formation

Jeholopterus ningchengensus Wang, Zhou, Zhang, and Xu, 2002, IVPP V 12705, Lower Yixian Formation (Early Cretaceous), China.

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.

This reconstruction of Marambionectes molinai, found from the Lopez de Bertodano Formation, is based off of other related elasmosaurs such as Aristonectes and Nakonanectes.

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.

Tetanuran theropod Cruxicheiros newmanorum gen. et sp. nov. axial vertebrae (WARMS 15771) from the Chipping Norton Limestone Formation, Bathonian of the United Kingdom. A. Posterior cervical or anterior dorsal vertebra in posterior view. B. Partial middle−posterior dorsal vertebra in right lat− eral view showing a sagittal cross−section (B1) and in dorsal view (B2). C. Middle−distal caudal vertebra in left lateral (C1) and posterior (C2) views. D. Mid− dle−posterior dorsal neural arch in anterior (D1), right lateral (D2, D3), and posterior (D4) views. Photographs (A, B1, B2, C1, C2, D1, D2, D4) and line drawing (D3). Crossed−hatching indicates matrix and grey tone indicates broken bone.

Holotype of the polycotylid[1] plesiosaur Edgarosaurus muddi DRUCKENMILLER, 2002, (MOR 751) comprising the skull, the neck, and the left front flipper, on display in the Museum of the Rockies in Bozeman, Montana. The specimen was collected in Edgar, Carbon County, Montana, from the Shell Creek member of the Thermopolis Shale Formation, Upper Albian, uppermost Lower Cretaceous.[2]

Abelisaurid theropod Kryptops palaios gen. et sp. nov. MNN GAD1−1 from the Lower Cretaceous Elrhaz Formation of Niger. Left maxilla in lateral view; stereopair (A) and line drawing (B). Cross−hatching indicates broken bone; dashed lines indicate estimated edges.

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.

Left ilium of the camarasauromorph sauropod Brontomerus mcintoshi from the Lower Cretaceous Cedar Mountain Formation of Utah, type specimen OMNH 66430 in lateral view reconstructed from the three fragments (A), and ventral view (B).

Forearm and hand of Machairasaurus leptorhynchos Longrich et al. 2010 (Dinosauria: Theropoda: Oviraptoridae: Ingeniinae) from the Late Cretaceous Djadokhta Formation beds of Bayan Mandahu, Inner Mongolia, China. Digital photography and editing by Nick Longrich

New wing skeleton of Forfexopterus (SDUST-V1003) from Jiufotang Formation of Early Cretaceous Jehol Biota in Jianchang, western Liaoning, northeastern China. Abbreviations: ca, carpus; co, coracoid portion; hu, humerus; mc, metacarpals I–IV; mdI–III, manual digits I–III; pt, pteroid; ra, radius; sc, scapular portion; ul, ulna; wp1–4, wing phalanges 1–4.

Dinosaur National Monument is a United States National Monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green and Yampa Rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah just to the north of the town of Jensen, Utah. The nearest communities are Jensen, Utah, and Dinosaur, Colorado. The park contains over 800 paleontological sites and has fossils of dinosaurs including Allosaurus, Deinonychus, Abydosaurus (a nearly complete skull, lower jaws and first four neck vertebrae of the specimen DINO 16488 found here at the base of the Mussentuchit Member of the Cedar Mountain Formation is the holotype for the description) and various long-neck, long-tail sauropods. It was declared a National Monument on October 4, 1915. The rock layer enclosing the fossils is a sandstone and conglomerate bed of alluvial or river bed origin known as the Morrison Formation from the Jurassic Period some 150 million years old. The dinosaurs and other ancient animals were carried by the river system which eventually entombed their remains in Utah. The pile of sediments were later buried and lithified into solid rock. The layers of rock were later uplifted and tilted to their present angle by the mountain building forces that formed the Uintas during the Laramide orogeny. The relentless forces of erosion exposed the layers at the surface to be found by paleontologists. The dinosaur fossil beds (bone beds) were discovered in 1909 by Earl Douglass, a paleontologist working and collecting for the Carnegie Museum of Natural History. He and his crews excavated thousands of fossils and shipped them back to the museum in Pittsburgh, Pennsylvania for study and display. President Woodrow Wilson proclaimed the dinosaur beds as Dinosaur National Monument in 1915. The monument boundaries were expanded in 1938 from the original 80-acre (320,000 m2) tract surrounding the dinosaur quarry in Utah, to its present extent of over 200,000 acres (800 km²) in Utah and Colorado, encompassing the spectacular river canyons of the Green and Yampa. Though lesser-known than the fossil beds, the petroglyphs in Dinosaur National Monument are another treasure the monument holds. Due to problems with vandals, many of the sites are not listed on area maps. The "Wall of Bones" located within the Dinosaur Quarry building in the park consists of a steeply tilted (67° from horizontal) rock layer which contains hundreds of dinosaur fossils. The enclosing rock has been chipped away to reveal the fossil bones intact for public viewing. In July 2006, the Quarry Visitor Center was closed due to structural problems that since 1957 had plagued the building because it was built on unstable clay. The decision was made to build a new facility elsewhere in the monument to house the visitor center and administrative functions, making it easier to resolve the structural problems of the quarry building while still retaining a portion of the historic Mission 66 era exhibit hall. It was announced in April 2009 that Dinosaur National Monument would receive $13.1 million to refurbish and reopen the gallery as part of the Obama administration's $750 billion stimulus plan. The Park Service successfully rebuilt the Quarry Exhibit Hall, supporting its weight on 70-foot steel micropile columns that extend to the bedrock below the unstable clay. The Dinosaur Quarry was reopened in Fall 2011. en.wikipedia.org/wiki/Dinosaur_National_Monument en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_...

