V 438) in dorsal view (Sebeş = Şard Formation, Oarda de Jos, southwestern Transylvanian Basin; photo by Vlad Codrea/Massimo Delfino) D Theriosuchus sympiestodon (Mesoeucrocodylia, Atoposauridae), right maxilla (MCDRD 793) in lateral view (Sînpetru Formation, Sînpetru, Haţeg Basin) E–F Indeterminate titanosaur (?Magyarosaurus dacus) (Sauropoda, Titanosauria), isolated osteoderm (LPB (FGGUB) R.1410) in dorsal (E) and lateral (F) views (Sînpetru Formation, Sînpetru, Haţeg Basin) G Indeterminate ornithuran bird (Aves, Ornithurae), incomplete left tibiotarsus (LPB (FGGUB) R.1902) in anterior view (Densuş-Ciula Formation, Vălioara, Haţeg Basin) H Balaur bondoc (Theropoda, Dromaeosauridae), articulated left distal hindlimb (EME PV.313) in lateral view (Sebeş = Şard Formation, Sebeş-Glod, southewestern Transylvanian Basin; photo by Mick Ellison) I Zalmoxes robustus (Ornithopoda, Rhabdodontidae), right dentary (NHMUK R.3407) in medial view (Sînpetru Formation, Sînpetru, Haţeg Basin) J Telmatosaurus transsylvanicus (Hadrosauria), right maxilla (MFGI unnumbered) in lateral view (Sînpetru Formation, Sînpetru, Haţeg Basin) K Indeterminate nodosaurid – Struthiosaurus transylvanicus or new taxon – (Ankylosauria, Nodosauridae), isolated tooth (LPB (FGGUB) R.2182) in medial view (Sînpetru Formation, Sînpetru, Haţeg Basin) L Barbatodon transylvanicus (Multituberculata, Kogaionidae), right maxilla (LPB (FGGUB) M.1635) in medial view (Sînpetru Formation, Pui, Haţeg Basin). Scale bars equal 1 mm in A, B; 5 mm in K; 1 cm in G, L; 2 cm in D; and 5 cm in C, E, F, H, I, J.

World map showing Late Cretaceous metatherian locales. Europe 1. Font-de-Benon quarry, Archingeay-Les Nouillers (Cenomanian, Late Cretaceous), Charente-Maritime, southwestern France (Vullo et al. 2009) 2. Valkenburg Member, Maastricht Formation (late Maastrichtian, Late Cretaceous), southern Limburg, The Netherlands (Martin et al. 2005) Asia 3. Yixian Formation, China (Barremian, Early Cretaceous) 4. Bissekty Formation, Kyzylkum Desert, Uzbekistan (Turonian, Late Cretaceous) 5. Darbasa Formation, southern Kazakhstan (Campanian, Late Cretaceous) 6. Grey Mesa locality (Averianov 1997) 7. Barun Goyot Formation, Umuni Gobi, Mongolia (Campanian, Late Cretaceous) 8. Nemegt Formation, Omnogov, Mongolia (Maastrichtian, Late Cretaceous) 9. Djadokhta Formation, Mongolia (Campanian, Late Cretaceous) North America Alaska 9. Prince Creek Formation, Alaska (early Maastrichtian, Late Cretaceous) Alberta and Saskatchewan, Canada 10. Milk River Formation, southern Alberta, Canada (late Santonian, Late Cretaceous) 11. Oldman Formation, southern Alberta, Canada (Campanian, Late Cretaceous) 12. Dinosaur Park Formation, southern Alberta, Canada (late Campanian, Late Cretaceous) 13. Horseshoe Canyon Formation, southern Alberta, Canada (early Maastrichtian, Late Cretaceous) 14. St. Mary River Formation, Alberta and northwestern Montana (early Maastrichtian, Late Cretaceous) 15. Scollard Formation, Alberta (late Maastrichtian, Late Cretaceous) 16. Frenchman Formation, Saskatchewan (late Maastrichtian, Late Cretaceous) Montana and North Dakota 17. Judith River Formation (late Campanian, Late Cretaceous) 18. Two Medicine Formation (late Campanian, Late Cretaceous) 19. Hell Creek Formation, Montana and North Dakota (late Maastrichtian, Late Cretaceous) South Dakota 20. Fox Hills Formation, South Dakota (late Maastrichtian, Late Cretaceous) 21. Hell Creek Formation, South Dakota (late Maastrichtian, Late Cretaceous) Wyoming 22. “Mesa Verde Formation” (late Campanian, Late Cretaceous) 23. Lance Formation, Wyoming (late Maastrichtian, Late Cretaceous) 24. Ferris Formation, Wyoming (late Maastrichtian, Late Cretaceous) Utah 25. Cedar Mountain Formation (Albian-Cenomanian) 26. Dakota Formation fauna (late Cenomanian, Late Cretaceous) 27. Smoky Hollow Member, Straight Cliffs Formation (Turonian, Late Cretaceous) 28. John Henry Member, Straight Cliffs Formation (Coniacian-Santonian, Late Cretaceous) 29. Wahweap Formation (early-middle Campanian, Late Cretaceous) 30. Kaiparowits Formation (late Campanian, Late Cretaceous) 31. Iron Springs Formation fauna, southern Utah (Turonian – Santonian, Late Cretaceous) 32. North Horn Formation, Utah (late Maastrichtian, Late Cretaceous) Colorado 33. Williams Fork Formation, Colorado (late Campanian-early Maastrichtian) 34. Laramie Formation, northeastern Colorado (late Maastrichtian, Late Cretaceous) Baja California Del Norte, Mexico 35. El Gallo Formation (late Campanian, Late Cretaceous) (Clemens 1980; Lillegraven 1972; Lillegraven 1976) New Mexico 36. Fruitland and lower Kirtland Formation, San Juan Basin (late Campanian, Late Cretaceous) 37. Naashoibito Member, Kirtland Formation, New Mexico (late Maastrichtian, Late Cretaceous) Oklahoma 38. Antlers Formation, Texas and Oklahoma (Aptian-Albian, Early Cretaceous) Texas 39. Aguja Formation, West Texas (late Campanian, Late Cretaceous) New Jersey 40. Marshalltown Formation, New Jersey (Campanian, Late Cretaceous) Szalay 1994)

