Results 61 to 70 of about 12,664 (238)

New craniodental materials of Falcarius utahensis (Theropoda: Therizinosauria) reveal patterns of intraspecific variation and cranial evolution in early coelurosaurians

open access: yesThe Anatomical Record, EarlyView.
Abstract Despite documented ecomorphological shifts toward an herbivorous diet in several coelurosaurian lineages, the evolutionary tempo and mode of these changes remain poorly understood, hampered by sparse cranial materials for early representatives of major clades. This is particularly true for Therizinosauria, with representative crania best known
William J. Freimuth, Lindsay E. Zanno
wiley   +1 more source

The coelurosaur theropods of the Romualdo formation, early Cretaceous (Aptian) of Brazil: Santanaraptor placidus meets Mirischia asymmetrica

open access: yesThe Anatomical Record, EarlyView.
Abstract The upper carbonate concretion levels of the Romualdo Formation (Aptian, Brazil) have yielded several theropod dinosaur remains, including spinosaurids and the coelurosaurs Santanaraptor placidus and Mirischia asymmetrica, the phylogenetic affinities of which are controversial.
Rafael Delcourt   +4 more
wiley   +1 more source

The onset of grasses in the Amazon drainage basin, evidence from the fossil record [PDF]

open access: yes, 2020
Poaceae (the grass family) originated in the Cretaceous, but first dominate the palynological records of the Amazon drainage basin (ADB) in the Neogene (23 to 2.5 million years ago (Ma)).
Hoorn, Carina, Kirschner, Judith A.
core   +3 more sources

Re‐evaluation of a soft crested Edmontosaurin, with implications for hadrosaurid life appearance and diversity

open access: yesThe Anatomical Record, EarlyView.
Abstract Hadrosaurid dinosaurs are generally regarded as “crested” or “non‐crested” depending on the presence or absence of a bony cranial crest. At least one supposedly “non‐crested” hadrosaur is known to have possessed a soft tissue cranial crest (or comb), based on an exceptionally preserved “mummified” specimen. Here we redescribe this specimen and
Henry S. Sharpe   +4 more
wiley   +1 more source

Dinosaur ichnology and sedimentology of the Chignik Formation (Upper Cretaceous), Aniakchak National Monument, southwestern Alaska; Further insights on habitat preferences of high-latitude hadrosaurs.

open access: yesPLoS ONE, 2019
While there are now numerous records of dinosaurs from Cretaceous rocks around the state of Alaska, very few fossil records of terrestrial vertebrates are known from the Mesozoic rocks of the southwestern part of the state.
Anthony R Fiorillo   +7 more
doaj   +1 more source

Mid-mantle deformation inferred from seismic anisotropy [PDF]

open access: yes, 2002
With time, convective processes in the Earth's mantle will tend to align crystals, grains and inclusions. This mantle fabric is detectable seismologically, as it produces an anisotropy in material properties—in particular, a directional dependence in ...
A Yeganeh-Haeri   +34 more
core   +4 more sources

Growth dynamics, skeletochronology, and histovariability of the theropod dinosaur Berthasaura leopoldinae

open access: yesThe Anatomical Record, EarlyView.
Osteohistological sampling on different bones of theropod dinosaur documents discrepant age record, growth, and metabolism. This could result unprecise paleobiological inferences if samplings are based on single bones. However, multi‐bone sampling can attenuate these discrepancies, helping to infer growth dynamics and physiology of these extinct ...
Geovane Alves de Souza   +3 more
wiley   +1 more source

Platinum Group Element Traces of CAMP Volcanism Associated With Low‐Latitude Environmental and Biological Disruptions

open access: yesGeophysical Monograph Series, Page 263-304., 2021

Exploring the links between Large Igneous Provinces and dramatic environmental impact

An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Jessica H. Whiteside   +3 more
wiley  

+1 more source

Nothing Besides Remains: Preserving the Scientific and Cultural Value of Paleontological Resources in the United States [PDF]

open access: yes, 2005
Receptor occupancy assessed by Positron Emission Tomography (PET) can provide important translational information to help bridge information from one drug to another or from animal to man.
Chew, Alexa Z.
core   +1 more source

Endothermy, neuron counts, and other issues: Further remarks on neurocognitive evolution in fossil vertebrates

open access: yesThe Anatomical Record, EarlyView.
Abstract Last year, we challenged the view that large‐bodied theropod dinosaurs such as Tyrannosaurus rex resembled primates in cognition and behavior, a proposition made by Herculano‐Houzel in 2023. More recently, Jensen et al. have criticized our work on this topic, raising methodological and conceptual issues.
Kai R. Caspar   +5 more
wiley   +1 more source

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