Right hind limb of the sauropodomorph dinosaur Musankwa sanyatiensis gen. et sp. nov. (NHMZ 2521) from the Pebbly Arkose Formation (Norian, Upper Triassic) of Spurwing Island, Zimbabwe. A. Right femur in posterior (A1), lateral (A2), anterior (A3), medial (A4), proximal (A5), and distal (A6) views. B. Right tibia with conjoined astragalus in anterior (B1), lateral (B2), posterior (B3), medial (B4), and proximal (B5) views.

Life restoration of the Triassic ichthyosaur Callawayia neoscapularis. Three specimens of this ichthyosaur are known, the holotype, ROM 41993, and two referred specimens, TMP 94.380.11 and 94.382.2. The skull is primarily based on ROM 41993, cross-checked against TMP 94.380.11 and TMP 94.382.2. The vertebral column is based primarily on TMP 94.382.2 as it is the most complete of these specimens, while the ribs were based on ROM 41993. The forelimbs were mainly based on those of ROM 41993, with TMP 94.380.11 used to determine their breadth. The hindlimbs were based on TMP 94.380.11, especially the more complete right hindlimb. ROM 41993 was cross-scaled with TMP 94.380.11 by the dimensions of the forelimb epipodials, which produced similar vertebral dimensions. The two TMP specimens were cross-scaled based on femoral length, also producing similar vertebral dimensions. Nicholls & Manabe (2001) stated that no wedge-shaped caudal centra supporting a tailbend were found and that there was no evidence of a bend being present, though considered that they might have existed in the gap in the preserved caudals. Since various other Triassic ichthyosaurs have since been found to have tail bends, one was illustrated here. A modest downturn of roughly 15° was illustrated, comparable to that in Guanlingsaurus, and the location of the bend within the gap in the preserved vertebrae matches well with the location of the bend in Guizhouichthyosaurus. References McGowan, C. (1994). "A new species of Shastasaurus (Reptilia: Ichthyosauria) from the Triassic of British Columbia: The most complete exemplar of the genus". Journal of Vertebrate Paleontology 14 (2): 168–179. DOI:10.1080/02724634.1994.10011550. Nicholls, E. L.; Manabe, M. (2001). "A new genus of ichthyosaur from the Late Triassic Pardonet Formation of British Columbia: Bridging the Triassic-Jurassic gap". Canadian Journal of Earth Sciences 38 (6): 983–1002. Ji, C.; Jiang, D.Y.; Hao, W.; Sun, Y. (2011). "True tailbend occurred in the Late Triassic: Evidence from ichthyosaur skeletons of South China". Acta Scientiarum Naturalium Universitatis Pekinensis 47 (2): 309–314. Shang, Q. H.; Li, C. (2009). "On the occurrence of the ichthyosaur Shastasaurus in the Guanling biota (Late Triassic), Guizhou, China". Vertebrata PalAsiatica 47 (3): 178–193.

Barsboldia sicinskii gen. et sp.n., type specimen ZPAL MgD-11110, Nemegt Formation, N Nemegt, Nemegt Basin, Gobi Desert, Mongolia 1. Right lateral view of sacrum, neural spine of last dorsal and two anterior caudals included.