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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 PaleoEnvironment. Show all posts
Showing posts with label PaleoEnvironment. Show all posts

Wednesday, March 20, 2019

[PaleoIchthyology • 2017] Eoanabas thibetana • Fossil Climbing Perch and Associated Plant Megafossils indicate A Warm and Wet Central Tibet During the late Oligocene ---ScRaBBlE


Eoanabas thibetana
Wu, Miao, Chang, Shi & Wang, 2017


Abstract
Understanding the Tibetan Plateau’s palaeogeography and palaeoenvironment is critical for reconstructing Asia’s climatic history; however, aspects of the plateau’s uplift history remain unclear. Here, we report a fossil biota that sheds new light on these issues. It comprises a fossil climbing perch (Anabantidae) and a diverse subtropical fossil flora from the Chattian (late Oligocene) of central Tibet. The fish, Eoanabas thibetana gen. et sp. nov., is inferred to be closely related to extant climbing perches from tropical lowlands in south Asia and sub-Saharan Africa. It has osteological correlates of a labyrinth organ, which in extant climbing perches gives them the ability to breathe air to survive warm, oxygen-poor stagnant waters or overland excursion under moist condition. This indicates that Eoanabas likewise lived in a warm and humid environment as suggested by the co-existing plant assemblage including palms and golden rain trees among others. As a palaeoaltimeter, this fossil biota suggests an elevation of ca. 1,000 m. These inferences conflict with conclusions of a high and dry Tibet claimed by some recent and influential palaeoaltimetry studies. Our discovery prompts critical re-evaluation of prevailing uplift models of the plateau and their temporal relationships with the Cenozoic climatic changes.


Systematic Palaeontology  

Teleostei Müller, 1845
Anabantiformes sensu Wiley and Johnson, 2010

Anabantoidei sensu Lauder and Liem, 1983
Anabantidae Bonaparte, 1839

Eoanabas thibetana gen. et sp. nov.

Etymology. The generic name combines ‘Eo-’ (Greek, early/primeval) with ‘Anabas’, the type genus of Anabantidae from tropical Asia. The specific name refers to Tibet, China.

Holotype. IVPP V 22782, a complete skeleton, part and counterpart (Fig. 1a,b).

Paratypes. Sixteen specimens are designated as paratypes (Supplementary Information).

Locality and Horizon. Jiangnongtangga (type locality) and Songwori in south Nima Basin and Dayu in Lunpola Basin in central Tibet (Supplementary Figs 1 and 2). Middle-upper part of Dingqing Formation, late Oligocene (Chattian) (ca. 26~23.5 Ma)6, 20, 26.

Diagnosis. A labyrinth fish displaying anabantid characteristics including a posterior notch of the opercle bounded by spines, a V-shaped strut on inner side of opercle and six to nine anal-fin spines. It shares with Asian anabantids the following derived characters: broad infraorbitals 3–5 completely covering the cheek, a sensory canal pore just behind sphenotic/pterotic junction and pelvic plate lying flat; and it shares with African anabantids some derived characters, e.g., sensory canal opening in between the infraorbitals, supraorbital commissure of the sensory canal absent and male postocular contact organ present.


Figure 1 A new fossil climbing perch, Eoanabas thibetana gen. et sp. nov. from the upper Oligocene of central Tibet. It resembles its extant tropical relatives in having a labyrinth organ for air breathing and postocular contact organ in male fishes for stimulating the female during a mating clasp.
(a) Photograph and (b) line drawing of holotype (IVPP V22782a), image horizontally rotated. (c) Photograph and (d) line drawing of the head of IVPP V18412a, red area in (d) representing muscular attachment facet.

Abbreviations: alm, attachment facet of levator operculi muscle; Cbr1, ceratobranchial of first gill arch; op.st, V-shaped struts on inner side of opercles.


