[PaleoMammalogy • 2017] Durlstodon ensomi & Durlstotherium newmani • Highly Derived Eutherian Mammals from the earliest Cretaceous of southern Britain ---ScRaBBlE

the Purbeck lagoon at dusk with Durlstodon gen. nov. (left foreground), Durlstotherium gen. nov. (right and center foreground) and the theropod Nuthetes holding a captured Durlstotherium (centre middle distance). 

A. Durlstotherium newmani gen. et sp. nov., NHMUK PV M 99991.
B. Durlstodon ensomi gen. et sp. nov., NHMUK PV M 99992.

Artwork by Mark Witton. @MarkWitton 

DOI: 10.4202/app.00408.2017 

Eutherian mammals (Placentalia and all mammals phylogenetically closer to placentals than to marsupials) comprise the vast majority of extant Mammalia. Among these there is a phenomenal range of forms and sizes, but the origins of crown group placentals are obscure. They lie within the generally tiny mammals of the Mesozoic, represented for the most part by isolated teeth and jaws, and there is strongly conflicting evidence from phenomic and molecular data as to the date of origin of both Eutheria and Placentalia. The oldest purported eutherians are Juramaia from the Upper Jurassic of China, and Eomaia and Acristatherium from the Lower Cretaceous, also of China. Based on dental characters and analyses of other morphological and molecular data, doubt has recently been cast on the eutherian affinities of the Chinese taxa and consequently on the date of emergence of Eutheria. Until now, the only tribosphenic mammal recorded from the earliest Cretaceous (Berriasian) Purbeck Group of Britain was the stem tribosphenidan Tribactonodon. Here we document two new tribosphenic mammals from the Purbeck Group, Durlstotherium gen. nov. and Durlstodon gen. nov., showing highly derived eutherian molar characters that support the early emergence of this clade, prior to the Cretaceous.

Key words: Mammalia, Eutheria, dentition, Early Cretaceous, Purbeck Group, Britain.

Fig. 5. Normal light photographs of studied specimens of eutherian mammal teeth from the Berriasian Purbeck Group of Dorset, southern England; in mesial (A1, B1), distal (A2, B2), lingual (A3, B3), and labial (A4, B4) views.
 A. Durlstotherium newmani gen. et sp. nov., NHMUK PV M 99991. B. Durlstodon ensomi gen. et sp. nov., NHMUK PV M 99992.

Systematic palaeontology

Class Mammalia Linnaeus, 1758

Subclass Tribosphenida McKenna, 1975

Infraclass Eutheria Gill, 1872

Order and Family incertae sedis

Genus Durlstotherium nov.

Type species: Durlstotherium newmani sp. nov., monotypic, see below.

Etymology: In reference to Durlston Bay, Dorset, UK, the locality from where the holotype and only specimen was obtained; and from Greek, therion, beast; a commonly used suffix in the names of mammals.; In honour of Charlie Newman, recognising his intimate local knowledge, willingly shared, and his help in the field.

Genus Durlstodon nov. 

Type species: Durlstodon ensomi sp. nov., monotypic, see below.

Etymology: In reference to Durlston Bay, Dorset, UK, the locality from where the holotype and only specimen was obtained; and from Greek, odontos, tooth.; In honour of Paul Ensom, recognising his major contribution to Purbeck palaeontology.

Fig. 7. Artist’s impression of the Purbeck lagoon at dusk with Durlstodon gen. nov. (left foreground), Durlstotherium gen. nov. (right and center foreground) and the theropod Nuthetes holding a captured Durlstotherium (centre middle distance).

