Crétacé

Speculative reconstruction of Aoniraptor'’ from the Late Cretaceous of Argentina, here restored as a megaraptoran as recovered by most studies

Skull diagram featuring the holotype skull (ROM 1790) of the ornithomimid Rativates evadens, from the Late Cretaceous period. Abbreviations: d, dentary; f, frontal; l, lacrimal; m, maxilla; n, nasal; pm, premaxila; ps, paraphenoid.

Ceratopsipes goldenensis Lockley & Hunt, 1995 - ceratopsian dinosaur trackway in the Cretaceous of Colorado, USA. Ceratopsians are the "horned dinosaurs". They were large, quadrupedal, herbivorous dinosaurs having a beaked skull and a frill - an extension of bone behind the skull that partially covered the neck. Ceratopsian dinosaurs are known from the Jurassic and Cretaceous. The last members of the group died out at the Cretaceous-Tertiary boundary, 65 million years ago. Seen here is a ceratopsian dinosaur trackway. Ceratopsian footprints are very rare. The best examples are in Colorado's Laramie Formation, a nonmarine, coastal plain to deltaic succession of mostly mixed siliciclastic sedimentary rocks - sandstones, siltstones, claystones, and coals. The footprints here consist of convex bulges on the basal surfaces of structurally-tilted sandstone beds. The ichnospecies Ceratopsipes goldenensis was named based on footprints at this locality. The trackmaker was very likely Triceratops, the # 1 most famous ceratopsian dinosaur. From on-site signage: Triceratops Tracks Several tracks of Triceratops, or a closely related horned dinosaur were first discovered in this area and named Ceratopsipes goldenensis (meaning tracks of a horned dinosaur from Golden). By happy coincidence, the first Triceratops known to science also comes from the greater Denver area near 13th Avenue and Federal Blvd. Growing to a length of almost 25 feet, Triceratops and other members of the horned dinosaur family were herbivorous animals that roamed in herds. Their trademark horns and frills that covered their necks probably served for defense. A replica Triceratops skull is on display in the clubhouse at the Fossil Trace Golf Club. These tracks (identified by small signs) help us understand that Triceratops walked with a narrow gait and erect front limbs than with a wide, sprawling gait as previously depicted. In 1887, the first Triceratops bones known to science were also discovered locally at a site near 13th Avenue and Federal Boulevard in Denver. Nearby one may see many other traces of life such as burrows, probably made by invertebrates and impressions of plant debris. Note that you are looking at all tracks and traces from the underside - in negative aspect - what one might call a worm’s eye view. All of these trace fossils indicate that the Golden area once had a warm, temperate to subtropical climate. Classification: Animalia, Chordata, Vertebrata, Reptilia, Archosauria, Dinosauria, Ornithischia, Marginocephalia, Ceratopsia, Ceratopsidae Stratigraphy: Laramie Formation, Maastrichtian Stage, upper Upper Cretaceous Locality: outcrop along Triceratops Trail, Parfet Prehistoric Preserve, southern side of the town of Golden, Colorado, USA (~vicinity of 39° 44' 35.24" North latitude, 105° 13’ 09.69" West longitude) Some info. from: Lockley & Hunt (1995) - Ceratopsid tracks and associated ichnofauna from the Laramie Formation (Upper Cretaceous: Maastrichtian) of Colorado. Journal of Vertebrate Paleontology 15: 592-614.

Ornithischian dinosaur Stenopelix valdensis Meyer, 1857, holotype (GZG 741/2, formerly GPI Gö 741−2), from the Obernkirchen Sandstone (Early Cretaceous: Berriasian), near Bückeburg, Niedersachsen, Germany. A. Large sandstone slab. B. Interpretative outline drawing of large latex cast (prepared from large sandstone slab), showing majority of postcranial skeleton in dorsal view. C. Small sandstone slab. D. Interpretative outline drawing of small la− tex cast (prepared from small sandstone slab), showing sacrum and caudals, pelvic region and partial hindlimbs in ventral view. For clarity elements in and around the sacral region have not been labelled—these areas are shown in greater detail in Fig. 3. Roman numerals II–IV correspond to respective digits. Abbreviations: mt, metatarsals; f, femur; ?, unidentified element.