Figure 2 Fossil climbing perch, Eoanabas thibetana gen. et sp. nov. from the upper Oligocene of central Tibet.
(a) Line drawing of the head of IVPP V18414a. (b) Photograph of IVPP V18414a. (c) Photograph of IVPP V18581a. (d) Scanning Electron Microscope (SEM) images of relics of labyrinth organ in (c), arrows pointing the pores on the lamellae. (e) Computerized tomography of labyrinth organ (lateral view) of Anabas testudineus (OP 435). (f) Cleared and stained head showing the labyrinth organ and associated structures of Anabas testudineus (collection no. OP 432). (g) Cleared and stained specimen of Anabas testudineus (collection no. OP 433). (h) Osteological restoration of Eoanabas, purported male; not to scale.

Images in (c), (d) are horizontally rotated. Abbreviations: br, branchiostegal rays; hp1, hypural 1; m., muscle; php, parhypural.



Feixiang Wu, Desui Miao, Mee-mann Chang, Gongle Shi and Ning Wang. 2017. Fossil Climbing Perch and Associated Plant Megafossils indicate A Warm and Wet Central Tibet During the late Oligocene. Scientific Reports. 7, Article number: 878.  DOI: 10.1038/s41598-017-00928-9 
ResearchGate.net/publication/316090334_Fossil_climbing_perch_and_associated_plant_megafossils_indicate_a_warm_and_wet_central_Tibet_during_the_late_Oligocene
IVPP.cas.cn/xwdt/tpxw/201706/t20170605_4807953.html

Feixiang Wu, Dekui He, Mee-mann Chang and Desui Miao. 2017. New light on the paleobiogeography of the labyrinth fishes. RESEARCH & KNOWLEDGE. 3(2); 63-64. DOI: 10.14456/randk.2017.29
 rk.msu.ac.th/wp-content/uploads/2017/09/14-Feixiang.pdf



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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] Aepyornithomimus tugrikinensis • First Ornithomimid (Theropoda, Ornithomimosauria) from the Upper Cretaceous Djadokhta Formation of Tögrögiin Shiree, Mongolia ---ScRaBBlE


Aepyornithomimus tugrikinensis
Tsogtbaatar, Kobayashi, Khishigjav, Currie, Watabe & Rinchen, 2017

Illustration by Masato Hattori

Abstract
The Upper Cretaceous Djadokhta Formation has been intensively surveyed for its fossil vertebrate fauna for nearly a century. Amongst other theropods, dromaeosaurids and parvicursorines are common in the formation, but ornithomimosaurs are extremely rare. A new ornithomimosaur material was discovered from the Djadokhta Formation, represented by eolian deposits, of the Tögrögiin Shiree locality, Mongolia. This is only the third ornithomimosaur specimen reported from this formation, and includes the astragalus, the calcaneum, the third distal tarsal, and a complete pes. The new material is clearly belonged to Ornithomimidae by its arctometatarsalian foot condition and has the following unique characters; unevenly developed pair of concavities of the third distal tarsal, curved contacts between the proximal ends of second and fourth metatarsals, the elongate fourth digit, and a laterally inclined medial condyle on phalanx IV-1. These diagnostic characters of the Djadokhtan ornithomimosaur indicate that this is a new taxon. Our phylogenetic analysis supports three clades within derived ornithomimosaurs, and the new taxon is placed a member of the derived ornithomimosaurs. The present specimen is the first ornithomimid record from eolian Tögrögiin Shiree locality, and is indicative of their capability to adapt to arid environments.



Systematic paleontology
Dinosauria Owen, 184224.
Theropoda Marsh, 188125.

Ornithomimosauria Barsbold, 197626.
Ornithomimidae Marsh, 189027.

Aepyornithomimus tugrikinensis gen. et sp. nov.

Etymology: The generic name refers to the largest ratite bird Aepyornis~, which has similar pes structure; in Latin, ~mimus = ‘as’ or ‘like’; the species name tugrikinensis refers to the locality where the specimen was found.

Holotype: MPC-D 100/130, articulated left pes preserved with an astragalus that is missing the ascending process, a complete calcaneum, and distal tarsal III (DT-III) (Figs 2, 3 and 4). The original specimen is now housed in the Institute of Paleontology and Geology of the Mongolian Academy of Sciences (IPG-MAS).


