Jurassique

Figure 1: Reconstruction of the skull of Bellusaurus sui from the Middle-Late Jurassic Shishugou Formation of Xinjiang, China. This reconstruction is a composite based on isolated holotypic and referred material. (A) Right lateral view. (B) Dorsal view. Holotypic elements are indicated in blue and referred elements are in green.

Aalenian GSSP (Lower-Middle Jurassic boundary). Golden spike ceremony: July, 28th 2016. Fuentelsaz, Guadalajara, Spain

Laurasia during the closure of the Iapetus Ocean at 430 Ma. Made using GPlates: Citations: Golonka, J. (2007), Late Triassic and Early Jurassic palaeogeography of the world, Palaeogeography, Palaeoclimatology, Palaeoecology, 244(1-4), 297-307. Müller, R., M. Sdrolias, C. Gaina, and W. Roest (2008), Age, spreading rates, and spreading asymmetry of the world's ocean crust, Geochemistry, Geophysics, Geosystems, 9(Q04006), 19. Seton, M., R. Müller, S. Zahirovic, C. Gaina, T. Torsvik, G. Shephard, A. Talsma, M. Gurnis, M. Turner, and M. Chandler (2012), Global continental and ocean basin reconstructions since 200 Ma, Earth-Science Reviews, 113(3-4), 212-270. Torsvik, T., and R. Van de Voo (2002), Refining Gondwana and Pangea Palaeogeography: Estimates of Phanerozoic non dipole (octupole) fields, Geophysical Journal International, 151(3), 771-794. Wright, N., S. Zahirovic, R. D. Müller, and M. Seton (2013), Towards community-driven, open-access paleogeographic reconstructions: integrating open-access paleogeographic and paleobiology data with plate tectonics, Biogeosciences, 10, 1529-1541

Laurasia during the closure of the Iapetus Ocean at 430 Ma. Made using GPlates: Citations: Golonka, J. (2007), Late Triassic and Early Jurassic palaeogeography of the world, Palaeogeography, Palaeoclimatology, Palaeoecology, 244(1-4), 297-307. Müller, R., M. Sdrolias, C. Gaina, and W. Roest (2008), Age, spreading rates, and spreading asymmetry of the world's ocean crust, Geochemistry, Geophysics, Geosystems, 9(Q04006), 19. Seton, M., R. Müller, S. Zahirovic, C. Gaina, T. Torsvik, G. Shephard, A. Talsma, M. Gurnis, M. Turner, and M. Chandler (2012), Global continental and ocean basin reconstructions since 200 Ma, Earth-Science Reviews, 113(3-4), 212-270. Torsvik, T., and R. Van de Voo (2002), Refining Gondwana and Pangea Palaeogeography: Estimates of Phanerozoic non dipole (octupole) fields, Geophysical Journal International, 151(3), 771-794. Wright, N., S. Zahirovic, R. D. Müller, and M. Seton (2013), Towards community-driven, open-access paleogeographic reconstructions: integrating open-access paleogeographic and paleobiology data with plate tectonics, Biogeosciences, 10, 1529-1541

Original figure caption: .mw-parser-output .smallcaps{font-variant:small-caps}The Middletown Slab covered with the Footprints of Carnivorous Dinosaurs. The tracks are in high relief. Additional notes: Most if not all of these tridactylous (i.e. three-toed) footprints/tracks (but not the actual trackmaker!) are referred to as Grallator or as Grallator-type trace fossils. “High relief” means that these are actually casts of footprints forming a positive relief on the lower surface of the sandstone slab (so-called positive hyporelief). The material that originally formed the mud over which the dinosaurs walked was too friable to be recovered from the quarry in one piece. The slab consists of so called ‘brownstone’ which is the trading name of the sandstone quarried at Middletown, Connecticut. This sandstone belongs to the Lower Jurassic Portland Formation of the Hartford Basin (“Connecticut Valley”) and thus to the upper part of the Newark Supergroup. The trackmakers probably were relatively small ‘primitive’ theropod dinosaurs (coelophysoids) such as Podokesaurus the remains of which were recovered from Lower Jurassic deposits of the Hartford Basin.