World map showing Late Cretaceous metatherian locales. Europe 1. Font-de-Benon quarry, Archingeay-Les Nouillers (Cenomanian, Late Cretaceous), Charente-Maritime, southwestern France (Vullo et al. 2009) 2. Valkenburg Member, Maastricht Formation (late Maastrichtian, Late Cretaceous), southern Limburg, The Netherlands (Martin et al. 2005) Asia 3. Yixian Formation, China (Barremian, Early Cretaceous) 4. Bissekty Formation, Kyzylkum Desert, Uzbekistan (Turonian, Late Cretaceous) 5. Darbasa Formation, southern Kazakhstan (Campanian, Late Cretaceous) 6. Grey Mesa locality (Averianov 1997) 7. Barun Goyot Formation, Umuni Gobi, Mongolia (Campanian, Late Cretaceous) 8. Nemegt Formation, Omnogov, Mongolia (Maastrichtian, Late Cretaceous) 9. Djadokhta Formation, Mongolia (Campanian, Late Cretaceous) North America Alaska 9. Prince Creek Formation, Alaska (early Maastrichtian, Late Cretaceous) Alberta and Saskatchewan, Canada 10. Milk River Formation, southern Alberta, Canada (late Santonian, Late Cretaceous) 11. Oldman Formation, southern Alberta, Canada (Campanian, Late Cretaceous) 12. Dinosaur Park Formation, southern Alberta, Canada (late Campanian, Late Cretaceous) 13. Horseshoe Canyon Formation, southern Alberta, Canada (early Maastrichtian, Late Cretaceous) 14. St. Mary River Formation, Alberta and northwestern Montana (early Maastrichtian, Late Cretaceous) 15. Scollard Formation, Alberta (late Maastrichtian, Late Cretaceous) 16. Frenchman Formation, Saskatchewan (late Maastrichtian, Late Cretaceous) Montana and North Dakota 17. Judith River Formation (late Campanian, Late Cretaceous) 18. Two Medicine Formation (late Campanian, Late Cretaceous) 19. Hell Creek Formation, Montana and North Dakota (late Maastrichtian, Late Cretaceous) South Dakota 20. Fox Hills Formation, South Dakota (late Maastrichtian, Late Cretaceous) 21. Hell Creek Formation, South Dakota (late Maastrichtian, Late Cretaceous) Wyoming 22. “Mesa Verde Formation” (late Campanian, Late Cretaceous) 23. Lance Formation, Wyoming (late Maastrichtian, Late Cretaceous) 24. Ferris Formation, Wyoming (late Maastrichtian, Late Cretaceous) Utah 25. Cedar Mountain Formation (Albian-Cenomanian) 26. Dakota Formation fauna (late Cenomanian, Late Cretaceous) 27. Smoky Hollow Member, Straight Cliffs Formation (Turonian, Late Cretaceous) 28. John Henry Member, Straight Cliffs Formation (Coniacian-Santonian, Late Cretaceous) 29. Wahweap Formation (early-middle Campanian, Late Cretaceous) 30. Kaiparowits Formation (late Campanian, Late Cretaceous) 31. Iron Springs Formation fauna, southern Utah (Turonian – Santonian, Late Cretaceous) 32. North Horn Formation, Utah (late Maastrichtian, Late Cretaceous) Colorado 33. Williams Fork Formation, Colorado (late Campanian-early Maastrichtian) 34. Laramie Formation, northeastern Colorado (late Maastrichtian, Late Cretaceous) Baja California Del Norte, Mexico 35. El Gallo Formation (late Campanian, Late Cretaceous) (Clemens 1980; Lillegraven 1972; Lillegraven 1976) New Mexico 36. Fruitland and lower Kirtland Formation, San Juan Basin (late Campanian, Late Cretaceous) 37. Naashoibito Member, Kirtland Formation, New Mexico (late Maastrichtian, Late Cretaceous) Oklahoma 38. Antlers Formation, Texas and Oklahoma (Aptian-Albian, Early Cretaceous) Texas 39. Aguja Formation, West Texas (late Campanian, Late Cretaceous) New Jersey 40. Marshalltown Formation, New Jersey (Campanian, Late Cretaceous) Szalay 1994)

