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[Ornithology • 2017] Myzomela irianawidodoae • A Colourful New Species of Myzomela Honeyeater from Rote Island in eastern Indonesia ---ScRaBBlE

Myzomela irianawidodoae Prawiradilaga, Baveja, Suparno, Ashari, Ng, Gwee, Verbelen & Rheindt, 2017  photo:   Philippe Verbelen  e-journ...

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Showing posts with label Journal: Cretaceous Research. Show all posts
Showing posts with label Journal: Cretaceous Research. Show all posts

Wednesday, March 20, 2019

[Paleontology • 2017] Chenanisaurus barbaricus • An Abelisaurid from the latest Cretaceous (late Maastrichtian) of Morocco, North Africa ---ScRaBBlE


Chenanisaurus barbaricus  
 Longrich, Pereda-Suberbiola, Jalil, Khaldoune & Jourani, 2017  


 Abstract
During the latest Cretaceous, distinct dinosaur faunas were found in Laurasia and Gondwana. Tyrannosaurids, hadrosaurids, and ceratopsians dominated in North America and Asia, while abelisaurids and titanosaurids dominated in South America, India, and Madagascar. Little is known about dinosaur faunas from the latest Cretaceous of Africa, however. Here, a new abelisaurid theropod, Chenanisaurus barbaricus, is described from the upper Maastrichtian phosphates of the Ouled Abdoun Basin in Morocco, North Africa on the basis of a partial dentary and isolated teeth. Chenanisaurus is both one of the largest abelisaurids, and one of the youngest known African dinosaurs. Along with previously reported titanosaurid remains, Chenanisaurus documents the persistence of a classic Gondwanan abelisaurid-titanosaurid fauna in mainland Africa until just prior to the end-Cretaceous mass extinction. The animal is unusual both in terms of its large size and the unusually short and robust jaw. Although it resembles South American carnotaurines in having a deep, bowed mandible, phylogenetic analysis suggests that Chenanisaurus may represent a lineage of abelisaurids that is distinct from those previously described from the latest Cretaceous of South America, Indo-Madagascar, and Europe, consistent with the hypothesis that the fragmentation of Gondwana led to the evolution of endemic dinosaur faunas during the Late Cretaceous.

Keywords: Dinosauria; Theropoda; Ceratosauria; Abelisauridae; Gondwana; Biogeography

Fig. 3. Holotype of Chenanisaurus barbaricus, left dentary OCP DEK-GE 772.
A, lateral view, B, medial view, C, dorsal view.

Abbreviations: gr, vascular grooves; idp, interdental plates; nvf, neurovascular foramina; sd, supradentary bone; sym, symphysis; vas, vascular grooves.
DOI: 10.1016/j.cretres.2017.03.021 

Systematic paleontology
Dinosauria Owen (Owen, 1842)
Saurischia Seeley (Seeley, 1888)

Theropoda Marsh (Marsh, 1881)
Ceratosauria Marsh (Marsh, 1884)

Abelisauridae Bonaparte and Novas (Bonaparte and Novas, 1985)

Chenanisaurus barbaricus new genus and species

Etymology. The genus name refers to the Sidi Chennane phosphate mines, the type locality, and Greek ‘sauros, ‘lizard’. The species name is derived from the Greek barbaros, “savage” or “barbaric” and also refers to Barbary, a name historically used for Morocco and the northwest coast of Africa.

Diagnosis. Large abelisaurid characterized by a proportionately deep mandible, dentary bowed in lateral view, lateral groove and associated foramina located high on dentary; anterodorsal margin of dentary downturned in lateral view; massive symphysis, with anterior margin of symphysis vertical in lateral view; tip of jaws broad, with dentaries meeting at an obtuse angle.

Holotype. OCP DEK-GE 772, anterior end of the left dentary ( Fig. 3 ;  Fig. 4).


Horizon and Locality. The type specimen is reported as coming from the upper Maastrichtian (Couche III) of Sidi Chennane; the pale white color of the bone and the color of the associated matrix are consistent with the preservation seen in other material recovered from this locality. The isolated premaxillary teeth come from the upper Maastrichtian (Couche III) of Sidi Daoui. The maxillary tooth is of unknown provenance but likely comes from either Sidi Chennane or Sidi Daoui. All specimens come from the Ouled Abdoun Basin, Morocco North Africa (Fig. 1).