Eubrontes dinosaur track from the Jurassic of Connecticut, USA. Trace fossils are any indirect evidence of ancient life. They refer to features in rocks that do not represent parts of the body of a once-living organism. Traces include footprints, tracks, trails, burrows, borings, and bitemarks. Body fossils provide information about the morphology of ancient organisms, while trace fossils provide information about the behavior of ancient life forms. Interpreting trace fossils and determination of the identity of a trace maker can be straightforward (for example, a dinosaur footprint represents walking behavior) or not. Sediments that have trace fossils are said to be bioturbated. Burrowed textures in sedimentary rocks are referred to as bioturbation. Trace fossils have scientific names assigned to them, in the same style & manner as living organisms or body fossils. This track was made by a theropod, a group of small to large, carnivorous, bipedal dinosaurs. The specimen comes from a Triassic to Jurassic terrestrial sedimentary succession that filled up a half graben, many of which occur along America's eastern seaboard. Such half-graben basins formed during the Triassic as the Pangaea supercontinent tried to rift apart, but failed. Pangaea successfully broke apart during the Jurassic. Stratigraphy: East Berlin Formation, Newark Supergroup, Lower Jurassic Locality: unrecorded / undisclosed site at or near the town of Rocky Hill, central Connecticut, USA Info. at: mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=CTJeb%3B0 and en.wikipedia.org/wiki/Eubrontes

The type specimen of the ichnogenus Cheliceratichnus, from the Early Jurassic East Berlin Formation of Holyoke, Massachusetts.

Bifurculapes laqueatus trackway (positive hyporelief, i.e. casts on the bottom surface of the bed) from the Early Jurassic East Berlin Formation (Hartford Basin) of Holyoke, Massachusetts (not the same specimen as this one). See coin (1 U.S. cent, 19.05 mm in diameter) for scale.

Bifurculapes laqueatus trackway (positive hyporelief, i.e. casts on the bottom surface of the bed) from the Early Jurassic East Berlin Formation (Hartford Basin) of Holyoke, Massachusetts (not the same specimen as this one). See coin (1 U.S. cent, 19.05 mm in diameter) for scale.

A trackway of the trace fossil Bifurculapes laqueatus (positive hyporelief, i.e. casts on the bottom surface of the bed) from the Early Jurassic East Berlin Formation (Hartford Basin) of Holyoke, Massachusetts (not the same specimen as this one). Scale is in cm.

Morrison Formation (lower half), Jurassic-Cretacous boundary (K1 Unconformity) at red and orange paleosol, Cedar Mountain Formation (drab gray), and capping Naturita Formation. West of Dinosaur National Monument.

Paleogeography and paleoclimate of the Late Jurassic - 150 Ma with dinosaur fossil localities: A = Tendaguru Formation, Tanzania C1 = Shishugou & Kalazha Formations, China C2 = Shangshaximiao (Upper Shaximiao) Formation, China E1 = Sables de Glos, Argiles d’Octeville, Marnes de Bléville, Kimmeridge Clay, Calcareous Grit, Corallian Oolite, Oxford Clay, Portland Stone, England & France E2 = Villar del Arzobispo, Alcobaça, Guimarota, Sobral, Amoreira-Porto Novo, Bombarral, Freixial, Lourinhã Formations, Spain & Portugal M1-6 = Morrison Formation, United States S1 = Toquí & Cañadón Calcáreo Formations, Chile & Argentina

San Rafael Reef, Utah, looking north from near I-70. The prominent white ridge is Jurassic Navajo Sandstone that has been warped upwards.

Oxford Clay (Jurassic) exposed near Weymouth, England.

Bituminous claystone, Lower Jurassic, Hesselberg, Middle Franconia. Sedimentary rock of very thin laminated layers (particles less than 0,0002 mm). Rock formation is known for its rich fossil findings, ex. Ichthyosaur.

Oxfordian (Upper Jurassic) cyclic sediments at Péry-Reuchenette, near Tavannes, kanton Bern, Switzerland. Alternating layers are limestone (light, more competent) and marl/clay; dominant cycle is the 200.000 year-cycle.