géologie

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

Coelophysis bauri (Cope, 1887) theropod dinosaur from the Triassic of New Mexico, USA. This is a remarkable complete skeleton of the small early theropod Coelophysis. It comes from a nearly monospecific concentration of numerous complete to disarticulated skeletons in reddish-colored fluvial siltstones, often called a "Coelophysis graveyard". This occurrence has been interpreted as a carcass-jammed channel filling following mass mortality of dinosaurs by regional drought (see Schwartz & Gillette, 1994). Stratigraphy: Rock Point Member, Chinle Formation, Upper Triassic Locality: Whitaker Quarry (Coelophysis Quarry), Ghost Ranch, Rio Arriba County, northern New Mexico, USA Some info. from: Hunt, A.P. & S.G. Lucas. 1991. Rioarribasaurus, a new name for a Late Triassic dinosaur from New Mexico (USA). Paläontologische Zeitschrift 65: 191-198. Schwartz, H.L. & D.D. Gillette. 1994. Geology and taphonomy of the Coelophysis Quarry, Upper Triassic Chinle Formation, Ghost Ranch, New Mexico. Journal of Paleontology 68: 1118-1130. Theropod were small to large, bipedal dinosaurs. Almost all known members of the group were carnivorous (predators and/or scavengers). They represent the ancestral group to the birds, and some theropods are known to have had feathers. Some of the most well known dinosaurs to the general public are theropods, such as Tyrannosaurus, Allosaurus, and Spinosaurus.

Coelophysis bauri (Cope, 1887) theropod dinosaur from the Triassic of New Mexico, USA. This is a remarkable complete skeleton of the small early theropod Coelophysis. It comes from a nearly monospecific concentration of numerous complete to disarticulated skeletons in reddish-colored fluvial siltstones, often called a "Coelophysis graveyard". This occurrence has been interpreted as a carcass-jammed channel filling following mass mortality of dinosaurs by regional drought (see Schwartz & Gillette, 1994). Stratigraphy: Rock Point Member, Chinle Formation, Upper Triassic Locality: Whitaker Quarry (Coelophysis Quarry), Ghost Ranch, Rio Arriba County, northern New Mexico, USA Some info. from: Hunt, A.P. & S.G. Lucas. 1991. Rioarribasaurus, a new name for a Late Triassic dinosaur from New Mexico (USA). Paläontologische Zeitschrift 65: 191-198. Schwartz, H.L. & D.D. Gillette. 1994. Geology and taphonomy of the Coelophysis Quarry, Upper Triassic Chinle Formation, Ghost Ranch, New Mexico. Journal of Paleontology 68: 1118-1130. Theropod were small to large, bipedal dinosaurs. Almost all known members of the group were carnivorous (predators and/or scavengers). They represent the ancestral group to the birds, and some theropods are known to have had feathers. Some of the most well known dinosaurs to the general public are theropods, such as Tyrannosaurus, Allosaurus, and Spinosaurus.

Banded fine-grained pyrite in shale from the Precambrian of Australia. (public display, Leadville Mining Museum, Leadville, Colorado, USA) A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 4900 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates. The sulfide minerals contain one or more sulfide anions (S-2). The sulfides are usually considered together with the arsenide minerals, the sulfarsenide minerals, and the telluride minerals. Many sulfides are economically significant, as they occur commonly in ores. The metals that combine with S-2 are mainly Fe, Cu, Ni, Ag, etc. Most sulfides have a metallic luster, are moderately soft, and are noticeably heavy for their size. These minerals will not form in the presence of free oxygen. Under an oxygen-rich atmosphere, sulfide minerals tend to chemically weather to various oxide and hydroxide minerals. Pyrite is a common iron sulfide mineral (FeS2). It’s nickname is “fool's gold”. Pyrite has a metallic luster, brassy gold color (in contrast to the deep rich yellow gold color of true gold - www.flickr.com/photos/jsjgeology/sets/72157651325153769/), dark gray to black streak, is hard (H=6 to 6.5), has no cleavage, and is moderately heavy for its size. It often forms cubic crystals or pyritohedrons (crystals having pentagonal faces). Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits. The rock shown above consists of numerous bands of fine-grained pyrite interbedded with dark shale. Published research has shown that the pyrite is diagenetic, formed by sulfate reduction from sulfate-bearing groundwater that moved along bedding planes of the Urquhart Shale host rocks (see Painter et al., 1999). The sulfate source was evaporitic gypsum-anhydrite-barite in the same stratigraphic unit. Stratigraphy: Urquhart Shale, Mount Isa Group, Mesoproterozoic, ~1655 Ma Age of metamorphism: peak greenschist-facies metamorphism at ~1505 Ma during the Isan Orogeny Locality: Mount Isa Mines, northwestern Queensland, northeastern Australia Some info. from: Kawasaki & Symons (2010) - Dating of Mesoproterozoic metamorphism in the Mount Isa and George Fisher Zn-Pb-Cu-Ag deposits, Australia, by paleomagnetism. American Geophysical Union, Fall Meeting 2010, Abstract GP33C-0953. Painter et al. (1999) - Sedimentologic, petrographic, and sulfur isotope constraints on fine-grained pyrite formation at Mount Isa Mine and environs, northwest Queensland, Australia. Economic Geology 94: 883-912. Photo gallery of pyrite: www.mindat.org/gallery.php?min=3314

This image shows a 2.1 billion year old rock containing black-banded ironstone. The rock weighs about 8.5 tons, and is approximately two meters high, three meters wide, and one meter thick. It was found in North America and belongs to the National Museum of Mineralogy and Geology, Dresden, Germany. The rock is located at +51°2'34.84" +13°45'26.67".

Cast of a Scaphognathus crassirostris, a kind of pterosaur. On display as part of the exhibit "Pterosaurs: Flight in the Age of Dinosaurs" at the Cleveland Natural History Museum in Cleveland, Ohio, in the United States. This animal lived about 150 million years ago. This fossil was found in the Solnhofen formation in Germany. This is a cast; the fossil itself is held by the Institute of Geology and Paleontology at the University of Bonn.

Hadrocheilus aff. fragilis (Pictet & Loriol) Upper Valanginian, Komshitsa, Sofia Province, (Coll. G. Mandov) at the Sofia University 'St. Kliment Ohridski' Museum of Paleontology and Historical Geology

Hadrocheilus (Dentatobecus) gibber Till. Valanginian, Borima, Lovech Province, (Coll. G. Mandov) at the Sofia University 'St. Kliment Ohridski' Museum of Paleontology and Historical Geology

DUVALIA LATA (BLAINVILLE), VALANGINIAN, SELISHTE, GABROVO PROVINCE AT SOFIA UNIVERSITY 'ST. KLIMENT OHRIDSKI' MUSEUM OF PALEONTOLOGY AND HISTORICAL GEOLOGY

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.

A Specimen of Parapuzosia daubreei (de Grossouvre, 1894), Santonian, Shumen on display at Sofia University "St. Kliment Ohridski' Museum of Paleontology and Historical Geology

Eleniceras cf. curvicostatum (Tzankov), Lower Hauterivian, Kalotina, Bulgaria Cr1 963X1 at the Sofia University 'St. Kliment Ohriski' Museum of Paleontology and Historical Geology

Eleniceras aff. stevrecensis Breskovski, Lower Hauterivian, Dragoman, Bulgaria, Cr1 959 - Cr1 960 X 1 at the Sofia University 'St. Kliment Ohridski' Museum of Paleontology and Historical Geology