Fig. 9. Chenanisaurus barbaricus shown to scale with the Couche III titanosaur. 



Nicholas R. Longrich, Xabier Pereda-Suberbiola, Nour-Eddine Jalil, Fatima Khaldoune and Essaid Jourani. 2017. An Abelisaurid from the latest Cretaceous (late Maastrichtian) of Morocco, North Africa. Cretaceous Research. In Press. DOI: 10.1016/j.cretres.2017.03.021

  
             

"Chenanisaurus barbaricus" ....by lythronax-argestes lythronax-argestes.deviantart.com/art/Chenanisaurus-barbaricus-671571810

New moderately-sized abelisaur. I thought the silhouette in the paper was too majungasaurine, so I made my own with blackjack and hookers.
Dentary line drawing from Longrich et al. (2017), silhouette from Rugops by Crizz30 on Commons, human from Andrew Farke on Phylopic as usual.
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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل
او
شاهد هذا الفيديو القصير لطريقة التحميل البسيطة


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.

[PaleoOrnithology • 2017] An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia ---ScRaBBlE


An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia. 
Zelenkov, Averianov & Popov, 2017

elementy.ru   Illustration: Andrey Atuchin 

Abstract
Ornithuromorph birds (the clade which includes modern avian radiation) first appeared in the Early Cretaceous in Asia and achieved a great diversity during the latest ages of the Late Cretaceous (Campanian and Maastrichtian). The evolutionary history of orithuromorphs during the first 17 MYAs of the Late Cretaceous (Cenomanian to Santonian ages) remains very poorly known, as the fossil record for this time interval is largely restricted to several isolated finds of the classic avian genus Ichthyornis in North America. Here we describe an isolated distal tibiotarsus of an evolutionary advanced bird, morphologically similar to Ichthyornis, from the middle Cenomanian of Saratov Province, European Russia. This is the first documentation of an Ichthyornis-like bird in the Old World. The find further constitutes only the second pre-Campanian record of the Late Cretaceous Ornithuromorpha in Eurasia, the second record of Cenomanian birds in Russia. This discovery shows that Ichthyornis-like birds enjoyed a wide geographical distribution as early as the beginning of the Late Cretaceous. Given that the earliest and the most primitive ornithuromorph birds are known from Asia, the new find supports a Eurasian origin for Ichthyornithidae.

Keywords: Cenomanian; East Europe; Ornithuromorpha; Palaeobiogeography


Systematic paleontology
Aves Linnaeus 1758
Ornithuromorpha Chiappe et al. 1999
Ornithurae Haeckel 1866
?Ichthyornithidae Marsh 1873

Gen. et sp. indet.

Material. Specimen PIN 5554/1, distal fragment of a right tibiotarsus.

Locality and horizon. Site SNB-2a, Nizhnyaya Bannovka, Krasnoarmeisk District, Saratov Province, Russia; Middle Member, Melovatka Formation, middle Cenomanian, lower Upper Cretaceous.



Fig. 2. Specimen PIN 5554/1, distal tibiotarsus of an Ichthyornis-like bird from the middle Cenomanian of European Russia. A, lateral view; B, cranial view; C, medial view; D, caudal view; E, proximal view; F, distal view; G, interpretative drawing of the cranial view.
Abbreviations: cl, condylus lateralis; cm, condylus medialis; conc, concavity; csic, concavities within sulcus intercondylaris; ?dep, depression; em, epicondylus medialis; sic, sulcus intercondylaris; se, sulcus extensorius; tub, tuberosity. 


Conclusions
A partial tibiotarsus from the middle Cenomanian of the Nizhnyaya Bannovka locality in Saratov Province (European Russia) belongs to an evolutionary advanced ornithuromorph bird, similar in size and morphology to the North American Ichthyornis. This is the first reliable documentation of Ichthyornis-like birds in the Old World, because previously referred specimens indeed belong to Enantiornithes. This discovery confirms a wide geographic distribution of Ichthyornis-like birds already in the beginning of the Late Cretaceous and supports the Eurasian origin of Ichthyornithidae. The new specimen is further the first pre-Campanian Late Cretaceous ornithuromorph bird in Eurasian known from postcranial material.


