[Paleontology • 2017] Zhongjianosaurus yangi • A New Tiny Dromaeosaurid Dinosaur from the Lower Cretaceous Jehol Group of western Liaoning and Niche Differentiation Among the Jehol Dromaeosaurids ---ScRaBBlE

Zhongjianosaurus yangi 

Xu & Qin, 2017 

Abstract 

The Early Cretaceous Jehol dromaeosaurids are taxonomically and morphologically diverse, and one of them, Microraptor zhaoianus, has been suggested to be among the smallest known non-avialan theropods. However, this idea is based on specimens of relatively early ontogenetic stages, and the lower limit of the mature body mass of Jehol dromaeosaurids thus remains unknown. Here we describe a new dromaeosaurid, Zhongjianosaurus yangi gen. et sp. nov., based on a specimen from the Lower Cretaceous Yixian Formation (the middle section of the Jehol Group) from Sihedang, Lingyuan County, Liaoning in Northeast China. While this new taxon is referable to the Microraptorinae, it differs from other microraptorine dromaeosaurids in numerous features, most notably the fusion of proportionally long uncinate processes to dorsal ribs, a humerus with a strongly medially offset proximal end and a large fenestra within the deltopectoral crest, an ulna slightly longer than the humerus, and an arctometatarsalian pes. Most significantly, the estimated 0.31 kg mass of the Z. yangi holotype of an adult individual confirms that some Jehol dromaeosaurids are among the smallest known non-avialan theropods. Our preliminary analysis demonstrates niche differentiation among the Jehol dromaeosaurids, a phenomenon rarely reported among Mesozoic dinosaurian faunas. 

Key words:  Lower Cretaceous, Jehol Group, Theropoda, Dromaeosauridae, small size, morphological variation, niche differentiation

 

Systematic paleontology

 Theropoda Marsh, 1881

 Tetanurae Gauthier, 1986

 Dromaeosauridae Matthew et Brown, 1922

Zhongjianosaurus yangi gen. et sp. nov.

 Etymology: The genus name and specific epithet are in honor of Yang Zhongjian (C.C. Young), who is the founder of vertebrate paleontology in China.

Locality and Horizon: Sihedang, Lingyuan County, Liaoning Province, China. Possibly Yixian Formation, Aptian, Cretaceous (Swisher et al., 2001).

Diagnosis: A tiny microraptorine theropod distinguishable from other microraptorines in the following autapomorphies: proportionally long ossified uncinate processes fused to dorsal ribs, widely arched furcula with slender and posteriorly curved clavicular rami, humeral proximal end strongly offset medially from humeral shaft, humeral internal tuberosity short, presence of large fenestra within humeral deltopectoral crest, humeral ulnar condyle hypertrophied, ulna slightly longer than humerus, ulnar olecranon process with posterior margin mediolaterally pinched, ulnar distal end bending anteriorly and strongly expanded laterally, proximal end of metacarpal II with strong ventrolateral extension, metacarpal III laterally bowed with longitudinal ventral groove, phalanx II-2 without proximodorsal lip and lacking strong dorsal arching, femoral head stout and lower than trochanteric crest, medial condyle of tibiotarsus distal end with a prominent distal extension, arctometatarsalian pes, and metatarsal II without ginglymus on distal end.

 

 Xing Xu and Zi-Chuan Qin. 2017. A New Tiny Dromaeosaurid Dinosaur from the Lower Cretaceous Jehol Group of western Liaoning and Niche Differentiation Among the Jehol Dromaeosaurids. Vertebrata PalAsiatica. In press.

http://www.ivpp.ac.cn/cbw/gjzdwxb/pressonline/201704/P020170410587218147108.pdf

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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.

[Paleontology • 2017] Moabosaurus utahensis • A New Sauropod From The Early Cretaceous (Aptian) of North America ---ScRaBBlE

Moabosaurus utahensis 

Britt, Scheetz, Whiting & Wilhite, 2017

   deepblue.lib.umich.edu/handle/2027.42/136227 

Abstract

 The Early Cretaceous was a time of dramatic change for sauropod dinosaurs in North America. Between the Late Jurassic-aged Morrison Formation and overlying Early Cretaceous strata, there was a dramatic decline in sauropod diversity. Here, we describe a new sauropod that adds to the diversity of the Early Cretaceous, from strata that can be no older than the early Aptian, (125 Ma) some 25 million years younger than the Morrison Formation. 

Moabosaurus utahensis, n. gen., n. sp., is diagnosed in part by the following suite of characters: axially thin ventral basioccipital with posteriorly sweeping basal tubera; low-spined cervical vertebrae with neural spines that range from shallowly notched on anterior cervical vertebrae to shallow, but widely notched on middle and some posterior cervical vertebrae; posterior cervical and anterior dorsal neural spines with extremely low, axially thin, laterally wide ridges at the level of the zygapophyses; some cervical ribs with bifid posterior shafts; anterior and posterior caudal vertebrae with strongly procoelous centra, middle caudal vertebrae with mildly procoelous centra, and distal caudal vertebrae with moderately-to-strongly procoelous centra.

 To determine the phylogenetic position of Moabosaurus we utilized three different datasets and performed four analyses. All results are in agreement that Moabosaurus is a neosauropod. The two most resolved trees indicate it is a macronarian, specifically a basal titanosauriform. The thick-walled, camerate presacral vertebrae and other characters, however, preclude a more highly nested position of Moabosaurus within either Titanosauriformes, which is characterized by moderately camellate presacral vertebrae, or Somphospondyli, which is characterized by fully camellate presacral vertebrae, including the neural arches. Incorporation of these and other characters, particularly those shared with Turiasaurus and Tendaguria, into phylogenetic analyses will help resolve the interrelationships of Moabosaurus with other neosauropods.

FIGURE 36 — Moabosaurus utahensis skeletal mount.
A composite of the holotypic dorsal vertebrae (BYU 14387) and referred elements plus a skull of Camarasaurus. The skeleton is 9.75 m long. 

 B.B. Britt, R.D. Scheetz, M.F. Whiting and D.R. Wilhite. 2017. Moabosaurus utahensis, n. gen., n. sp., A New Sauropod From The Early Cretaceous (Aptian) of North America. Contributions from the Museum of Paleontology, University of Michigan. 32(11); 189–243. deepblue.lib.umich.edu/handle/2027.42/136227

    

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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.

[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

او

من هنا

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.