Turonian

Azhdarcho sp., ZIN PH 56/43, distal fragment of a right ulna in proximal (a), ventral (b), posterior (c), dorsal (d), anterior (e), and distal (f, stereopair) views. This specimen is from the Tyulkili locality in the northeastern Aral Sea region of Kazakhstan; Zhirkindek Formation, Upper Cretaceous (upper Turonian – Coniacian). Abbreviations: das, dorsal articulation surface; ft, groove for flexor tendon; tub, tuberculum; vf, ventral fovea. Scale bar is 10 mm.

Cervical vertebrae of rebbachisaurid sauropod Katepensaurus goicoecheai Ibiricu, Casal, Martínez, Lamanna, Luna, and Salgado, 2013a from the Cenomanian–Turonian Bajo Barreal Formation of Chubut Province, Argentina. A. UNPSJB-PV 1007/1, anterior cervical vertebra in anterior (A1) and right ventrolateral (A2) views. B. UNPSJB-PV 1007/2, anterior cervical vertebra in right lateral view. C. UNPSJB-PV 1007/3, middle cervical vertebra in right lateral view. Lateral fossae of the centrum (hypothesized as pneumatic in origin) indicated by arrows.

Alvarezsauridae gen. et sp. indet., posterior caudal vertebrae. Dzharakuduk, Uzbekistan; Bissekty Formation, Upper Cretaceous (Turonian). a-e, ZIN PH 2441/16, two vertebrae preserved in articulation, in anterior (a), dorsal (b), posterior (c), lateral (d), and ventral (e) views. f-j, ZIN PH 2442/16, vertebra missing ventral part of the centrum, in dorsal (f), lateral (g), ventral (h), anterior (i), and posterior (j).

A skull reconstruction and cranial bones from Shaochilong maortuensis, a small-bodied mid Cretaceous (Turonian) carcharodontosauri-an theropod from Inner Mongolia, China. A, skull reconstruction (courtesy of Brett Booth); B, right maxilla in lateral view (IVPP V.2885.4); C, braincase and skull roof in dorsal view (IVPP V.2885.1-2). Scale bars equal 5 centimeters.

Pterodactylus compressirostris, holotype NHMUK PV 39410 (Cenomanian / Turonian, Chalk Formation). A–D proposed lectotype, fragment of the mandibular symphysis A left lateral view B respective line drawing C dorsal view D respective line drawing. E–H referred specimen, portion of the rostrum E left lateral view F respective line drawing G ventral view H respective line drawing. Abbreviations: ch – choanae, d – dentary, m – maxillae, naof – nasoantorbital fenestra, pl – palatine, pm – premaxillae, prid – palatal ridge, sul– sulcus. Arrows indicate alveoli or teeth. Scale bar = 10 mm. Photos courtesy of The Natural History Museum.

Pterodactylus compressirostris, holotype NHMUK PV 39410 (Cenomanian / Turonian, Chalk Formation). A–D proposed lectotype, fragment of the mandibular symphysis A left lateral view B respective line drawing C dorsal view D respective line drawing. E–H referred specimen, portion of the rostrum E left lateral view F respective line drawing G ventral view H respective line drawing. Abbreviations: ch – choanae, d – dentary, m – maxillae, naof – nasoantorbital fenestra, pl – palatine, pm – premaxillae, prid – palatal ridge, sul– sulcus. Arrows indicate alveoli or teeth. Scale bar = 10 mm. Photos courtesy of The Natural History Museum.

Sidersaura is a rebbachisaurid sauropod dinosaur from the Late Cretaceous of Argentina. Rebbachisaurids are the last known dipldocoids, and lived alongside the titanosaurs until fairly late in the Cretaceous before disappearing from the fossil record, presumably going extinct. They have long tails and relatively short necks, by sauropod standards. Sidersaura one of the most recent rebbachisaurids yet found, living in the Cenomanian–Turonian ages of the Late Cretaceous. It was large for a rebbachisaurid, growing to about 20 m in length.

Cimoliopterus cuvieri. Holotype NHMUK PV 39409 (Cenomanian / Turonian, Chalk Formation), anterior part of the rostrum A right lateral view B respective line drawing C ventral view D respective line drawing. Abbreviations: m – maxillae, pm – premaxillae, pmcr – premaxillary crest, prid – palatal ridge. Arrows and numbers indicate alveoli or teeth and their respective position. Scale bar = 10 mm. Photos courtesy of The Natural History Museum.

Lonchodraco giganteus comb. n. Lectotype NHMUK PV 39412 (Cenomanian / Turonian, Chalk Formation). A–F articulated anterior parts of the rostrum and mandible A right lateral view B respective line drawing C left lateral view D respective line drawing E anterior view F respective line drawing G associated scapulocoracoid in posterior view. Abbreviations: ch – choanae, cor – coracoid, d – dentary, dcr – dentary crest, m – maxillae, pl – palatine, pm – premaxillae, pmcr – premaxillaery crest, prid – palatal ridge, sca – scapula. Arrows indicate alveoli or teeth. Scale bar = 10 mm. Photos courtesy of The Natural History Museum.