Nikita V. Zelenkov, Alexander O. Averianov and Evgeny V. Popov. 2017. An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia.
 
Cretaceous Research. 75; 94–100. DOI: 10.1016/j.cretres.2017.03.011


Поволжский ихтиорнис • Никита Зеленков • Научная картинка дня на «Элементах» • Палеонтология https://elementy.ru/kartinka_dnya/307/Povolzhskiy_ikhtiornis

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل
او
شاهد هذا الفيديو القصير لطريقة التحميل البسيطة


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] Soriatitan golmayensis • A New Brachiosauridae Sauropod Dinosaur from the lower Cretaceous of Europe (Soria Province, Spain) ---ScRaBBlE


Soriatitan golmayensis
Royo-Torres, Fuentes, Meijide, Meijide-Fuentes & Meijide-Fuentes, 2017

 Abstract
A new dinosaur sauropod from the Golmayo Formation (upper Hauterivian-lower Barremian) in Soria province (Spain) is described as Soriatitan golmayensis gen. et sp. nov. The new material consists of one tooth, three dorsal vertebrae with ribs, a partial sacrum, five caudal centra, two caudal vertebral spines, one chevron, a humerus, an ulna, a radius, two partial ilia, two ischia, a fragment of pubis, and a partial femur. Cladistic analysis identified the material as belonging to Brachiosaruidae within Titanosauriformes. Sauropod material from the Golmayo Formation shares a diagnostic feature with Abydosaurus, Cedarosaurus, Tastavinsaurus and Venenosaurus including anteriorly deflected anterior–middle caudal neural spines and with Cedarosaurus a proximodistally straight lateral margin between the proximal head and the shaft of the humerus. Eight characters are potential autapomorphies in the sauropod from Spain, including the presence of a large rectangular ventral ridge below the preacetabular process of the ilium, the same length of the pubic and ischiadic blades in the ischium, and two lateral ridges in the lateral area of the deltopectoral crest of the humerus. The presence of Early Cretaceous brachiosarids in both, North America and Europe, give support to the hypothesis of a connection between the tectonic plates of these continents at some point during the Early Cretaceous.

Keywords: Soriatitan golmayensis; Golmayo Formation; Hauterivian-Barremian; Brachiosauridae; Sauropod; Europe; North America



 

Systematic palaeontology

Saurischia Seeley, 1887
Sauropoda Marsh, 1878
Neosauropoda Bonaparte, 1986

Titanosauriformes Salgado, Coria & Calvo, 1997
Brachiosauridae Riggs, 1904

Soriatitan gen. nov.
Etymology: From the Spanish province Soria where the dinosaur was found and from the Greek “titan” meaning giant in Greek mythology.

Soriatitan golmayensis sp. nov.

Etymology: In honor of the Golmayo village where the Zorralbo I site is located.



Conclusions: 
This study describes a new species of sauropod, Soriatitan golmayensis (MNS 2001/122) from the Golmayo Formation (upper Hauterivian–lower Barremian) located in Zorralbo I site in Golmayo village (Soria, Spain). This sauropod is classified as a Brachiosauridae within Titanosauriformes supported by two different phylogenetic analyses. Soriatitan shares the presence of anteriorly deflected anterior–middle caudal neural spines with CedarosaurusVenenosaurus and Tastavinsaurus, and a proximodistally straight lateral margin between the proximal head and the humerus shaft with Cedarosaurus. Eight characters are newly identified and are considered potential diagnostic criteria for the new possible genus and species: the caudal ribs develop a pointed anterior ridge in the middle; posterior caudal vertebra with large postzygapophyses; presence of a lateral fossa in every postzygapophysis in the posterior caudal vertebra; the presence of a rectangular ventral ridge cranial to the pubic process and below the preacetabular process in the ilium; ischiadic peduncle in the ilium three times longer in lateromedially than anteropospestiorly; the same length of the pubic peduncle and distal blade in the ischia; two lateral ridges in the lateral area of the deltopectoral crest; and the presence of the two ridges in the medial projection of the humerus head. At the moment, Soriatitan golmayensis is the first and the only brachiosarid described from the Early Cretaceous of Europe. The presence of the Early Cretaceous brachiosarid sauropods common to North America and Europe support to the presence of a possible bridge between these plates, prior to the late Hauterivian–Barremian.