Artwork by Mark Witton. @MarkWitton

DOI: 10.4202/app.00408.2017

Steven C. Sweetman, Grant Smith and David M. Martill. 2017. Highly Derived Eutherian Mammals from the earliest Cretaceous of southern Britain. Acta Palaeontologica Polonica. in press. DOI: 10.4202/app.00408.2017

twitter.com/MarkWitton/status/927801001633042432

Placental mammal ancestor in Europe found in Britain | Elsa Panciroli https://www.theguardian.com/science/2017/nov/07/teeth-discovered-in-dorset-reveal-secrets-of-the-origins-of-modern-mammals

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

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شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Paleontology • 2017] On the Largest Ichthyosaurus: A New Specimen of Ichthyosaurus somersetensis Containing An Embryo ---ScRaBBlE

Ichthyosaurus somersetensis Lomax and Massare, 2017
 (NLMH 106234) from the Lower Jurassic (lower Hettangian) of Doniford Bay, Watchet, Somerset, UK

DOI: 10.4202/app.00376.2017 

A formerly undescribed Ichthyosaurus specimen from the collection of the Niedersächsisches Landesmuseum (Lower Saxony State Museum) in Hannover, Germany, provides valuable new information. The skeleton was collected from the Lower Jurassic strata (lower Hettangian, Blue Lias Formation) of Doniford Bay, Somerset, UK. However, the specimen is a composite as almost the entire tail has been added and other parts are reconstructed. Regardless of the incomplete preservation, the estimated total length of this individual, based on the skull and precaudal length, is between 300 and 330 cm and it is thus the largest unequivocal example of the genus Ichthyosaurus. Cranial and postcranial characters, specifically from the maxilla, lacrimal, jugal, the humerus, and the ilium justify a referral to I. somersetensis. A fork-like shape of the proximal end of the ilium is unusual and has not been reported for any species of Ichthyosaurus. Likewise the presence of four elements in the third row of the hindfin, indicated by the presence of a bifurcation is novel for the species and has wider implications for the taxonomic utility of hindfins within the genus. The specimen also bears an embryo, which is only the third embryo known for Ichthyosaurus and the first to be positively identified to species level.

Key words: Ichthyosauria, Ichthyosaurus somersetensis, embryo, Jurassic, Hettangian, UK, Somerset.

Artist impression of pregnant Ichthyosaurus.

ILLUSTRATION: Joschua Knüppe

Fig. 2.  Skeleton of Ichthyosaurus somersetensis Lomax and Massare, 2017 (NLMH 106234) from the Lower Jurassic (lower Hettangian) of Doniford Bay, Watchet, Somerset, UK. 

Systematic palaeontology

Order Ichthyosauria de Blainville, 1835

Family Ichthyosauridae Bonaparte, 1841

Genus Ichthyosaurus De la Beche and Conybeare, 1821

Type species: Ichthyosaurus communis De la Beche and Conybeare, 1821; upper Hettangian–lower Sinemurian, Lower Jurassic of England, UK.

Ichthyosaurus somersetensis Lomax and Massare, 2017

 .....

Dean R. Lomax and Sven Sachs. 2017.  On the Largest Ichthyosaurus: A New Specimen of Ichthyosaurus somersetensis Containing An Embryo. Acta Palaeontologica Polonica. in press.  DOI: 10.4202/app.00376.2017

 www.app.pan.pl/archive/published/app62/app003762017.pdf

Largest 'Sea Dragon' Fossil Accidentally Discovered in Museum
on.natgeo.com/2wNrj9z   @NatGeo

 https://phys.org/news/2017-08-largest-ichthyosaurus-pregnant-mother-palaeontologists.html

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

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كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Paleontology • 2018] Lavocatisaurus agrioensis • A New Rebbachisaurid Sauropod from the Aptian–Albian, Lower Cretaceous Rayoso Formation, Neuquén, Argentina ---ScRaBBlE

Lavocatisaurus agrioensis 

Canudo, Carballido, Garrido & Salgado, 2018

DOI: 10.4202/app.00524.2018 

Illustration: Gabriel Lio. 