Type locality and horizon: Central Sayr of Tögrögiin Shiree locality, Upper Cretaceous Djadokhta Formation (Campanian) (Fig. 1). This locality is interpreted as semi-arid eolian sediments28 with up to 52 m of light gray, cross-bedded, structureless sands and sandstones17.

Diagnosis: An ornithomimid dinosaur with the following unique characters; unevenly developed pair concavities on the posterior margin of the DT-III; robust distal articular caput of second metatarsal (Mt II) in dorsal view; proximoventrally rounded ridge of phalanx II-1 (II-1); the elongate fourth digit; laterally inclined medial condyle of phalanx IV-1 (IV-1); elongated pedal unguals.

Illustration by Masato Hattori 

Figure 8: Comparative graph and restoration drawing of Aepyornithomimus tugrikinensis.
 (a), Different proportions of the three metatarsals is represented by ternary diagram, (b), Illustration is drawn by Mr. Masato Hattori.
Abbreviations: (Mt II), the metatarsal II, (Mt III), the metatarsal III, and (Mt III), the metatarsal III, (Ω), Aepyornithomimus tugrikinensis, (Δ), basal ornithomimosaurs, (Π), deinocheirids, (†), ornithomimids. 

Chinzorig Tsogtbaatar, Yoshitsugu Kobayashi, Tsogtbaatar Khishigjav, Philip J. Currie, Mahito Watabe and Barsbold Rinchen. 2017. First Ornithomimid (Theropoda, Ornithomimosauria) from the Upper Cretaceous Djadokhta Formation of Tögrögiin Shiree, Mongolia.  Scientific Reports. 7, Article number: 5835. DOI:  10.1038/s41598-017-05272-6
  
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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.

[PaleoMammalogy • 2018] Miopetaurista neogrivensis • Oldest Skeleton of A Fossil Flying Squirrel Casts New Light on the Phylogeny of the Group ---ScRaBBlE


Miopetaurista neogrivensis Mein 1970

in Casanovas-Vilar, Garcia-Porta, Fortuny, et al., 2018. 

Abstract
Flying squirrels are the only group of gliding mammals with a remarkable diversity and wide geographical range. However, their evolutionary story is not well known. Thus far, identification of extinct flying squirrels has been exclusively based on dental features, which, contrary to certain postcranial characters, are not unique to them. Therefore, fossils attributed to this clade may indeed belong to other squirrel groups. Here we report the oldest fossil skeleton of a flying squirrel (11.6 Ma) that displays the gliding-related diagnostic features shared by extant forms and allows for a recalibration of the divergence time between tree and flying squirrels. Our phylogenetic analyses combining morphological and molecular data generally support older dates than previous molecular estimates (~23 Ma), being congruent with the inclusion of some of the earliest fossils (~36 Ma) into this clade. They also show that flying squirrels experienced little morphological change for almost 12 million years.

Fig 1: The fossil flying squirrel Miopetaurista neogrivensis.
 (a) Reconstruction of the skeleton based in the partial skeleton IPS56468 from Abocador de Can Mata. Missing elements are based on extant giant flying squirrel Petaurista petaurista and are colored in blue.
(b) Life appearance of Miopetaurista neogrivensis showing the animal ready to land on a tree branch. Coat pattern and color are based in extant Petaurista species, the sister taxon of Miopetaurista.  Scale bar is 4 cm.


Fig 3: Mandible and cheek teeth of Miopetaurista neogrivensis.
 (a to c) Partial left hemimandible (IPS56468j) in lateral, medial and dorsal views. (d to e) Partial right hemimandible (IPS56468i) in lateral and medial views. A caudal vertebra and a bone fragment are attached to the lateral side of the mandibular ramus. Both hemimandibles were associated to the partial skeleton IPS56468 from ACM/C5-D1. (f to g) Partial hemimandible (IPS87560) from ACM/C8-B sector in lateral and medial views. (h) Left upper cheek teeth series (P3–M3) of IPS56468h (Figure 6—Figure supplement 1 ). (i) Left lower cheek teeth series (p4–m3) of IPS56468j. Cheek teeth measurements are given in Supplementary file 4 whereas mandibular measurements are given in Supplementary file 6. For a detailed description and comparisons of cheek teeth and mandible morphology see Appendix 3.1 and 3.2. an, angular process; ar, articular process; co, coronoid process. Scale bar is 1 cm in figs. a to g; 2 mm in (h to i).