  
Rafael Royo-Torres, Carolina Fuentes, Manuel Meijide, Federico Meijide-Fuentes and Manuel Meijide-Fuentes. 2017. A New Brachiosauridae Sauropod Dinosaur from the lower Cretaceous of Europe (Soria Province, Spain). Cretaceous Research.  80; 38–55DOI: 10.1016/j.cretres.2017.08.012

Identificado en Soria un nuevo saurópodo de más de 13 metros de longitud:  diariosigloxxi.com/texto-ep/mostrar/20170907150739/identificado-soria-nuevo-sauropodo-13-metros-longitud

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل
او
شاهد هذا الفيديو القصير لطريقة التحميل البسيطة


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] Redescription of the Elasmosaurid Plesiosaurian Libonectes atlasense from the Upper Cretaceous of Morocco ---ScRaBBlE


Sachs & Kear, 2017. Redescription of Libonectes atlasense    DOI: 10.1016/j.cretres.2017.02.017 

Illustration by Hyrotrioskjan   hyrotrioskjan.deviantart.com

Highlights
• The Late Cretaceous elasmosaurid species Libonectes atlasense and Libonectes morgani are likely synonymous.
• Fossils assigned to Libonectes morgani collectively constitute one of the best-known Elasmosaurid taxa.
• The palaeogeographical distribution of Libonectes morgani evidences trans-Atlantic dispersal amongst multiple Late Cretaceous plesiosaurian clades.

Abstract
The holotype of Libonectes atlasense is an almost complete skeleton from Upper Cretaceous (mid-Turonian) rocks of the Goulmima area in eastern Morocco. Initial assessment of this specimen in 2005 proposed generic referral based on stratigraphical contemporaneity with Libonectes morgani from the Cenomanian–Turonian of Texas, U.S.A. Nevertheless, relative differences in the profile of the premaxillary-maxillary tooth row, position of the external bony nasal opening, number of teeth and rostral inclination of the mandibular symphysis, proportions of the axial neural arch, and number of cervical and pectoral vertebrae were used to distinguish between these species. As part of an on-going comparative appraisal of elasmosaurid plesiosaurian osteo-anatomy, we re-examined the type and formally referred material of both L. atlasense and L. morgani in order to establish species validity, as well as compile a comparative atlas for use in future works. Our inspections revealed that these reportedly distinct species-level fossils are in fact virtually indistinguishable in gross morphology. Indeed, the only substantial difference occurs in relative prominence of the midline keel along the mandibular symphysis, which might be explained by intraspecific variation. Furthermore, our observations permit an amendment to the published generic diagnosis of Libonectes with the confirmation of important states such as the likely presence of a pectoral bar, distocaudal expansion of the humerus, and an epipodial foramen. In addition, novel features include a prominent ‘prong-like’ ventral midline process on the coracoids, and the development of a median pelvic bar that encloses a central fenestration. The composite remains of L. morgani thus constitute one of the most complete elasmosaurid skeletal hypodigms documented worldwide, and evidence a trans-Atlantic distribution for this apparently dispersive species during the early–Late Cretaceous.

Libonectes
Illustration by Hyrotrioskjan   hyrotrioskjan.deviantart.com 



Sven Sachs and Benjamin P. Kear. 2017. Redescription of the Elasmosaurid Plesiosaurian Libonectes atlasense from the Upper Cretaceous of Morocco. Cretaceous Research.  74; 205–222.   DOI: 10.1016/j.cretres.2017.02.017

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل
او
شاهد هذا الفيديو القصير لطريقة التحميل البسيطة


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] Tratayenia rosalesi • A New Megaraptoran Theropod Dinosaur from the Upper Cretaceous Bajo de la Carpa Formation of northwestern Patagonia ---ScRaBBlE


