Results 51 to 60 of about 33,963 (268)

Functional anatomy, jaw mechanisms, and feeding behavior of Dunkleosteus terrelli (Placodermi, Arthrodira)

open access: yesThe Anatomical Record, EarlyView.
A new musculoskeletal reconstruction and revision of the cranio‐mandibular anatomy of the Devonian arthrodire placoderm Dunkleosteus terrelli from a comparative and functional anatomical perspective. Dunkleosteus is a specialized arthrodire with many specializations for feeding on large vertebrates, and many of its features are part of broader ...
Russell K. Engelman   +4 more
wiley   +1 more source

Diatoms (Bacillariophyceae) from the Valley of the Great Lakes in Western Mongolia [PDF]

open access: yesMongolian Journal of Biological Sciences, 2010
T he Valley of the Great Lakes (VOGL) in western Mongolia is dominated by two main (Uvs, Khyargas) and many minor closed basin lake systems. In 2004 and 2005, we sampled diatom communities from the surfi cial sediment of
Mark B. Edlund   +2 more
doaj   +1 more source

Skeletal pathologies in extant crocodilians as a window into the paleopathology of fossil archosaurs

open access: yesThe Anatomical Record, EarlyView.
Abstract Crocodilians, together with birds, are the only extant relatives to many extinct archosaur groups, making them highly important for interpreting paleopathological conditions in a phylogenetic disease bracketing model. Despite this, comprehensive data on osteopathologies in crocodilians remain scarce.
Alexis Cornille   +6 more
wiley   +1 more source

Testing the Tropical Niche Conservatism Hypothesis: Climatic Niche Evolution of Escallonia Mutis ex L. F. (Escalloniaceae)

open access: yesPlants
We assess the Tropical Niche Conservatism Hypothesis in the genus Escallonia in South America using phylogeny, paleoclimate estimation and current niche modelling.
María José Dibán   +1 more
doaj   +1 more source

Sharks, Rays and a Chimaeroid from the Kimmeridgian (Late Jurassic) of Ringstead, Southern England [PDF]

open access: yes, 2002
Sampling of a lenticular concentration of vertebrate debris and associated sediments from the lower Kimmeridgian of southern England has allowed the study of a diverse and abundant assemblage of chondrichthyan remains.
Underwood, Charlie J.
core   +1 more source

Comparative cranial biomechanics reveal macroevolutionary trends in theropod dinosaurs, with emphasis on Tyrannosauroidea

open access: yesThe Anatomical Record, EarlyView.
Abstract Tyrannosaurus is viewed as a model organism in vertebrate paleontology, with numerous studies analyzing its feeding biomechanics. Nonetheless, the evolution of this feeding performance has been under‐addressed in Tyrannosauroidea, especially in basal tyrannosauroids. Here we used muscle‐force reconstruction and finite element analysis (FEA) to
Evan Johnson‐Ransom   +4 more
wiley   +1 more source

Osteohistology of two phorusrhacids reveals uninterrupted growth strategy

open access: yesThe Anatomical Record, EarlyView.
Abstract Phorusrhacidae were apex predators that primarily dominated South America ecosystems for at least 40 million years with their imposing size and predatory lifestyle—yet some aspects of their biology remain poorly understood. Osteohistology is a tool for understanding growth dynamics and biomechanical adaptations.
Lotta Dreyer   +2 more
wiley   +1 more source

SEVERAL RESULTS OF BIOARCHAEOLOGICAL AND ETHNOECOLOGICAL INVESTIGATIONS IN TAJIKISTAN

open access: yesТеория и практика археологических исследований, 2022
The article describes several topics of joint Russian-Tajik research conducted since 2013 in the Khatlon velayat of the Republic of Tajikistan within the framework of the Memorandum of Cooperation between the N. N.
Н.А. Дубова   +5 more
doaj   +1 more source

Early evolutionary history of the seed

open access: yesBiological Reviews, EarlyView.
ABSTRACT The seed is an essential stage in the life history of gymnospermous and angiospermous plants, facilitating both their survival and dispersal. We reappraise knowledge of the evolutionary history of the gymnospermous seed, from its origin in the late Devonian through to the well‐known end‐Permian extinctions – an interval encompassing the ...
Richard M. Bateman   +2 more
wiley   +1 more source

Precise occlusion and trophic niche differentiation indicate specialized feeding in Early Devonian jawed vertebrates

open access: yesFACETS, 2017
Acanthodians may represent a paraphyletic assemblage of stem chondrichthyans, stem osteichthyans, stem gnathostomes, or some combination of the three. One of the difficulties in determining the phylogenetic affinities of this group of mostly small, spiny
Stephanie A. Blais
doaj   +1 more source

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