Osteology of the Late Jurassic Portuguese sauropod dinosaurLusotitan atalaiensis(Macronaria) and the evolutionary history of basal titanosauriforms

2013 ◽  
Vol 168 (1) ◽  
pp. 98-206 ◽  
Author(s):  
Philip D. Mannion ◽  
Paul Upchurch ◽  
Rosie N. Barnes ◽  
Octávio Mateus
Keyword(s):  
Late Jurassic ◽  
Evolutionary History ◽  
History Of

scholarly journals A new stem turtle from the Middle Jurassic of Scotland: new insights into the evolution and palaeoecology of basal turtles

2008 ◽  
Vol 276 (1658) ◽  
pp. 879-886 ◽  
Author(s):  
Jérémy Anquetin ◽  
Paul M Barrett ◽  
Marc E.H Jones ◽  
Scott Moore-Fay ◽  
Susan E Evans
Keyword(s):  
Middle Jurassic ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Sister Group ◽  
Late Triassic ◽  
Sister Group Relationship ◽  
New Taxon ◽  
Crown Group ◽  
History Of ◽  
Isle Of Skye

The discovery of a new stem turtle from the Middle Jurassic (Bathonian) deposits of the Isle of Skye, Scotland, sheds new light on the early evolutionary history of Testudinata. Eileanchelys waldmani gen. et sp. nov. is known from cranial and postcranial material of several individuals and represents the most complete Middle Jurassic turtle described to date, bridging the morphological gap between basal turtles from the Late Triassic–Early Jurassic and crown-group turtles that diversify during the Late Jurassic. A phylogenetic analysis places the new taxon within the stem group of Testudines (crown-group turtles) and suggests a sister-group relationship between E. waldmani and Heckerochelys romani from the Middle Jurassic of Russia. Moreover, E. waldmani also demonstrates that stem turtles were ecologically diverse, as it may represent the earliest known aquatic turtle.

scholarly journals The first definitive Middle Jurassic atoposaurid (Crocodylomorpha, Neosuchia), and a discussion on the genus Theriosuchus

2017 ◽  
Author(s):  
Mark T. Young ◽  
Jonathan Tennant ◽  
Stephen L. Brusatte ◽  
Thomas J. Challands ◽  
Nicholas C. Fraser ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Valid Species ◽  
Diagnostic Features ◽  
Comprehensive Review ◽  
History Of ◽  
Isle Of Skye ◽  
Broad Scale

Atoposaurids were a clade of semiaquatic crocodyliforms known from the Late Jurassic to the latest Cretaceous. Tentative remains from Europe, Morocco, and Madagascar may extend their range into the Middle Jurassic. Here we report the first unambiguous Middle Jurassic (late Bajocian–Bathonian) atoposaurid: an anterior dentary from the Isle of Skye, Scotland, UK. A comprehensive review of atoposaurid specimens demonstrates that this dentary can be referred to Theriosuchus based on several derived characters, and differs from the five previously recognized species within this genus. Despite several diagnostic features, we conservatively refer it to Theriosuchus sp., pending the discovery of more complete material. As the oldest known definitively diagnostic atoposaurid, this discovery indicates that the oldest members of this group were small-bodied, had heterodont dentition, and were most likely widespread components of European faunas. Our review of mandibular and dental features in atoposaurids not only allows us to present a revised diagnosis of Theriosuchus, but also reveals a great amount of variability within this genus, and indicates that there are currently five valid species that can be differentiated by unique combinations of dental characteristics. This variability can be included in future broad-scale cladistics analyses of atoposaurids and closely related crocodyliforms, which promise to help untangle the complicated taxonomy and evolutionary history of Atoposauridae.

scholarly journals Osteology of Klamelisaurus gobiensis (Dinosauria, Eusauropoda) and the evolutionary history of Middle–Late Jurassic Chinese sauropods

2020 ◽  
Vol 18 (16) ◽  
pp. 1299-1393 ◽  
Author(s):  
Andrew J. Moore ◽  
Paul Upchurch ◽  
Paul M. Barrett ◽  
James M. Clark ◽  
Xu Xing
Keyword(s):  
Late Jurassic ◽  
Evolutionary History ◽  
History Of

The skeletal morphology of the solemydid turtleNaomichelys speciosafrom the Early Cretaceous of Texas

2014 ◽  
Vol 88 (6) ◽  
pp. 1257-1287 ◽  
Author(s):  
Walter G. Joyce ◽  
Juliana Sterli ◽  
Sandra D. Chapman
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Posterior Margin ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Ventral View ◽  
Skeletal Morphology ◽  
History Of

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian–Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred toNaomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian–Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnoseNaomichelys speciosaas a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguishNaomichelys speciosafrom the near-coeval European taxonHelochelydra nopcsai.

scholarly journals A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs

2013 ◽  
Vol 9 (4) ◽  
pp. 20130021 ◽  
Author(s):  
Valentin Fischer ◽  
Robert M. Appleby ◽  
Darren Naish ◽  
Jeff Liston ◽  
James B. Riding ◽  
...  
Keyword(s):  
Middle East ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Early Jurassic ◽  
Late Triassic ◽  
Low Diversity ◽  
History Of

Cretaceous ichthyosaurs have typically been considered a small, homogeneous assemblage sharing a common Late Jurassic ancestor. Their low diversity and disparity have been interpreted as indicative of a decline leading to their Cenomanian extinction. We describe the first post-Triassic ichthyosaur from the Middle East, Malawania anachronus gen. et sp. nov. from the Early Cretaceous of Iraq, and re-evaluate the evolutionary history of parvipelvian ichthyosaurs via phylogenetic and cladogenesis rate analyses. Malawania represents a basal grade in thunnosaurian evolution that arose during a major Late Triassic radiation event and was previously thought to have gone extinct during the Early Jurassic. Its pectoral morphology appears surprisingly archaic, retaining a forefin architecture similar to that of its Early Jurassic relatives. After the initial latest Triassic radiation of early thunnosaurians, two subsequent large radiations produced lineages with Cretaceous representatives, but the radiation events themselves are pre-Cretaceous. Cretaceous ichthyosaurs therefore include distantly related lineages, with contrasting evolutionary histories, and appear more diverse and disparate than previously supposed.