Fig 7: Flying squirrel phylogeny and node dating estimates based on a Bayesian total evidence analysis including Miopetaurista neogrivensis.


Fig 8: Fossil record of ‘flying squirrels’ and paleoclimatic data. Temporal ranges of purported flying squirrel genera in Europe, Asia and North America. The 95% highest posterior density (HPD) intervals for flying squirrel divergence as derived from total evidence and node dating analyses are indicated in orange shading (see Figure 7 and Figure 7—figure supplement 1 ). Darker shading indicates the time interval where both independently calculated estimates overlap, thus defining the most likely time interval for flying squirrel divergence. Global paleoclimatic data are taken from Zachos et al., 2001.


Conclusions: 
Miopetaurista neogrivensis is the oldest unquestionable flying squirrel and dates back to the middle/late Miocene boundary (11.6 Ma). Its diagnostic wrist anatomy indicates that the two subtribes of flying squirrels had already diverged at that time. Moreover, this new fossil allows for a recalibration of flying squirrel time of origin and diversification, generally providing somewhat older estimates than previous molecular analyses. These differ according to the phylogenetic method used, total evidence analysis estimates an interval of 36.6 – 24.9 Ma while node dating results in a younger estimate of 30.6 – 17.4 Ma. Therefore, we cannot rule out that at least some of the oldest (ca. 36 Ma) fossils tentatively identified as flying squirrels may indeed belong to this group. However, the estimates of both independent phylogenetic approaches overlap for the late Oligocene (31 – 25 Ma), which should be considered the most likely interval for flying squirrel divergence. The two flying squirrel subtribes are found to have diverged during the early Miocene (22 – 18 Ma) while most extant genera would do so during the Miocene, although they are not recorded until the Pleistocene. Miopetaurista neogrivensis is estimated to have diverged from Petaurista spp., its sister taxon, between 18.8 – 12.4 Ma, the oldest boundary overlapping with the earliest record of the genus Miopetaurista (18 – 17 Ma). Perhaps not surprisingly, the skeletons of both genera show little differences. Sciurids are often regarded as a morphologically conservative group and flying squirrels are no exception having experienced few morphological changes for almost 12 million years.


Isaac Casanovas-Vilar, Joan Garcia-Porta, Josep Fortuny, Óscar Sanisidro, Jérôme Prieto, Marina Querejeta, Sergio Llácer, Josep M Robles, Federico Bernardini, and David M Alba. 2018. Oldest Skeleton of A Fossil Flying Squirrel Casts New Light on the Phylogeny of the Group.  eLife. 7; e39270 DOI:  10.7554/eLife.39270.001

Oldest fossil of a flying squirrel sheds new light on its evolutionary tree
bit.ly/2Eaqv3f via @elife @EurekAlert

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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] Large-sized Theropod Spinosaurus: An Important Component of the Carnivorous Dinosaur Fauna in southern Continents During the Cretaceous ---ScRaBBlE


Semi-aquatic paleoenvironmental reconstruction of Spinosaurus dinosaur during early Late Cretaceous:
 (A) 
Spinosaurus; (B) Mawsonia coelacanth fishes

in Candeiro, Gil & de Castro, 2018. 
 (drawing Luciano Vidal)

Abstract 
The Early Cretaceous of North Africa has Spinosaurinae dinosaur remains such as Spinosaurus recorded in Algeria (Guir Basin, Kem Kem beds), Egypt (Bahariya Formation), Morocco (Kem Kem beds), and Tunisia (Ain El Guettar Formation). Until now, three possible Spinosaurus species were identified: Spinosaurus aegyptiacus, Spinosaurus sp. and Spinosaurus “B”. The occurrence of this genus in the Albian-Cenomanian rocks of Africa suggests that the temporal and geographic distribution of these spinosaurines is the largest one among all genera and species of megapredators from the middle Cretaceous of Africa. The fossil record of Spinosaurus from the Albian to the Cenomanian shows a 20 million year persistence of this genus in Gondwanan ecosystems.