Tratayenia rosalesi 
Porfiri, Juárez Valieri, Santos & Lamanna, 2018

  DOI: 10.1016/j.cretres.2018.03.014 
Illustration: Andrew McAfee

Abstract
We describe Tratayenia rosalesi gen. et sp. nov., a new megaraptoran theropod dinosaur from the Upper Cretaceous of Patagonia, Argentina. The holotype consists of a well-preserved, mostly articulated series of dorsal and sacral vertebrae, two partial dorsal ribs, much of the right ilium, and pubis and ischium fragments. It was found in a horizon of the Upper Cretaceous (Santonian) Bajo de la Carpa Formation of the Neuquén Group in the Neuquén Basin exposed near the town of Añelo in Neuquén Province of northwestern Patagonia. Phylogenetic analysis recovers Tratayenia within the Gondwanan megaraptoran subclade Megaraptoridae. The new taxon exhibits similarities to other megaraptorids such as Aerosteon riocoloradensis, Megaraptor namunhuaiquii, and Murusraptor barrosaensis, but also presents differences in the architecture of the dorsal and sacral vertebrae and the morphology of the ilium. Tratayenia is the first megaraptoran that unequivocally preserves the complete sequence of sacral vertebrae, thereby increasing knowledge of the osteology of the clade. Moreover, depending on the chronostratigraphic ages of the stratigraphically controversial megaraptorids Aerosteon and Orkoraptor burkei, as well as the phylogenetic affinities of several fragmentary specimens, the new theropod may be the geologically youngest megaraptorid or megaraptoran yet discovered. Tratayenia is also the largest-bodied carnivorous tetrapod named from the Bajo de la Carpa Formation, reinforcing the hypothesis that megaraptorids were apex predators in southern South America from the Turonian through the Santonian or early Campanian, following the extinction of carcharodontosaurids.

Keywords: Theropoda; Megaraptora; Megaraptoridae; Bajo de la Carpa Formation; Upper Cretaceous; Patagonia; Argentina


Figure 3. Preserved dorsal vertebrae and sacrum of  Tratayenia rosalesi gen. et sp. nov. (MUCP v1162). A, left lateral view. B, right lateral view.

Figure 2. Tentatively reconstructed body silhouette of  Tratayenia rosalesi gen. et sp. nov. showing the bones preserved in the holotype (MUCP v1162). Body regions not preserved in Tratayenia are based primarily on corresponding elements of the following megaraptorid species: cranium (Megaraptor namunhuaiquii, Murusraptor barrosaensis), mandible (Australovenator wintonensis, M. barrosaensis), postcranial axial skeleton (Aerosteon riocoloradensis, M. namunhuaiquii), appendicular skeleton (A. riocoloradensis, A. wintonensis, M. namunhuaiquii). Scale bar equals 1 m.

Systematic paleontology
 Dinosauria Owen, 1842
 Theropoda Marsh, 1881
 Tetanurae Gauthier, 1986

 Megaraptora Benson, Carrano, and Brusatte, 2010
 Megaraptoridae Novas, Agnolín, Ezcurra, Porfiri, and Canale, 2013

 Tratayenia rosalesi gen. et sp. nov. 

Etymology. Genus name for Tratayén, the locality where the holotype was collected; species name in honor of Diego Rosales, the discoverer of the specimen. 

....



Conclusions: 
Tratayenia rosalesi is a new taxon of megaraptoran theropod, the first to be described from the Santonian Bajo de la Carpa Formation of the Neuquén Group. Its discovery constitutes a previously unreported stratigraphic occurrence in the megaraptorid fossil record of northern Patagonia. The elevated pneumaticity and morphological resemblance of the axial and pelvic elements of Tratayenia to those of the megaraptorids Aerosteon riocoloradensis and Murusraptor barrosaensis suggests 851 particularly close relationships between these three taxa. Nevertheless, Tratayenia also exhibits a number of unique morphologies that justify the erection of a new taxon. The holotype is the first megaraptoran specimen to preserve a nearly complete sequence of middle and posterior dorsal vertebrae and the complete sacrum, which augments knowledge of serial variation in this area of the axial skeleton. Tratayenia rosalesi is the largest carnivorous taxon known from the Bajo de la Carpa Formation, and, like other Patagonian megaraptorids, was likely the apex predator in its paleoecosystem. 


