fossile
Nature du spécimen223 image(s) · 128 Actualités
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Reconstruction of Makhaira rossica based on Late Jurassic pliosaurids and mid-Cretaceos brachauchenines; the orange coloured parts indicate fossils preserved in YKM 68249/1-10.
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
Elasmobranchs teeth from the Thanetian phosphatic serie of Jebel Dyr (Algerian-Tunisian border area); 14. Nebrius bequaerti; 15. Archaeomanta priemi; 16. Burnhamia daviesi; 17. Ginglymostoma subafricanum; 18. Myliobatis sulcidens; 21. Hemiscyllium daimeriesi; 23. Squatiscyllium nigeriensis. a: labial; b: lingual; c: lateral; d: occlusal; e: oral; f: basilar views.
Elasmobranchs teeth from the Thanetian phosphatic serie of Jebel Dyr (Algerian-Tunisian border area); 7. Brachycarcharias lerichei; 8. Anomotodon novus; 9. Mustelus biddlei 10. Brachycarcharias lerichei; 11. Mennerotodus sp; 12. Abdounia beaugei; 13. Galeorhinus mesetaensis. a: labial; b: lingual; c: lateral views.
Elasmobranchs teeth from the Thanetian phosphatic serie of Jebel Dyr (Algerian-Tunisian border area); 1. Abdounia beaugei; 2. Palaoegaleus vincenti; 3. Galeorhinus mesetaensis; 4. Delpitoscyllium africanum; 5. Squatina prima; 6. Brachycarcharias lerichei. a: labial; b: lingual; c: lateral; d: occlusal views.
Elasmobranchs teeth and vertebrae from the Thanetian phosphatic serie of Jebel Dyr (Algerian-Tunisian border area); 23. Raja sp.; 24. Heterodontus sp.; 25. Dasyatis hexagonalis; 26. Abdounia beaugei; 27. Physogaleus secundus; 28. Carcharias hopei; 29-30. Cretalamna appendiculata; 31. Brachycarcharias lerichei; 32. Isurolamna affinis; 33-36. Sectioned fossil vertebral centrum of sharks. a: labial; b: lingual; c: lateral; d: occlusal; e: oral views.
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_...
Crommium angustatum Grateloup, 1827 fossil snail shell (apical view) from the Oligocene of France. (42 mm across at its widest) Of all the molluscs, the gastropods (snails) have made the most ecological adaptations. They can be found in almost all fundamental environments: marine, freshwater, terrestrial. Most gastropods live in the ocean, and have a single, asymmetrically coiled, external shell of calcium carbonate (CaCO3 - usually aragonite). The hard calcareous shell is the most easily fossilized part of the gastropod. The soft parts of a snail (the “slug” portion) include a well developed head having eyes, tentacles, and a mouth, and a well developed, strong, muscular foot used principally for locomotion. The shell is carried upright on the snail’s back, or is partially dragged behind. When threatened by a predator, many snails can retract their soft parts into the shell’s interior for protection. Many fossil snails in the Paleozoic rock record are often not well preserved, or are preserved as internal molds. The original aragonite of many gastropod shells is not stable on geologic time scales, and often recrystallizes or dissolves completely away. Fossil snail shells in Mesozoic and Cenozoic rocks are usually better preserved. Classification: Animalia, Mollusca, Gastropoda, Naticoidea, Ampullinidae Age: Rupelian Stage (Stampian Stage), Lower Oligocene Locality: Gaas, Landes Department, Aquitaine, southwestern France
Crommium angustatum Grateloup, 1827 fossil snail shell (apical view) from the Oligocene of France. (42 mm across at its widest) Of all the molluscs, the gastropods (snails) have made the most ecological adaptations. They can be found in almost all fundamental environments: marine, freshwater, terrestrial. Most gastropods live in the ocean, and have a single, asymmetrically coiled, external shell of calcium carbonate (CaCO3 - usually aragonite). The hard calcareous shell is the most easily fossilized part of the gastropod. The soft parts of a snail (the “slug” portion) include a well developed head having eyes, tentacles, and a mouth, and a well developed, strong, muscular foot used principally for locomotion. The shell is carried upright on the snail’s back, or is partially dragged behind. When threatened by a predator, many snails can retract their soft parts into the shell’s interior for protection. Many fossil snails in the Paleozoic rock record are often not well preserved, or are preserved as internal molds. The original aragonite of many gastropod shells is not stable on geologic time scales, and often recrystallizes or dissolves completely away. Fossil snail shells in Mesozoic and Cenozoic rocks are usually better preserved. Classification: Animalia, Mollusca, Gastropoda, Naticoidea, Ampullinidae Age: Rupelian Stage (Stampian Stage), Lower Oligocene Locality: Gaas, Landes Department, Aquitaine, southwestern France
Crommium angustatum Grateloup, 1827 fossil snail shell (abapertural view) from the Oligocene of France. (57 mm tall) Of all the molluscs, the gastropods (snails) have made the most ecological adaptations. They can be found in almost all fundamental environments: marine, freshwater, terrestrial. Most gastropods live in the ocean, and have a single, asymmetrically coiled, external shell of calcium carbonate (CaCO3 - usually aragonite). The hard calcareous shell is the most easily fossilized part of the gastropod. The soft parts of a snail (the “slug” portion) include a well developed head having eyes, tentacles, and a mouth, and a well developed, strong, muscular foot used principally for locomotion. The shell is carried upright on the snail’s back, or is partially dragged behind. When threatened by a predator, many snails can retract their soft parts into the shell’s interior for protection. Many fossil snails in the Paleozoic rock record are often not well preserved, or are preserved as internal molds. The original aragonite of many gastropod shells is not stable on geologic time scales, and often recrystallizes or dissolves completely away. Fossil snail shells in Mesozoic and Cenozoic rocks are usually better preserved. Classification: Animalia, Mollusca, Gastropoda, Naticoidea, Ampullinidae Age: Rupelian Stage (Stampian Stage), Lower Oligocene Locality: Gaas, Landes Department, Aquitaine, southwestern France
Permineralized Jurassic fern rhizome from Korsaröd (Sweden) of Osmundastrum pulchellum. It has preserved Nuclei and Chromosomes, a fine subcellular detail has rarely been documented in fossils. It´s Rooted in DNA content was used to extrapolate relative genome, finding relationships with extant Osmundastrum cinnamomeum, and confirmed a monophyletic Osmunda. Osmundastrum pulchellum is one of the earliest fossil Osmundastrum rhizomes known so far, and the first of its kind from the Mesozoic of Europe. Its impressive preservation has lead to know even the biotic interactions with the Plant. It also has recovered the only know case know to preserve the ongoing mitosis processes in plant cells via calcification from volcanic hydrothermal brine.