Keywords: theropod dinosaur, distribution, Early Cretaceous, Africa


Fig. 3 Most complete Spinosaurus species skulls from early Late Cretaceous formations from Northern Africa.
 Spinosaurus aegyptiacus (from Stromer, 1915), BSP 1912 – dentary, A in lateral and B in dorsal views.
Spinosaurus cf. aegyptiacus (from Buffetaut and Ouaja, 2002), BM231 – rostral part of left dentary, C, in lateral and in D dorsal views.
 Spinosaurus marrocanus (nomen dubium) (Taquet and Russell, 1998) MNHM SAM 124 – left maxilary, E in lateral and F dorsal views.
Spinosaurus cf. S. aegyptiacus (from Dal Sasso et al., 2005) MSNM V4047 – left maxilary, G in lateral in dorsal view.

Fig. 5. Semi-aquatic paleoenvironmental reconstruction of Spinosaurus dinosaur during early Late Cretaceous: (A) Spinosaurus; (B) Mawsonia coelacanth fishes; (C) Araripemys turtle (drawing Luciano Vidal).

 Remarks: 
The middle Cretaceous strata of North Africa preserved an important record of the theropod Spinosaurus. Although their fossil remains are usually fragmented, most specimens show diagnostic characters of the genus Spinosaurus that are especially present in their conical and non-serrated teeth. The fossil record of this genus in North Africa shows a restricted geographic distribution between the Albian and the Cenomanian periods. Yet, when we consider their temporal distribution, it suggests that Spinosaurus had a significant geological history of nearly 20 million years, a lifespan unknown for other African megapredators species (e.g., Carcharodontosaurus – 18.5 mya [Candeiro et al., 2018]). The geological evidences indicate that Africa was an island during the main period of occurrence of this genus. The faunal composition of the spinosaurinae that inhabited the eastern coast of Africa is broadly comparable with the Cenomanian fossil records from western Africa, supporting the relative homogeneous composition of the taxon in these areas during this period. Additional studies and future field prospections in other localities could eventually reveal a wider distribution of this genus in other regions of Africa (e.g., Niger, Sudan) or even in western Europe and northern South America.


Carlos Roberto A. Candeiro, Lívia Motta Gil and Pedro Ernesto Pontes de Castro. 2018. Large-sized Theropod Spinosaurus: An Important Component of the Carnivorous Dinosaur Fauna in southern Continents During the Cretaceous. Bulletin de la Société Géologique de France. 189 (4-6): 15.  DOI: 10.1051/bsgf/2018010


Résumé – Spinosaurus (théropode de grande taille) : une composante importante de la faune de dinosaures carnivores des continents méridionaux au cours du Crétacé. Le Crétacé inférieur d’Afrique du Nord renferme des restes de dinosaures spinosaurinés, tels que Spinosaurus répertorié en Algérie (Bassin du Guir, Kem Kem beds), en Égypte (Formation Bahariya), au Maroc (Kem Kem beds) et en Tunisie (Formation Ain El Guettar). Jusqu’à ce jour, trois espèces de spinosaure sont reconnues : Spinosaurus aegyptiacus, Spinosaurus sp. et Spinosaurus “B”. La présence de ce genre dans les terrains albocénomaniens d’Afrique suggère que la répartition temporelle et géographique de ces spinosaurinés est la plus étendue de tous les genres et espèces de méga-prédateurs du Crétacé moyen d’Afrique. Le registre fossile de Spinosaurus, depuis l’Albien jusqu’au Cénomanien, indique une présence de 20 millions d’années pour ce genre dans les écosystèmes gondwaniens. 
Mots clés : théropode dinosaure / distribution / Crétacé inférieur / Afrique