Juan D. Porfiri, Rubén D. Juárez Valieri, Domenica D.D. Santos and Matthew C. Lamanna. 2018. A New Megaraptoran Theropod Dinosaur from the Upper Cretaceous Bajo de la Carpa Formation of northwestern Patagonia. Cretaceous Research. In Press.  DOI: 10.1016/j.cretres.2018.03.014



  


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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل
او
شاهد هذا الفيديو القصير لطريقة التحميل البسيطة


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] Semi-aquatic Adaptations in A Spinosaur from the Lower Cretaceous of Brazil ---ScRaBBlE


A Spinosaurinae at the Aptian-Albian lagunar/shallow marine environment of the Romualdo Formation, Araripe Basin, NE Brazil.

in Aureliano, Ghilardi, Buck, et al., 2018. 
Illustration by Julio Lacerda.

Highlights
• Spinosaur histology is here described for the first time.
• Extreme bone compactness (osteosclerosis) was present in Brazilian Spinosaurinae.
• These modifications appeared millions of years before the Moroccan Spinosaurus.
• One of the largest spinosaur specimens from the Early Cretaceous of South America.

Abstract
Spinosaurinae are known to have a strong relationship with aquatic environments, involving several anatomical adaptations. Nonetheless, this group of theropods remains enigmatic, due to the relative incompleteness of its fossil record. A large partial tibia from the Aptian-Albian Romualdo Formation, Northeast Brazil, is herein described through anatomical comparisons and paleohistological analyzes. It features characteristics previously only observed in Spinosaurus aegyptiacus, which includes a reduced fibular crest and an osteosclerotic condition. The later, a character supported as correlated with semi-aquatic habits in many limbed vertebrates. The results presented here support high bone compactness being already present in Brazilian Spinosaurinae millions of years before the Moroccan Spinosaurus. Furthermore, histological analyses demonstrate the Romualdo Formation specimen was a young subadult still growing fast by the time of its death, and suggests Araripe Basin Spinosaurinae could have grown larger than previously thought. This work contributes to a better paleobiological and ecological understanding of South American spinosaurs, and helps fill a gap in the macroevolutionary comprehension of Spinosaurinae. Ultimately, it also contributes to further advancing the paleoecological characterization of the Romualdo Formation.

Keywords: Paleohistology; Araripe basin; Theropoda; Megalosauroidea; Spinosaurinae


Systematic paleontology

Dinosauria Owen, 1842
Theropoda Marsh, 1882

Tetanurae Gauthier, 1986
Megalosauroidea Fitzinger, 1843

Spinosauridae Stromer 1915
Spinosaurinae Stromer, 1915

gen. et. sp. indet.

Referred material: LPP-PV-0042, a fragmentary tibia.

Locality and horizon: Exact geological and geographical provenance is unknown, but the fossil was collected in the Araripe area, Northeast Brazil. Outcrops of the Lower Cretaceous Santana Group (Araripe Basin) are worldwide known for providing well-preserved fossils and are located in the Araripe region. 

Fig. 6. 1. Spinosaurinae remains currently recovered from the Romualdo Formation, Araripe Basin, Brazil. Not to scale.
 A, USP GP/2T-5, holotype of Angaturama limai ( Kellner & Campos, 1996), fragmentary anterior tip of skull.
B, SMNS 58022, holotype of Irritator challengeri (Sues et al., 2002) (originally mistakenly identified as a maniraptor by Martill et al., 1996), partial posterior portion of skull and mandible.
C, MN 4743-V, incomplete indeterminate spinosaur sacral and caudal vertebrae series (S3, S4, S5, C1, C2. C3, C4, C4, C6) (Bittencourt & Kellner, 2004).
D, MN 7021-V, indeterminate spinosaur rib (Machado & Kellner, 2007). E, MN4819-V, incomplete indeterminate spinosaur pubis, pelvis, dorsal, sacral and caudal vertebrae (d, S1, S2, S3, S4, S5, C1), incomplete indeterminate spinosaur right manus, fragmentary right tibia and femur ( Machado et al., 2008; Machado and Kellner, 2009 ; Machado, 2010).
 F, LPP-PV-0042, Spinosaurinae indet. metaphysis of left tibia described in this work. Skeletal reconstruction made by Tito Aureliano, based on the work by Scott Hartman and Marcos Sales. 


