Results 51 to 60 of about 1,927,269 (224)

Type Crania of the Devonian Placoderm Macropetalichthys from North America: Resolving Key Nomenclatural and Stratigraphic Conundrums

open access: yesFishes
Macropetalichthys rapheidolabis Norwood and Owen, 1846 (Placodermi: Petalichthyida), type species of Macropetalichthys Norwood and Owen, 1846, was based on a single cranial roof from the Devonian of southeastern Indiana.
Loren E. Babcock
doaj   +1 more source

Devonian stratigraphy in Estonia: current state and problems [PDF]

open access: yesEstonian Journal of Earth Sciences, 2012
An updated version of the Devonian stratigraphical chart of Estonia with comments is presented. Estonian regional stratigraphical units are correlated with the standard conodont zonation and miospore zonation, used in the western part of the East ...
Elga Mark-Kurik, Anne Põldvere
doaj   +1 more source

Cortical bone geometry and static gravitational loads in neosauropod dinosaurs: Implications for biomechanical constraints on terrestrial gigantism

open access: yesThe Anatomical Record, EarlyView.
Abstract Sauropod dinosaurs achieved unprecedented terrestrial gigantism, raising questions about the biomechanical limits of bone under extreme gravitational loads. We estimated static gravitational pressures (Pg) on appendicular cortical bone in neosauropods, including diplodocoids, brachiosaurids, and titanosaurs.
Tito Aureliano   +4 more
wiley   +1 more source

The life and work of Ernest Sydney Keeping

open access: yesCanadian Journal of Statistics, EarlyView.
Abstract This article reviews the life and contributions of Ernest S. Keeping (1895–1984), a British‐born physicist who became a mathematics professor at the University of Alberta in 1929. He played a pivotal role in shaping the university's Mathematics Department, serving as its head from 1954 to 1961, and continuing to teach until 1970, nine years ...
David R. Bellhouse, Christian Genest
wiley   +1 more source

Givetian (Middle Devonian) cladoxylopsid 'ferns' from Orkney, northern Scotland [PDF]

open access: yes, 2006
Two large fossil plants are described from the Givetian (Middle Devonian) Eday Flags, South Ronaldsay, Orkney Isles, northern Scotland. Fossils with branches joined to stems of this age are rare.
Berry, Christopher Mark   +3 more
core   +1 more source

Orthodentine‐osteodentine and osteocytic‐anosteocytic transition inferred from Silurian stem chondrichthyan dermal jawbones with ever‐white teeth overgrown by brown denticles

open access: yesDevelopmental Dynamics, EarlyView.
Abstract Background The dentigerous jawbones of a 423‐million‐year‐old stem chondrichthyan (ischnacanthid acanthodian) carry a characteristic combination of multi‐row non‐shedding white teeth with brownish overgrowing denticles. The color distinction makes it a good model for observing the interaction between two odontode lineages, but the nature of ...
Jia‐Cih Kang   +3 more
wiley   +1 more source

The Economic Geology of The Iowa Devonian [PDF]

open access: yes, 1970
The Devonian System, in Iowa, is exposed in a belt about 50 miles wide extending along a line from Mason City to Muscatine. With the exception of the Shell Rock Formation the Upper Devonian is essentially elastic, dominantly shale. The Middle Devonian is
Dorheim, Fred H.
core   +1 more source

Geochemistry and Geochronology of Magmatic Rocks in Southwestern and Northeastern Cambodia: Implications for the Tectonic Evolution and Metallogenesis of the Loei Fold Belt

open access: yesGeological Journal, EarlyView.
The composition of intrusive rocks suggests that the magma was likely generated in a subduction‐related setting. The arc crustal thickness in the Phnom Sro Ngam and Halo Prospects was probably < 40 km during emplacement. Zircon U–Pb age range indicates a correlation with Loei Fold Belt magmatic activity.
Sirisokha Seang   +6 more
wiley   +1 more source

Bryozoan‐Rich Carbonate Units of the Erfoud Area (SE Morocco) Record Latest Katian to Early Hirnantian Interglacial Intervals

open access: yesGeological Journal, EarlyView.
In this study, we re‐examine the depositional architecture of the Erfoud limestone in Morocco. Introducing new biostratigraphic constraints from chitinozoan assemblages, we show that Katian to Hirnantian bryozoan‐pelmatozoan meadows reflect flooding events linked to a series of interglacial transgressions known to have occurred immediately prior to the
Philippe Razin   +4 more
wiley   +1 more source

Reservoir characterization and potential of the old red sandstone around the inner moray firth, NE Scotland [PDF]

open access: yes, 1993
Old Red Sandstone deposition in North East Scotland occurred during Devonian times within the Orcadian Basin, a northeast-southwest elongated structure. The basin formed in an extensional tectonic regime that resulted from gravitational collapse of over ...
Forbes, Douglas
core  

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