formation

View of the badlands of the type locality for the North Horn Formation on North Horn Mountain.

A reconstruction of Erythrovenator jacuiensis based on a skeletal by Maurissauro. This basal theropod comes from the Late Triassic Candelária Formation of Brazil.

Chert & phosphorite in the Permian of Wyoming, USA. The Permian-aged Phosphoria Formation has a significant component of phosphorite, a scarce, phosphate-rich sedimentary rock. This material is mined in southern Idaho as a source of phosphorus for the fertilizer industry, the fireworks industry, and other uses. Phosphorites are generally considered to have >15-20% phosphate content. Texturally, phosphorites can be obviously granular, with fossil fragments or oolites or peloids or lithic fragments, or they can be composed of extremely fine-grained, phosphate-rich mud. Compositionally, the phosphate component in phosphorites is principally a mix of apatite minerals: chlorapatite (Ca5(PO4)3Cl), fluorapatite (Ca5(PO4)3F), hydroxyapatite (Ca5(PO4)3OH)), and carbonate fluorapatite (Ca10(PO4,CO3)6F2-3). Phosphorites are generally marine sedimentary rocks. They range in age from Precambrian to Holocene. In modern oceans, they tend to occur along the eastern margins of some ocean basins where deep-water upwelling occurs under areas of high biologic productivity. Stratigraphy: Rex Chert Member over Meade Peak Member, Phosphoria Formation, Roadian Stage to Wordian Stage, lower Guadalupian Series, mid-Permian Locality: roadcut on the northern side of Route 26/Route 89 at the town of Astoria Hot Springs, Snake River Canyon, southern Teton County, northwestern Wyoming, USA

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.

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_...

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.

Rebun Island lies in the Sea of Japan off the northwestern tip of Hokkaido and is part of the Rishiri-Rebun-Sarobetsu National Park. Momoiwa ("Peach Rock") was created in a relatively new era of Rebun Island's strata when underground magma pushed the earth's surface upward where it cooled into a huge spherical rock formation. Spheroidal joints (plate-shaped joints on the surface) peeled away like the skin of an onion, revealing the scree, which cooled at a slower rate than the surface, creating the columnar jointing that can be seen.

“Golden spike” at the GSSP of the Selandian stage (lower Upper Paleocene) at Zumaia section, Spanish Basque Country. The spike sits on the top plane of the uppermost limestone bed of the Aitzgorri Limestone Formation which is identical to the basal plane of the overlying red marls of the lowest part of the Itzurun Formation (right-hand outside the picture).[1]

Information sign for the GSSP of the Seelandian stage (lower Upper Paleocene) at Zumaia section, Spanish Basque Country. The sign is mounted near the “golden spike” on the top plane of the uppermost limestone bed of the Aitzgorri Limestone Formation which is identical to the basal plane of the overlying red marls of the lowest part of the Itzurun Formation (right-hand outside the picture).[1]

The productive layer of the Estonian oil shale deposit as seen in the Põhja-Kiviõli II opencast mine. The productive layer is made up of oil shale layers A through F1 together with the limestone layers in between. However, in some cases, layers F2, G and H (visible in the image, but not labeled) are also mined. The oil shale beds are marked on the image with capital letters, limestone layers are labeled with a combination of two capital letters, indicating at their location within the productive layer. Dashed lines indicate layer boundaries, which are harder to distinguish and are thus approximations. Stratigraphy: the productive layer of the Estonian oil shale deposit is part of the Kiviõli Member of the Viivikonna Formation. The formation belongs to Upper-Ordovician Kukruse Regional Stage (global Sandbian Stage). (Source reference: Heikki Bauert and Olle Hints "XI Baltic Stratigraphical Conference. Abstracts and Field Guide", Stop 4: Põhja-Kiviõli II open-pit mine, page 85, figure 4.4).

Shetwemys, Plastral remains of the podocnemidid turtle S. fajumensis (Erymnochelyini). (a–b) NHMUK R3435, anterior plastral lobe, in ventral (a) and dorsal (b) views. (c–d) NHMUK R8441, plaster cast of the specimen CGM C8509, anterior plastral lobe, in ventral (c) and dorsal (d) views. (e–f) AMNH 5093, articulated epiplastra and entoplastron, in ventral (e) and dorsal (f) views. (g–h) SMNS 11233/6, anterior plastral lobe, in ventral (g) and dorsal (h) views. (i–j) NHMUK R3103, partial anterior plastral lobe, in ventral (i) and dorsal (j) views. (k–l) SMNS 11233/5, right hypoplastron, in ventral (k) and dorsal (l) views. (m–n) SMNS 11233/3, articulated left hypoplastron and xiphiplastron, in dorsal (m) and ventral (n) views, and detail of the outer ornamental pattern (o). Gebel Quatrani Formation, Fayum depression, Egypt, Lower Oligocene (Rupelian)

Shetwemys, Shell remains of the podocnemidid turtle S. fajumensis (Erymnochelyini). (a–c) SMNS 11233/2, partial carapace, in dorsal (a), ventral (b), and left lateral (c) views. (d) Ventral view of the anterior lobe the holotype of the species, currently lost, based on the fig. 2C in plate 8 of Andrews (1903). (e–g) SMNS 12647, plastron, in ventral (e), dorsal (f), and left lateral (g) views. (g’) corresponds to an enlarged photograph of the posterior plastral lobe, in left lateral view, in which the thickness in the regions close to the hypo-xiphiplastral suture (in blue), between the pelvic scars (in green), and at the level of the anal notch (in red), have been represented by arrows (h–i), SMNS 12646, plastron, in ventral (h) and dorsal (i) views. Gebel Quatrani Formation, Fayum depression, Egypt, Lower Oligocene (Rupelian)

Shetwemys, Shell remains of the podocnemidid turtle S. fajumensis (Erymnochelyini). (a–f) AMNH 5087, carapace and partial plastron, in dorsal (a), ventral (b), anterior (c), posterior (d), left lateral (e), and right lateral (f) views. (g–h) SMNS 11233/1, partial carapace, in dorsal (g) and ventral (h) views. Gebel Quatrani Formation, Fayum depression, Egypt, Lower Oligocene (Rupelian)

Close up of the Eulithomyrmex rugosus holotype head. Museum of Comparative Zoology specimen UCM17019. Priabonian; Florissant Formation, Colorado, USA

Formation d'âge Kimmeridgien (jaune orangé) et Tithonien (Barre tithonique, en gris sur la photo). On peut remarquer que les strates ont été plissées. L'âge des mouvements tectoniques ayant déformé la structure est donc plus jeune que le Tithonien.

The GSSP for the Hirnantian stage in the ICS geological timescale (uppermost Ordovician stage), located in the Wangjiawan profile (an outcrop of black shale, brownishly weathered siliceous shale and chert layers of the Wufeng Formation) along the G241 road, about 40 km north of Yichang, Hubei, China. An exact golden spike is missing in the profile (2025) but a memorial plague marks the place. The GSSP occurs at the first appearance of fossils of the graptolite species Normalograptus extraordinarius. It was ratified in 2006.