scholarly journals The Anatomy and Phylogenetic Relationships of “Pelorosaurus“ becklesii (Neosauropoda, Macronaria) from the Early Cretaceous of England

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0125819 ◽  
Author(s):  
Paul Upchurch ◽  
Philip D. Mannion ◽  
Michael P. Taylor
Keyword(s):  
Early Cretaceous ◽  
Phylogenetic Relationships

Cranial and post-cranial remains and phylogenetic relationships of the Gondwanan meiolaniform turtle Peligrochelys walshae from the Paleocene of Chubut, Argentina

2019 ◽  
Vol 93 (04) ◽  
pp. 798-821 ◽  
Author(s):  
Juliana Sterli ◽  
Marcelo S. de la Fuente
Keyword(s):  
Phylogenetic Analysis ◽  
3D Reconstruction ◽  
Early Cretaceous ◽  
Phylogenetic Relationships ◽  
Mass Extinction ◽  
Field Work ◽  
The Holocene ◽  
Previous Hypothesis ◽  
Postcranial Remains ◽  
Salamanca Formation

AbstractPeligrochelys walshae is a meiolaniform turtle originally described based on four specimens represented by cranial remains found in the classic locality of Punta Peligro (Chubut, Argentina) in outcrops of the Salamanca Formation (Danian). Recent field work in the vicinity of Punta Peligro resulted in the discovery of almost 30 new specimens, represented by cranial and postcranial remains that can be assigned to P. walshae. In this contribution, we provide a detailed anatomical description of the new specimens, provide an emended diagnosis for the species, and explore its phylogenetic relationships based on all anatomical data available for the species. The new specimens bring valuable information about the anatomy of the skull and postcranium of P. walshae as well as for meiolaniforms in general. The 3D preservation of the skull bones allows us to provide a 3D reconstruction using novel techniques. The updated phylogenetic analysis confirms that P. walshae is part of the clade Meiolaniformes, which spans from the Early Cretaceous until the Holocene and contains the giant, horned turtles (Meiolaniidae). This phylogenetic analysis reinforces the previous hypothesis that the clade Meiolaniformes is dominated by Gondwanan taxa, but also includes some Laurasian representatives. Alternate phylogenetic positions of taxa included in Meiolaniformes in this analysis were tested using the Templeton test. The lineage leading to Peligrochelys walshae is the only meiolaniform non-meiolaniid lineage to have survived the K-Pg mass extinction; its study provides valuable information to evaluate the effects of the K-Pg extinction in turtles.

scholarly journals The evolutionary history of polycotylid plesiosaurians

2018 ◽  
Vol 5 (3) ◽  
pp. 172177 ◽  
Author(s):  
V. Fischer ◽  
R. B. J. Benson ◽  
P. S. Druckenmiller ◽  
H. F. Ketchum ◽  
N. Bardet
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Neck Length ◽  
Ecological Release ◽  
Holotype Specimen ◽  
Low Diversity ◽  
History Of

Polycotylidae is a clade of plesiosaurians that appeared during the Early Cretaceous and became speciose and abundant early in the Late Cretaceous. However, this radiation is poorly understood. Thililua longicollis from the Middle Turonian of Morocco is an enigmatic taxon possessing an atypically long neck and, as originally reported, a series of unusual cranial features that cause unstable phylogenetic relationships for polycotylids. We reinterpret the holotype specimen of Thililua longicollis and clarify its cranial anatomy. Thililua longicollis possesses an extensive, foramina-bearing jugal, a premaxilla–parietal contact and carinated teeth. Phylogenetic analyses of a new cladistic dataset based on first-hand observation of most polycotylids recover Thililua and Mauriciosaurus as successive lineages at the base of the earliest Late Cretaceous polycotyline radiation. A new dataset summarizing the Bauplan of polycotylids reveals that their radiation produced an early burst of disparity during the Cenomanian–Turonian interval, with marked plasticity in relative neck length, but this did not arise as an ecological release following the extinction of ichthyosaurs and pliosaurids. This disparity vanished during and after the Turonian, which is consistent with a model of ‘early experimentation/late constraint’. Two polycotylid clades, Occultonectia clade nov. and Polycotylinae, survived up to the Maastrichtian, but with low diversity.