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

The hadrosaurid dinosaur Wulagasaurus dongi gen. et sp. nov. from the Upper Cretaceous Yuliangze Formation at the Wulaga quarry, China. A. Holotype GMH W184, right dentary in lateral (A1) and medial (A2) views. B. GMH W217, right dentary in lateral (B1) and medial (B2) views.

Holotype maxilla of the lambeosaurine hadrosaurid Ajnabia odysseus from the Late Cretaceous (late Maastrichtian) of Sidi Chennane, Morocco

Malefica is a hadrosaurid dinosaur from the Late Cretaceous of Texas in the United States. Like other hadrosaurs, Malefica was herbivorous, processing plant matter with their broad beaks and battery of teeth in the back of the mouth. It could grow to around 6 m in length, and weighed about 1 t. The discovery of Malefica helped to understand the distribution of hadrosaurs in Cretaceous North America, as well as evolutionary lineages between basal hadrosaurs and the more derived saurolophids.

Theiophytalia kerri Brill & Carpenter, 2006 - ornithopod dinosaur skull from the Cretaceous of Colorado, USA. (YPM 1887, public display, Garden of the Gods visitor center, Colorado Springs, Colorado, USA) This skull is the holotype and only known specimen of an entire genus of ornithopod dinosaurs, Theiophytalia. Ornithopods were herbivorous dinosaurs. From exhibit signage: A Brand New Dinosaur Species Theiophytalia kerri What we know about the dinosaur fossil - so far: It is the only Theiophytalia kerri fossil known to exist in the world. It is a brand new genus and species of dinosaur. Theiophytalia kerri means "belonging to the Garden of the Gods". "Theios" is a Greek word that means "belonging to the gods" and "phytalia" means "garden". "kerri" honors James Hutchinson Kerr (pronounced "Care"), who discovered the dinosaur fossil. Theiophytalia was a medium-sized dinosaur, measuring about 30 feet from head to tail. It was found in 1878 in the Garden of the Gods in the lower Lytle Member of the Purgatoire Rock Formation of the Dakota Group. The dinosaur fossil skull is from the Aptian-Albian Age of the Cretaceous Ear, 125 - 100 million years old. Look closely at the fossil skull. Where are the teeth located? You can see the teeth in the back of the jaw. There are no teeth in the front of the dinosaur's beak-like mouth. This is evidence that the Theiophytalia was a plant eater. It could nip and tear plants, then grind them between its tightly-packed back teeth, similar to plant-eaters of today. Timeline: Dinosaur Fossil Discovered, then Forgotten 1878 - James Kerr, geology professor at Colorado College, finds a fossil skull "in one of the ridges east of the red rocks of the Garden of the Gods." 1886 - O.C. Marsh, famous 1800s dinosaur collector from Yale University, obtains the fossil skull from James Kerr, identifies it as a Camptosaurus dinosaur, and sends the fossil to the Yale Peabody Museum in New Haven, Connecticut. 1886 - 1995 - While the dinosaur fossil skull safely rests in the Yale Museum for many decades, knowledge of its existence is forgotten in Colorado Springs. Rediscovery - 117 years later 1994 - Colorado Springs City park staff research new exhibits for the Garden of the Gods Visitor and Nature Center, set to open in 1995. They meet with Doctor Kirk Johnson, curator of paleontology at the Denver Museum of Nature & Science. 1995 - Kirk Johnson refers the park staff to his museum colleague Doctor Ken Carpenter, expert dinosaur scientist. Doctor Carpenter remembers seeing in his files "something about a dinosaur fossil found in Garden of the Gods" and mails the following article to park staff. Camptosaurus amplus No. 1887, Yale Museum, consisting of portions of the skull and lower jaw. It was collected from deposits in the Garden of the Gods, Colorado Springs, Colorado. With this specimen was found the following note in Professor O.C. Marsh's handwriting, "Part of this animal and various Sauropoda bones were taken out by Professor Kerr in 1878." A Case of Mistaken Identity Reveals a Brand New Dinosaur! 1996 - Kirk Johnson (a Yale alumnus) secures permission to hand-carry the Camptosaurus fossil from the Yale Peabody Museum to Denver so that Ken Carpenter can make a cast (a precise replica) of the fossil. Doctor Carpenter notices irregularities in the Camptosaurus fossil and decides to re-examine the fossil when his schedule permits. 1997 - The Camptosaurus fossil replica is given to the City of Colorado Springs and is exhibited at the Garden of the Gods Visitor and Nature Center. 2006 - Doctor Carpenter and his associate Kathleen Brill reassess the fossil skull and note that it differs from other Camptosaurus skulls in several significant ways, such as the narrower mouth and snout, and the position of the nasal openings, and the bony structures over the eyes. Also, microscopic identification of the rock matrix clinging to the fossil, and research of archival maps, reveal that the fossil skull was actually found in the lower Dakota Rock Formation, not the Morrison Formation as originally reported in the 1800s. The skull is from a dinosaur that lived in the Cretaceous Ear and can't be a Jurassic Era Camptosaurus. Doctor Carpenter's exacting research reveals that the dinosaur skull is a brand new genus and species of dinosaur! He names it Theiophytalia kerri. 2008 - The Theiophytalia kerri is proudly re-exhibited at the Garden of the Gods Visitor and Nature Center. Classification: Animalia, Chordata, Vertebrata, Dinosauria, Ornithischia, Ornithopoda Stratigraphy: lower Lytle Member, Purgatoire Formation, Dakota Group, Aptian to Albian Stages, upper Lower Cretaceous Locality: Garden of the Gods, Colorado Springs, Colorado, USA See info. at: en.wikipedia.org/wiki/Theiophytalia and en.wikipedia.org/wiki/Ornithopoda

