formation

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.

Specimens of Galleonosaurus dorisae n. gen. n. sp. from the Flat Rocks Sandstone in the upper Barremian, Wonthaggi Formation, Gippsland Basin, southeastern Australia: (1–2) holotype (NMV P229196), left maxilla in lateral (1) and medial (2) views; (3) NMV P208178, left maxilla in lateral view; (4) NMV P212845, left maxilla in lateral view; (5) NMV P209977, left maxilla in lateral view; (6) NMV P186440, left maxilla in lateral view; (7) NMV 208113, right maxillary tooth in labial view. Scale bars = 10 mm (1–6); 1 mm (7).

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.

Pelvis (fused ilia and pubes) of UALVP 48778, holotype of Hesperonychus elizabethae, from the late Campanian Dinosaur Park Formation of Alberta, Canada. Fossil collected by Dr. Elizabeth Nicholls. Prepared by Clive Coy. Digital photography by Nick Longrich. Additional digital editing by Nick Longrich.

Material of the dinosaur Bahariasaurus ingens (1-4, 7-18, 24-26) and indeterminate theropods (5-6, 19-23) from the Bahariya Formation of Egypt.

Arcovenator escotae (Theropoda, Abelisauridae), braincase (MHNAix-PV 2011-12) in dorsal view (Lower Argiles Rutilantes Formation, Jas Neuf Sud, Var)

Left ilium of Stokesosaurus clevelandi, Madsen 1974 (UMNH VP 7473), Morrison Formation, Utah, USA, Late Jurassic (early Tithonian).

Dentary of Echinodon becklesii from the Lower Cretaceous Purbeck Formation of England. Left dentary (NHMUK 48215b) in lateral (A), medial (B), and dorsal (C) views.

Dentary of Echinodon becklesii from the Lower Cretaceous Purbeck Formation of England. Left dentary (NHMUK 48215b) in lateral (A), medial (B), and dorsal (C) views.

Comparison of cranial features between closely related southern Laramidian taxa; (A), Akainacephalus johnsoni (UMNH VP 20202) from the Late Cretaceous Kaiparowits Formation of Utah; and (B), Nodocephalosaurus kirtlandensis (SMP VP-900) from the Late Cretaceous Kirtland Formation of New Mexico, in left lateral views. Various synapomorphies are shared with N. kirtlandensis (highlighted in black and white arrows) and includes “flaring nostrils”; enlarged, laterally projecting, loreal osteoderms that are situated directly dorsal to the external nares. Other synapomorphies include pyramid-shaped nasal and frontal osteoderms positioned on the dorsal regions of the skull. A number of significant differences have been observed between both specimens; in A. johnsoni, the anterior, and posterior supraorbital bosses form an enlarged element that is somewhat backswept, whereas in N. kirtlandensis, the posterior and anterior supraorbital bosses are clearly defined as individual osteoderms, and are much smaller in size. Additionally, the squamosal horn in Akainacephalus is very small but is prominent and tetrahedrally shaped in Nodocephalosaurus. The quadratojugal horn in Akainacephalus is massive, has a subtriangular morphology in lateral view and projects almost entirely ventral, whereas in Nodocephalosaurus, the quadratojugal horn is smaller and has a typical fin-shaped morphology. Study sites: asob, anterior supraorbital boss; ext naris, external naris; laca, lacrimal caputegulum; loca, loreal caputegulum; naca, nasal caputegulae; orb, orbit; psob, posterior supraorbital boss; qjh, quadratojugal horn; sqh, squamosal horn.

Tooth of cf. Zapsalis, with close up of denticles. Specimen UALVP 49582 from the Milk River Formation.

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.

Skeletal reconstructions of Dinosaur Park Formation caenagnathids. Skeletal reconstructions of Citipes elegans (left), Chirostenotes pergracilis (middle), and Caenagnathus collinsi (right), showing variation in skeletal representation and body size. Previously referred material is indicated in white and newly referred material is indicated in red for each taxon. Blue asterisks indicate elements that have been histologically sampled for each taxon. Citipes elegans: dentaries, metatarsal IV; Chirostenotes pergracilis: dentaries, tibia; Caenagnathus collinsi: pubis.

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.

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.