Results 21 to 30 of about 496 (122)

Upper Cretaceous European theropod palaeobiodiversity, palaeobiogeography and the intra‐Maastrichtian faunal turnover: new contributions from the Iberian fossil site of Laño

open access: yesPapers in Palaeontology, Volume 8, Issue 1, January/February 2022., 2022
Abstract A total of 227 theropod teeth have so far been recovered from the upper Campanian Laño site (northern Iberian Peninsula). The teeth were studied for their qualitative and quantitative features. From the theropod sample found at Laño, seven morphotypes attributed to five taxa are identified: a medium to large abelisaurid (Arcovenator sp.) and ...
Erik Isasmendi   +5 more
wiley   +1 more source

The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents [PDF]

open access: yesPeerJ, 2016
Background: Powered flight is implicated as a major driver for the success of birds. Here we examine the effectiveness of three hypothesized pathways for the evolution of the flight stroke, the forelimb motion that powers aerial locomotion, in a ...
T. Alexander Dececchi   +2 more
doaj   +2 more sources

The asymmetry of the carpal joint and the evolution of wing folding in maniraptoran theropod dinosaurs [PDF]

open access: yesProceedings of the Royal Society B: Biological Sciences, 2010
Corwin Sullivan   +2 more
exaly   +2 more sources

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

Osteology of the unenlagiid theropod Neuquenraptor argentinus from the Late Cretaceous of Patagonia [PDF]

open access: yes, 2017
Neuquenraptor argentinus was described as the first undoubted deinonychosaurian theropod from Gondwana. The only known specimen is represented by a fragmentary skeleton, including a nearly complete foot, coming from Late Cretaceous beds of Neuquén ...
Agnolin, Federico   +3 more
core   +2 more sources

Descendants of the Jurassic turiasaurs from Iberia found refuge in the Early Cretaceous of western USA [PDF]

open access: yes, 2017
A new, largely complete eusauropod dinosaur with cranial and postcranial elements from two skeletons, Mierasaurus bobyoungi gen. nov., sp. nov. from the lower Yellow Cat Member (Early Cretaceous) of Utah (USA), is the first recognized member of ...
Alcalá, L   +6 more
core   +2 more sources

Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds

open access: yesGeosciences, 2012
At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the ...
David J. Bottjer   +4 more
doaj   +1 more source

A New Specimen of Autroraptor cabazai Novas, Pol. Canale, Porfiri and Calvo, 2008 (Dinosauria, Theropoda, Unenlagiidae) from the Latest Cretaceous (Maastrichtian) of Río Negro, Argentina [PDF]

open access: yes, 2012
There were considerable differences in Late Cretaceous faunas of the Northern and Southern Hemispheres, although the differences were breaking down during Campanian and Maastrichtian times with the appearance of hadrosaurids in Antarctica and South ...
Currie, Philip J.   +1 more
core   +1 more source

Unique caudal plumage of Jeholornis and complex tail evolution in early birds [PDF]

open access: yes, 2013
The Early Cretaceous bird Jeholornis was previously only known to have a distally restricted ornamental frond of tail feathers. We describe a previously unrecognized fan-shaped tract of feathers situated dorsal to the proximal caudal vertebrae.
O'Connor, Jingmai   +6 more
core   +2 more sources

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