Map of Cretaceous-aged dinosaur fossil localities of Mongolia. Gobihadros mongoliensis was collected from Bayshin Tsav in Area C. Open squares indicate Late Cretaceous sites, solid squares represent Early Cretaceous localities. Abbreviations: A, Localities of Western Gobi Desert in Mongolia, mainly group of localities of Nemegtian age (early Maastrichtian), Late Cretaceous; B, Localities of Central Gobi Desert in Mongolia, mainly Djadokhtian age (Campanian), Late Cretaceous; C & D- Localities of Eastern Gobi Desert in Mongolia, mainly Baynshirenian age (Cenomanian-Santonian), Late Cretaceous. Figure has been modified from Tsogtbaatar et al. 2014, Figure 1 [24].

Life reconstruction of a pair of Galgadraco zephyrius in a late Maastrichtian environment, showcasing the palaeobiota of the Serra da Galga Geosite. Artwork by Matheus Gadelha.

Plotosaurus bennisoni is a mosasaur from the Upper Cretaceous (Maastrichtian) North America.

Life restoration of the mosasaurine mosasaurid Eremiasaurus, with unknown portions and soft tissues based primarily on Prognathodon and supplemented with Mosasaurus where needed. References Leblanc, A.R.H.; Caldwell, M.W.; Bardet, N. (2012). "A new mosasaurine from the Maastrichtian (Upper Cretaceous) phosphates of Morocco and its implications for mosasaurine systematics". Journal of Vertebrate Paleontology 32 (1): 82–104. Lindgren, J.; Kaddumi, H.; Polcyn, M. (2013). "Soft tissue preservation in a fossil marine lizard with a bilobed tail fin". Nature Communications 4: 2423. DOI:10.1038/ncomms3423. Konishi, T.; Brinkman, D.; Massare, J.A.; Caldwell, M.W. (2011). "New exceptional specimens of Prognathodon overtoni (Squamata, Mosasauridae) from the upper Campanian of Alberta, Canada, and the systematics and ecology of the genus". Journal of Vertebrate Paleontology 31 (5): 1026–1046. Russell, D.A. (1967). "Systematics and morphology of American mosasaurs". Bulletin of the Peabody Museum of Natural History 23: 1–241.

Kaikaifilu pectorals, done on inkscape. Based on pictures and diagrams from "Kaikaifilu hervei gen. et sp. nov., a new large mosasaur (Squamata, Mosasauridae) from the upper Maastrichtian of Antarctica. Cretaceous Research".

Reconstructed skull of Jaxartosaurus aralensis Riabinin, 1937. Only a posterior portion of the skull, as well as a surangular is known, with the rest of the skull being based mostly upon File:Aralosaurus skull.png. Jaxartosaurus is currently classified as a basal lambeosaurine, more derived than Aralosaurini, but more primitive than Parasaurolophini and Lambeosaurini. It might be more derived than Tsintaosaurini (Godefroit et al., 2004). References: Riabinin, A.M. (1937). "A New Finding of Dinosaurs in the Trans-Baikal Region". Ezhegodn. Vserossijskogo Palaeont. Obstcg. 11: 142–144 Godefroit, P.; Bolotsky, Y.L.; Van Itterbeeck, J. (2004). "The lambeosaurine dinosaur Amurosaurus riabinini, from the Maastrichtian of Far Eastern Russia". Acta Palaeontologica Polonica 49(4): 585–618

Paludititan nalatzensis (UBB NVM1-43), Maastrichtian, Haţeg Basin, Romania. Scale bar equals 10 cm.

Skull of the mosasaurid squamate Thalassotitan atrox from the late Maastrichtian of Sidi Daoui, Ouled Abdoun Basin, Khouribga Province, Morocco, North Africa.

Digital illustration of the Sauropod Dinosaur Isisaurus colberti from the Late Cretaceous (Maastrichtian) of India (72.2-66 MYA). References include Jain & Bandyopadhyay (1997), several papers from Wilson et al. and skeletal reconstruction by Scott Hartman. Illustrated by Ansh Saxena. About Isisaurus– Isisaurus colberti (=Titanosaurus colberti) was a species of Titanosaurian Sauropod Dinosaur from the Late Cretaceous (Maastrichtian) age in the Indian Subcontinent. Isisaurus lived sympatrically with another Titanosaurian Sauropod Jainosaurus. It also lived alongside Theropods like Rajasaurus, Rahiolisaurus, Indosuchus etc. Remains of Isisaurus come from the Lameta formation of Central India.

Drawing of lectoholotype skull BMNH R.3386 (desigated by Weishampel et al., 1993)[1][2] of Limnosaurus transsylvanicus NOPCSA 1900 (later renamed Telmatosaurus transsylvanicus), a basal hadrosaurid dinosaur from the Late Maastrichtian (latest Upper Cretaceous) Sanpetru Formation of West Central Romania.