scholarly journals The complicated and surprisingly early origin of the pterodactyloid bauplan

2017 ◽  
Author(s):  
David M. Unwin
Keyword(s):  
Phylogenetic Analysis ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Upper Jurassic ◽  
Anatomical Changes ◽  
History Of ◽  
Fifth Toe ◽  
Early Origin ◽  
Early Late ◽  
Complex Evolutionary History

The origin of the pterodactyloid bauplan from that of non-monofenestratan (‘rhamphorhynchoid’) pterosaurs involved extensive anatomical changes and had profound consequences for the evolutionary history of Pterodactyloidea, a clade that dominated the aerial realm throughout the Cretaceous. This important evolutionary transformation, about which almost nothing was known for almost two centuries, is now rapidly coming into focus thanks to a plethora of new pterosaur fossils from the Middle and Upper Jurassic of South America, Europe and China. So far, however, these finds have largely been considered in isolation from each other and few have been thoroughly evaluated. Phylogenetic analysis, combined with improved stratigraphic data for all potentially relevant taxa including putative non-pterodactyloid monofenstratans (NPMs) and the oldest known pterodactyloids (e.g. Liaodactylus) was used to generate a new map of the anatomical transformations and temporal history of the non-monofenestratan–pterodactyloid transition. Evolution of the pterodactyloid skull construction predates the Middle Jurassic, but remains almost completely undocumented by fossils. Liaodactylus reveals that innovation in pterodactyloid skull anatomy and the appearance of derived features was well underway prior to the Upper Jurassic. Douzhanopterus, a derived NPM, demonstrates that elongation of the metacarpus and reduction of the tail and fifth toe (classic pterodactyloid synapomorphies) also predates the Upper Jurassic, but disjunction in the degree of their development across taxa is not consistent with simple explanations such as ‘adaptation for flight’. Overall, late Early to early Late Jurassic pterosaurs were much more diverse and had a far more complex evolutionary history than heretofore recognised.

scholarly journals A new stem turtle from the Middle Jurassic of Scotland: new insights into the evolution and palaeoecology of basal turtles

2017 ◽  
Author(s):  
Jérémy Anquetin ◽  
Paul M. Barrett ◽  
Marc E. H. Jones ◽  
Scott Moore-Fay ◽  
Susan E. Evans
Keyword(s):  
Middle Jurassic ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Sister Group ◽  
Late Triassic ◽  
Sister Group Relationship ◽  
New Taxon ◽  
Crown Group ◽  
History Of ◽  
Isle Of Skye

The discovery of a new stem turtle from the Middle Jurassic (Bathonian) deposits of the Isle of Skye, Scotland, sheds new light on the early evolutionary history of Testudinata. Eileanchelys waldmani gen. et sp. nov. is known from cranial and postcranial material of several individuals and represents the most complete Middle Jurassic turtle described to date, bridging the morphological gap between basal turtles from the Late Triassic–Early Jurassic and crown-group turtles that diversify during the Late Jurassic. A phylogenetic analysis places the new taxon within the stem group of Testudines (crown-group turtles) and suggests a sister-group relationship between E. waldmani and Heckerochelys romani from the Middle Jurassic of Russia. Moreover, E. waldmani also demonstrates that stem turtles were ecologically diverse, as it may represent the earliest known aquatic turtle.

scholarly journals The complicated and surprisingly early origin of the pterodactyloid bauplan

2017 ◽  
Author(s):  
David M. Unwin
Keyword(s):  
Phylogenetic Analysis ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Upper Jurassic ◽  
Anatomical Changes ◽  
History Of ◽  
Fifth Toe ◽  
Early Origin ◽  
Early Late ◽  
Complex Evolutionary History

The origin of the pterodactyloid bauplan from that of non-monofenestratan (‘rhamphorhynchoid’) pterosaurs involved extensive anatomical changes and had profound consequences for the evolutionary history of Pterodactyloidea, a clade that dominated the aerial realm throughout the Cretaceous. This important evolutionary transformation, about which almost nothing was known for almost two centuries, is now rapidly coming into focus thanks to a plethora of new pterosaur fossils from the Middle and Upper Jurassic of South America, Europe and China. So far, however, these finds have largely been considered in isolation from each other and few have been thoroughly evaluated. Phylogenetic analysis, combined with improved stratigraphic data for all potentially relevant taxa including putative non-pterodactyloid monofenstratans (NPMs) and the oldest known pterodactyloids (e.g. Liaodactylus) was used to generate a new map of the anatomical transformations and temporal history of the non-monofenestratan–pterodactyloid transition. Evolution of the pterodactyloid skull construction predates the Middle Jurassic, but remains almost completely undocumented by fossils. Liaodactylus reveals that innovation in pterodactyloid skull anatomy and the appearance of derived features was well underway prior to the Upper Jurassic. Douzhanopterus, a derived NPM, demonstrates that elongation of the metacarpus and reduction of the tail and fifth toe (classic pterodactyloid synapomorphies) also predates the Upper Jurassic, but disjunction in the degree of their development across taxa is not consistent with simple explanations such as ‘adaptation for flight’. Overall, late Early to early Late Jurassic pterosaurs were much more diverse and had a far more complex evolutionary history than heretofore recognised.

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