Phylogenetic relationships, chronostratigraphic, and paleoecological implications of M. intrepidus. a Graphic illustrating temporal range of North American tyrannosauroids including species-level range prior to the discovery of M. intrepidus, extension of current range, and hypothesized range based on isolated teeth12. The current gap in the North American tyrannosauroid record spans from the Tithonian to the Aptian. Faunal composition of Late Cretaceous ecosystems was established between the Albian and Turonian, as recognized by the stratigraphic appearance of major clades (see refs. 7,12 and references therein). b generalized phylogenetic relationships of Tyrannosauroidea, showing the appearance of select traits related to cursoriality in tyrannosaurs that are newly optimized as a result of the discovery of M. intrepidus. Tree topology follows this study using the modified dataset of Carr and colleagues27. Coelurus and Tanycolagreus are grafted as basal tyrannosauroids following Brusatte and colleagues5. c Stratigraphic distribution of Allosauria in North America (incl. Megaraptora but see ref. 70 for alternative hypotheses regarding this clade) documents overlap with M. intrepidus in early Late Cretaceous ecosystems leading to (d) refined calibration on the origin of late diverging tyrannosauroids and clade-level faunal turnover within apex predator roles throughout the Late Jurassic–Late Cretaceous of North America. Colored polygons are stylized call-outs and are not intended to reflect two-dimensional data. Temporal data corresponding to this figure are available in Supplementary Table 5

A skull reconstruction and cranial bones from Shaochilong maortuensis, a small-bodied mid Cretaceous (Turonian) carcharodontosauri-an theropod from Inner Mongolia, China. A, skull reconstruction (courtesy of Brett Booth); B, right maxilla in lateral view (IVPP V.2885.4); C, braincase and skull roof in dorsal view (IVPP V.2885.1-2). Scale bars equal 5 centimeters.

Simplified stratigraphic chart of the Angoumian, a Turonian sedimentary group in the northern Aquitaine Basin, France. Facies changes are not indicated.

Sidersaura is a rebbachisaurid sauropod dinosaur from the Late Cretaceous of Argentina. Rebbachisaurids are the last known dipldocoids, and lived alongside the titanosaurs until fairly late in the Cretaceous before disappearing from the fossil record, presumably going extinct. They have long tails and relatively short necks, by sauropod standards. Sidersaura one of the most recent rebbachisaurids yet found, living in the Cenomanian–Turonian ages of the Late Cretaceous. It was large for a rebbachisaurid, growing to about 20 m in length.

Phylogenetic relationships, chronostratigraphic, and paleoecological implications of M. intrepidus. a Graphic illustrating temporal range of North American tyrannosauroids including species-level range prior to the discovery of M. intrepidus, extension of current range, and hypothesized range based on isolated teeth12. The current gap in the North American tyrannosauroid record spans from the Tithonian to the Aptian. Faunal composition of Late Cretaceous ecosystems was established between the Albian and Turonian, as recognized by the stratigraphic appearance of major clades (see refs. 7,12 and references therein). b generalized phylogenetic relationships of Tyrannosauroidea, showing the appearance of select traits related to cursoriality in tyrannosaurs that are newly optimized as a result of the discovery of M. intrepidus. Tree topology follows this study using the modified dataset of Carr and colleagues27. Coelurus and Tanycolagreus are grafted as basal tyrannosauroids following Brusatte and colleagues5. c Stratigraphic distribution of Allosauria in North America (incl. Megaraptora but see ref. 70 for alternative hypotheses regarding this clade) documents overlap with M. intrepidus in early Late Cretaceous ecosystems leading to (d) refined calibration on the origin of late diverging tyrannosauroids and clade-level faunal turnover within apex predator roles throughout the Late Jurassic–Late Cretaceous of North America. Colored polygons are stylized call-outs and are not intended to reflect two-dimensional data. Temporal data corresponding to this figure are available in Supplementary Table 5

Alvarezsauridae gen. et sp. indet., posterior caudal vertebrae. Dzharakuduk, Uzbekistan; Bissekty Formation, Upper Cretaceous (Turonian). a-e, ZIN PH 2441/16, two vertebrae preserved in articulation, in anterior (a), dorsal (b), posterior (c), lateral (d), and ventral (e) views. f-j, ZIN PH 2442/16, vertebra missing ventral part of the centrum, in dorsal (f), lateral (g), ventral (h), anterior (i), and posterior (j).

Cervical vertebrae of rebbachisaurid sauropod Katepensaurus goicoecheai Ibiricu, Casal, Martínez, Lamanna, Luna, and Salgado, 2013a from the Cenomanian–Turonian Bajo Barreal Formation of Chubut Province, Argentina. A. UNPSJB-PV 1007/1, anterior cervical vertebra in anterior (A1) and right ventrolateral (A2) views. B. UNPSJB-PV 1007/2, anterior cervical vertebra in right lateral view. C. UNPSJB-PV 1007/3, middle cervical vertebra in right lateral view. Lateral fossae of the centrum (hypothesized as pneumatic in origin) indicated by arrows.