Mexico

Muzquizopteryx coahuilensis (Familyː Nyctosauridae) is a species of nyctosaurid pterodactyloid pterosaur from the Late Cretaceous period (early Coniacian stage) of what is now Coahuila, Mexico.

Tyrannosauripus pillmorei, probable Tyrannosaurus footprint from w:Philmont Scout Ranch, New Mexico

Tyrannosauripus pillmorei, probable Tyrannosaurus footprint from w:Philmont Scout Ranch, New Mexico

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.

Skeletal reconstruction of Ahshislepelta minor, a small ankylosaur from the Late Cretaceous Kirtland Formation of New Mexico. While originally recovered as an ankylosaurid related to Gastonia, later analyses favored a nodosaurid position which this is based on. Based on the holotype SMP VP-1930, consisting of fragmentary shoulder, forelimb, and vertebral elements as well as several osteoderms. Unknown material filled in using Niobrarasaurus, Pawpawsaurus, Silvisaurus, Sauropelta, and Borealopelta. Total length is approximately 4.9 m through the centra. Notes: Osteoderm placement somewhat speculative, not all osteoderms and vertebral fragments are figured. References: Burns & Sullivan, 2011.

Eekaulostomus cuevasae gen. and sp. nov. from the Danian marine deposits of the Belisario Domínguez quarry, near Palenque, Chiapas, southeastern Mexico. 1, General view of IGM 4716, holotype and single specimen known. 2, Idealized line drawing of the same specimen.

Sandstones of the lower Kirtland Formation (Late Campanian), outcropping near Coal Creek. New Mexico. Photo by Nick Longrich

A fossil tree from the Coal Creek region, Fruitland Formation, latest Cretaceous (Late Campanian), San Juan Basin, New Mexico

Photograph of the holotype skull of Titanoceratops ouranos, from the late Campanian aged Kirtland/Fruitland beds of New Mexico, USA. Photograph by Nick Longrich

Diagram featuring the holotype skull (ZPAL MgD-I/105) of Tylocephale gilmorei in left lateral view. Scale bar equals 5 cm (50 mm). Based on Maryańska & Osmólska, 1974,[1] and Sullivan, 2006.[2] References ↑ (1974). "Pachycephalosauria, a new suborder of ornithischian dinosaurs". Palaeontologica Polonica (30): 45−102. ↑ (2006). "A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia)". New Mexico Museum of Natural History and Science Bulletin (35): 347–365.

Braincase of WSC 10058, holotype of Ornatops Braincase of Ornatops incantatus in digital 3D model in right lateral (A and C) and left lateral (D and F) views, with enlarged images of the right (B) and left (E) auditory regions. Credit: McDonald AT, Wolfe DG, Freedman Fowler EA, Gates TA. 2021. A new brachylophosaurin (Dinosauria: Hadrosauridae) from the Upper Cretaceous Menefee Formation of New Mexico. PeerJ 9:e11084 https://doi.org/10.7717/peerj.11084

Reconstruction of the skull of Tlatolophus galorum by sculptor Samuel Nieves Tlapaya (El Alebrije Prehistórico). Displayed in the lobby of the hosting hotel of the 12th Latin American Congress of Paleontology, held in Puebla, Mexico, during the first week of March 2025.

Plate XII(XIX). Fig. 1. Coelophysis bauri COPE. Sacrum, consisting of three vertebrae and last dorsal vertebra. COPE’s original. Triassic, New Mexico. Preserved in American Museum of Natural History, New York. Nat. size, from a cast in Tübingen. a, right lateral view; b, left lateral view; c, ventral view. Fig. 2. Thecodontosaurus skirtopodus SEELEY sp. Right humerus. Original in Vienna Hofmuseum (Coll. ADLER 1886). Upper Karroo, Cape Colony, South Africa. 1/2 nat. size, from a cast in Tübingen. Fig. 3. Same. Ditto. Proximal end of a right humerus in posterior view. 1/2 nat. size (the lateral part is missing). Fig. 4. Same. Ditto. Distal end of a left humerus in anterior view. 1/2 nat. size. Fig. 5. Same. Ditto. Distal end of a left femur in posterior view. 1/2 nat. size. Fig. 6. Same. Ditto. Proximal end of a left tibia, lateral view. 1/2 nat. size. Fig. 7. Thecodontosaurus browni SEELEY sp. Left femur in posterior view. SEELEY’s original. From the Stormberg Beds of the Telle River near Aliwal North, Cape Colony, South Africa. (From casts in the British Museum and Tübingen.) 1/2 nat. size. Fig. 8. Same. Ditto. Right femur, medial view.

Muzquizopteryx coahuilensis (Familyː Nyctosauridae) is a species of nyctosaurid pterodactyloid pterosaur from the Late Cretaceous period (early Coniacian stage) of what is now Coahuila, Mexico.

Tyrannosauripus pillmorei, probable Tyrannosaurus footprint from w:Philmont Scout Ranch, New Mexico

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.