Results 241 to 250 of about 63,232 (285)

Ecological patterns in middle Jurassic

2005
Gryphaea is a typical oyster, sensitive and reactive to the environment and thus variable in aspects of form, such as the size of the attachment area. Nevertheless, there are regular relationships between form and specific properties of the environment, at both the intra- and inter-specific levels and for various stratigraphic horizons throughout the ...
Ulf Bayer, Andrew L. A. Johnson, Joseph Brannan   +2 more
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A Middle Jurassic mammal from Madagascar

Nature, 1999
The lower molars of tribosphenic mammals (marsupials, placentals and their extinct allies) are marked, primitively, by a basined heel (talonid) acting as the mortar to the pestle of a large inner cusp (protocone) on the opposing upper teeth. Here we report the earliest tribosphenic mammal found so far, three lower teeth in a jaw fragment from Middle ...
John J. Flynn, J. Michael Parrish, Berthe Rakotosamimanana, William F. Simpson, André R. Wyss   +4 more
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Jurassic faunas of the Canadian Arctic, Lower Jurassic and lowermost Middle Jurassic ammonites

1960
Lower Jurassic and lower Bajocian faunas are widely distributed in the Canadian Arctic, particularly in the Arctic Archipelago, where marine lower Sinemurian, Toarcian, and Bajocian are represented. In the Aklavik Range (northeastern Richardson Mountains, Arctic Coast region) lower and upper Sinemurian rocks are present; farther to the west lower ...
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Harvestmen (Arachnida: Opiliones) from the Middle Jurassic of China

Naturwissenschaften, 2009
Harvestmen (Arachnida: Opiliones) are familiar animals in most terrestrial habitats but are rare as fossils, with only a handful of species known from each of the Palaeozoic, Mesozoic, and Cenozoic eras. Fossil harvestmen from Middle Jurassic (ca. 165 Ma) strata of Daohugou, Inner Mongolia, China, are described as Mesobunus martensi gen. et sp.
Diying, Huang, Paul A, Selden, Jason A, Dunlop   +2 more
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Middle Jurassic inoceramids from Argentina

Journal of Paleontology, 1990
Extensive collections from stratigraphically controlled sections allow reassessment and systematic revision of Middle Jurassic inoceramids from Argentina. Two species are doubtfully referred toParainoceramusVoronetz, includingP.?westermannin. sp. Five species ofRetroceramusKoshelkina, includingR.cf.R. marwicki(Speden),R.
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The Jurassic faunas of the Canadian Arctic, middle and upper Jurassic, ammonites

1961
Middle and Upper Jurassic faunas have a wide distribution in the Canadian Arctic. The following index ammonites indicate the presence of various stages: Leioceras opa/inum, Pseudolioceras m'c/intocki (see Frebold, 1960) , and Erycites cf. E. howelli (lower Bajocian) ; Cranocephalites borealis and C. warreni n. sp.
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Outgrowths on Zircon in the Middle Jurassic of Yorkshire

Geological Magazine, 1937
In view of Mr. J. A. Butterfield's account of outgrowths on zircon in the Millstone Grit of the Pennine region (Geol. Mag., LXXIII, 1936, 511–16), it may be of interest to record the occurrence of similar grains in the Middle Jurassic sandstones of Yorkshire.
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Middle Jurassic with Selliporella donzellii

2007
Algal remnants, that occur only rarely in the lower part of the Biokovo road, become more frequent and abundant as we go higher through the succession. The maximum concentration of the algal skeletons or skeletal fragments, mostly of Selliporella donzellii SARTONI & CRESCENTI, occur within individual beds or thinner intervals of successive layers in ...
Sokač, Branko, Velić, Ivo
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Iterative evolution of Middle Jurassic ammonite faunas

Lethaia, 1984
The phenomenon of iterative evolution of homeomorphs in identical temporal sequences is exhibited by Aalenian and Bajocian ammonite faunas in the south German depositional basin. Within each evolutionary cycle, inflated, evolute, and ornamented shells with complex suture lines are successively replaced with discoidal, involute, smooth shells with ...
Ulf Bayer, George R. McGhee
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Glossopterid Leaves from the Middle Jurassic of Oaxaca, Mexico

Science, 1969
Leaves indistinguishable from those of the late Paleozoic genus Glossopteris occur in Middle Jurassic beds in the State of Oaxaca, Mexico. If they are biologically related to the Permo-Carboniferous Glossopteris, the occurrence in Mexico is the latest report of the genus.
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