Changmiania liaoningensis, an ornithopod dinosaur from the Lower Cretaceous of Lujiatun (Liaoning Province, China). (A) Holotype PMOL AD00114 in dorsal view; (B) anterior part of the holotype PMOL AD00114 in caudolateral view; (C) referred specimen PMOL LFV022 in dorsal view. Red arrows indicate the emplacement of the gastrolith clusters.

Partial skeleton of the heterodontosaurid Tianyulong confuciusi from the Lower Cretaceous Jehol Group of China. Partial skeleton mainly in right lateral view (IVPP V17090). Enlargements of subsequent figures are shown in red. Scale bar equals 10 cm.

Reconstruction of the holotype material of Silutitan sinensis (IVPP V27874), a Cretaceous euhelopid sauropod from the Chinese Shengjinkou Formation, scaled after Euhelopus zdanskyi. Silhouette modified from "Euhelopus zdanskyi Skeletal" by Gunnar Bivens (CC BY 3.0) (https://www.deviantart.com/gunnarbivens/art/Euhelopus-zdanskyi-Skeletal-833724646)

Jiangxititan a titanosaurian sauropod from the Late Cretaceous of China. Typical for a sauropod, it had a long neck and stood on four pillar-like legs to support its massive body. Jiangxititan is a member of the Lognkosauria, which include some of the largest dinosaurs known, and is one of the few from mainland Asia. The discovery of Jiangxititan demonstrates the presence of both early-diverging and late-diverging titanosauriform sauropods in that area during the Late Cretaceous.

Restoration of Dongbeititan dongi from the Early Cretaceous of China

Garumbatitan is a sauropod dinosaur from the Early Cretaceous of what is now Spain. It is classified as a basal somphospondylan - a Titanosauriform, but not a true Titanosaur.

Reconstruction of Bravasaurus arreirosorum a titanosaur dinosaur from the Late Cretaceous of Argentina