2. Romualdo Spinosaurinae specimens to scale. A, Angaturama USP GP/2T (∼8.3 m, on the reconstruction by Sales & Schultz, 2017). B, Irritator SMNS 58022 (∼6.5 m, from the reconstruction by Sales & Schultz, 2017). C, Spinosaurinae indet. MN4819-V (∼5.9 m; Machado et al., 2008). D, Spinosaurinae indet. LPP-PV-0042 (∼10 m; this work). Scale bar in 7.2 is 1 m. 

Fig. 8. Reconstruction of a Spinosaurinae at the Aptian-Albian lagunar/shallow marine environment of the Romualdo Formation, Araripe Basin, NE Brazil. 
Illustration by Julio Lacerda.

Fig. 7. Inferred food web of the Aptian-Albian Romualdo Formation, Northeast Brazil. Vertebrate silhouettes are highlighted in black. Trophic relations are represented by arrows, of which solid bold red represent ecological interactions with direct fossil evidence from Romualdo Formation; solid black indicate putative trophic interactions with general theoretical support; and dashed grey represent weak or uncertain but plausible trophic links.
1, Spinosaurinae; 2, small to medium sized terrestrial theropods; 3, pterosaurs; 4, semi-aquatic crocodyliforms; 5, terrestrial omnivorous crocodyliforms; 6, semi-aquatic chelonians; 7, large fishes; 8, small fishes; 9, plants; 10, macroinvertebrates; 11, plankton. See Text S1 in the Supplementary material for list of references. Spinosaurinae silhouette by Tito Aureliano. Other silhouettes from Phylopic (http://phylopic.org/), courtesy of Almandine (vectorized by T. Michael Keesey), FunkMonk (adapted), Hans Hillewaert, John Conway, Melissa Broussard, Nobu Tamura (vectorized by T. Michael Keesey), Olegivvit, Robert Gay and Sergio A. Muñoz-Gómez.  

Conclusion: 
The Romualdo Formation specimen LPP-PV-0042 comprises a fragmentary tibia with a reduced fibular crest and osteosclerotic histology previously only observed in Spinosaurus aegyptiacus, supporting that this unique feature was already present in Brazilian Spinosaurinae (basal Spinosaurinae) during the Aptian-Albian time, at least 10 myr before the Moroccan Spinosaurus.

Histological analyses suggest LPP-PV-0042 was a young, fast growing subadult and also that the bone microstructure varies a lot across the cross-section, probably due to areas of muscle insertion. The latter observation suggests that caution is needed when describing bone histology of dinosaurs, since only one slice from the shaft is not always representative of the entire histology of the bone.

Furthermore, the current specimen represents one of the largest spinosaurs from this unit so far (∼10 m in reconstructed TL). It was larger than the Irritator holotype and possibly larger than Angaturama holotype as well. Considering the subadult status inferred from its histology, the referred individual would have grown even larger.

The Romualdo paleoenvironment could support large predators with semi-aquatic habits due to its high productivity and diversity of aquatic species as an ecotone. Spinosaurinae from Romualdo Formation probable occupied the position of apex predators different.

Thus, the skeletal element LPP-PV-0042 from the Romualdo Formation, although fragmentary, has provided much information about Brazilian Spinosaurinae paleobiology and ecology. Moreover, it gives new insight into the evolution of semi-aquatic adaptations in this group, revealing the need to investigate other taxa within the clade and expand the search for more spinosaur fossils.




  


Tito Aureliano, Aline M. Ghilardi, Pedro V. Buck, Matteo Fabbri, Adun Samathi, Rafael Delcourt, Marcelo A. Fernandes and Martin Sander. 2018. Semi-aquatic Adaptations in A Spinosaur from the Lower Cretaceous of Brazil. Cretaceous Research. In Press.  DOI: 10.1016/j.cretres.2018.04.024

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل
او
شاهد هذا الفيديو القصير لطريقة التحميل البسيطة


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.

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