A Ceratopsian dinosaurPsittacosaurus sibiricusfrom the Early Cretaceous of West Siberia, Russia and its phylogenetic relationships

2006 ◽  
Vol 4 (4) ◽  
pp. 359-395 ◽  
Author(s):  
Alexander O. Averianov ◽  
Alexei V. Voronkevich ◽  
Sergei V. Leshchinskiy ◽  
Alexei V. Fayngertz
Keyword(s):  
Early Cretaceous ◽  
Phylogenetic Relationships ◽  
West Siberia

scholarly journals Rhinochelys amaberti Moret (1935), a protostegid turtle from the Early Cretaceous of France

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4594 ◽  
Author(s):  
Isaure Scavezzoni ◽  
Valentin Fischer
Keyword(s):  
Missing Data ◽  
Early Cretaceous ◽  
Phylogenetic Relationships ◽  
Sea Turtles ◽  
Phylogenetic Analyses ◽  
Marine Turtles ◽  
Valid Taxon

Modern marine turtles (chelonioids) are the remnants of an ancient radiation that roots in the Cretaceous. The oldest members of that radiation are first recorded from the Early Cretaceous and a series of species are known from the Albian-Cenomanian interval, many of which have been allocated to the widespread but poorly defined genus Rhinochelys, possibly concealing the diversity and the evolution of early marine turtles. In order to better understand the radiation of chelonioids, we redescribe the holotype and assess the taxonomy of Rhinochelys amaberti Moret (1935) (UJF-ID.11167) from the Late Albian (Stoliczkaia dispar Zone) of the Vallon de la Fauge (Isère, France). We also make preliminary assessments of the phylogenetic relationships of Chelonioidea using two updated datasets that widely sample Cretaceous taxa, especially Rhinochelys. Rhinochelys amaberti is a valid taxon that is supported by eight autapomorphies; an emended diagnosisis proposed. Our phylogenetic analyses suggest that Rhinochelys could be polyphyletic, but constraining it as a monophyletic entity does not produce trees that are significantly less parsimonious. Moreover, support values and stratigraphic congruence indexes are fairly low for the recovered typologies, suggesting that missing data still strongly affect our understanding of the Cretaceous diversification of sea turtles.

Whole-Plant Reconstruction and Phylogenetic Relationships of Elatides zhoui sp. nov. (Cupressaceae) from the Early Cretaceous of Mongolia

2014 ◽  
Vol 175 (8) ◽  
pp. 911-930 ◽  
Author(s):  
Gongle Shi ◽  
Andrew B. Leslie ◽  
Patrick S. Herendeen ◽  
Niiden Ichinnorov ◽  
Masamichi Takahashi ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Phylogenetic Relationships ◽  
Whole Plant

Architecture of Radiolitid Rudist (Mollusca) Shell-Wall Structures and its Phylogenetic Implications

1975 ◽  
Vol 33 ◽  
pp. 686-687
Author(s):  
David H. Sturm ◽  
Bob F. Perkins
Keyword(s):  
Phylogenetic Relationships ◽  
Outer Wall ◽  
Shell Microstructure ◽  
Shell Wall ◽  
Wall Structures ◽  
Phylogenetic Implications ◽  
Cellular Wall ◽  
Superfamily Analysis ◽  
Central Texas

Each of the seven families of rudists (Mollusca, Bivalvia, Hippuritacea) is characterized by distinctive shell-wall architectures which reflect phylogenetic relationships within the superfamily. Analysis of the complex, calcareous, cellular wall of the attached valve of the radiolite rudist Eoradiolites davidsoni (Hill) from the Comanche Cretaceous of Central Texas indicates that its wall architecture is an elaboration of the simpler monopleurid rudist wall and supports possible radiolite-monopleurid relationships.Several well-preserved specimens of E. davidsoni were sectioned, polished, etched, and carbon and gold coated for SEM examination. Maximum shell microstructure detail was displayed by etching with a 0.7% HC1 solution from 80 to 100 seconds.The shell of E. davidsoni comprises a large, thick-walled, conical, attached valve (AV) and a small, very thin, operculate, free valve (FV) (Fig. 1a). The AV shell is two-layered with a thin inner wall, in which original structures are usually obliterated by recrystallization, and a thick, cellular, outer wall.

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