Rebbachisaurids are a group of basal diplodocimorph sauropods that diversified in Gondwana at the end of the Early Cretaceous and the beginning of the Late Cretaceous. It is a group of great palaeobiogeographical interest, for it  clearly illustrates various processes of dispersal throughout Gondwana and to Laurasia prior to the breakup of Africa and South America. However, the relationships within the group are still under discussion owing to the scarcity of cranial material that would help clarify them. In the present paper we describe the new rebbachisaurid Lavocatisaurus agrioensis gen. et  sp. nov. from the Aptian–Albian (Lower Cretaceous) of Neuquén (Argentina). Remains have been recovered belonging to an adult specimen (holotype) and two immature specimens (paratypes). Taken together, almost all the bones of the taxon are represented, including most of the cranium. Lavocatisaurus agrioensis gen. et sp. nov. is the first rebbachisaurid from Argentina with an almost complete cranium, making it possible to recognize differences with respect to other rebbachisaurids, such as the highly derived Nigersaurus. Among its most notable characters are the presences of a large preantorbital fenestra and maxillary teeth that are significantly larger than those of the dentary. Our phylogenetic study places Lavocatisaurus amongst basal rebbachisaurids, as the sister lineage to Khebbashia (the clade formed by Limaysaurinae + Rebbachisaurinae). This position, which is somewhat more derived than that previously suggested for Comahuesaurus and Zapalasaurus (the Argentinean rebbachisaurids closest in geographical and geological terms), reaffirms the presence of different basal rebbachisaurid lineages in the Early Cretaceous of Patagonia.

Key words: Dinosauria, Rebbachisauridae, phylogeny, Cretaceous, Rayoso Formation, Argentina.

Fig. 2. Rebbachisaurid sauropod Lavocatisaurus agrioensis gen. et sp. nov. from Agrio del Medio (Argentina), Aptian–lower Albian. A. MOZ-Pv1232, axis in lateral view (A1, photograph; A2, drawing); eight cervical vertebrae in lateral view view (A3, photograph; A4, drawing, ); anterior caudal vertebra in lateral view (A5); middle caudal vertebra in lateral view (A6); posterior caudal vertebra in lateral view (A7); posteriormost caudal vertebra in lateral view (A8); left tibia in lateral view (A9). B. MOZ-Pv 1255, left scapula from a juvenile specimen, in lateral view. C. Skeletal reconstruction based on the holotype and paratype specimens. Scale bars 10 cm. 

Saurischia Seeley, 1887

Sauropoda Marsh, 1878

Diplodocoidea Marsh, 1878 sensu Upchurch, 1995

Diplodocimorpha Calvo and Salgado, 1995

Rebbachisauridae Bonaparte, 1997

Genus Lavocatisaurus nov.

Etymology: In honour of the French researcher René Lavocat (1909–2007), who described Rebbachisaurus, the first known representative of Rebbachisauridae.

Lavocatisaurus agrioensis sp. nov.

Etymology: In reference to the locality of Agrio del Medio, from which the new species was found

Illustration: Gabriel Lio.  

Conclusions: 

Lavocatisaurus agrioensis is the first of the South American rebbachisaurids that preserves the rostral region of the cranium, which has allowed us to undertake a reliable enough reconstruction of the skull. The skull has a combination of morphological characters that justifies its definition as a new taxon within Rebbachisauridae along with the less derived rebbachisaurids from the Early Cretaceous of Argentina such as Zapalasaurus and Comahuesaurus. Our phylogenetic study situates Lavocatisaurus as the sister lineage of Khebbashia (Fig. 5). Lavocatisaurus is the most derived basal rebbachisaurid known to date, providing reliable information on the evolutionary steps that occurred just prior to the diversification of Rebbachisaurinae.

José I. Canudo, José L. Carballido, Alberto Garrido and Leonardo Salgado. 2018. A New Rebbachisaurid Sauropod from the Aptian–Albian, Lower Cretaceous Rayoso Formation, Neuquén, Argentina. Acta Palaeontologica Polonica. in press. DOI: 10.4202/app.00524.2018 

Scientists discover a new species of dinosaur 110 million years old in Argentina

 dicyt.com/news/scientists-discover-a-new-species-of-dinosaur-110-million-years-old-in-argentina

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

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شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.