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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] Bagualosaurus agudoensis • A New Dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Brazil Provides Insights on the Evolution of Sauropodomorph Body Plan ---ScRaBBlE


Bagualosaurus agudoensis
Pretto, Langer & Schultz, 2018

Illustration: Jorge Blanco  coral.ufsm.br

Abstract
A new sauropodomorph dinosaur from the Late Triassic Candelária Sequence (Santa Maria Formation), south Brazil, Bagualosaurus agudoensis gen. et sp. nov., helps to fill a morphological gap between the previously known Carnian members of the group and younger sauropodomorphs. In some aspects, the skull, lower jaw, and dental anatomy of the new taxon approaches that seen in Norian forms like Pantydraco caducus, Efraasia minor, and Plateosaurus engelhardti. On the contrary, the post-cranial skeleton is broadly reminiscent of coeval, early dinosaurs. Although not reaching the size of most Norian and younger sauropodomorphs, B. agudoensis is significantly larger than coeval forms. The new data thus suggest that modifications in skull anatomy, possibly related to more efficient herbivorous habits, appeared early in sauropodomorph evolution, along with a moderate increase in size, followed in post-Carnian times by further increase in size, accompanied by more radical changes in post-cranial anatomy.

Keywords: Candelária Sequence, Early dinosaurs, Late Triassic, Santa Maria Formation, Sauropodomorpha






SYSTEMATIC PALEONTOLOGY 

Dinosauria Owen, 1842 sensu Padian & May, 1993 
Saurischia Seeley, 1887 sensu Gauthier, 1986 
Sauropodomorpha von Huene, 1932 

Bagualosaurus agudoensis gen. et sp. nov.

Etymology The generic name is derived from the term ‘Bagual’, a term employed regionally in southern Brazil to refer to an animal or person of strong build or valour, plus ‘saurus’, Latin, meaning lizard; the specific name makes allusion to the town of Agudo, where the holotype was collected.

....

CONCLUSION: 
Bagualosaurus agudoensis represents the largest known Carnian sauropodomorph. Indeed, if the material described by Pretto et al. (2015) is regarded as a second specimen of the taxon, its body size would rival that of many other Carnian taxa (e.g. rhynchosaurs and cynodonts, at least from Brazilian faunas). Despite that, B. agudoensis is far from achieving the large body sizes of most post-Carnian sauropodomorphs. Indeed, most traits related to large body masses (such as robust hindlimbs, especially the pes) are not yet present in B. agudoensis, and most traits shared with post-Carnian sauropodomorphs seem to be related to the skull and mandible. This suggests that modification in the skull anatomy, possibly related to more efficient herbivorous habits, appeared earlier in the evolution of sauropodomorphs than their further increase in size. The discovery of Bagualosaurus agudoensis adds to the known dinosaur diversity of the Carnian. It also reinforces the idea that sauropodomorphs had an initial moment of high diversification, prior to their increase in abundance achieved during the Norian and afterwards when the group started to represent a dominant component of many paleoenvironments (Brusatte et al., 2010; Ezcurra, 2010; Langer et al., 2010; Irmis, 2011).


Representação artística da paisagem na região de Agudo no período Triássico. No centro da imagem, uma dupla de Bagualosaurus agudoensis confronta o cinodonte Trucidocynodon riograndensis . No canto inferior direito, um Hyperodapedon, réptil herbívoro do grupo dos rincossauros. Ao fundo, um grupo de cinodontes, Exaeretodon riograndensis, observa a cena.
Arte: Jorge Blanco

Flávio A. Pretto, Max C. Langer and Cesar L. Schultz. 2018. A New Dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Brazil Provides Insights on the Evolution of Sauropodomorph Body Plan.  Zoological Journal of the Linnean Society. zly028.  DOI: 10.1093/zoolinnean/zly028

“Tataravô” de gigantes  coral.ufsm.br/arco/sitenovo/?p=3670  
Estudo põe mais um dinossauro na pré-história do País @estadao:   brasil.estadao.com.br/noticias/geral,estudo-poe-mais-um-dinossauro-na-pre-historia-do-pais,70002323449

   

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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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