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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 Cretaceous. Show all posts
Showing posts with label Cretaceous. Show all posts

Wednesday, March 20, 2019

[Paleontology • 2018] Diluvicursor pickeringi • A New Small-bodied Ornithopod (Dinosauria, Ornithischia) from A Deep, High-energy Early Cretaceous River of the Australian–Antarctic Rift System ---ScRaBBlE


Diluvicursor pickeringi
Herne​, Tait, Weisbecker, Hall, Nair, Cleeland & Salisbury, 2018

Artwork by P. Trusler.  DOI: 10.7717/peerj.4113 

Abstract

A new small-bodied ornithopod dinosaurDiluvicursor pickeringi, gen. et sp. nov., is named from the lower Albian of the Eumeralla Formation in southeastern Australia and helps shed new light on the anatomy and diversity of Gondwanan ornithopods. Comprising an almost complete tail and partial lower right hindlimb, the holotype (NMV P221080) was deposited as a carcass or body-part in a log-filled scour near the base of a deep, high-energy river that incised a faunally rich, substantially forested riverine floodplain within the Australian–Antarctic rift graben. The deposit is termed the ‘Eric the Red West Sandstone.’ The holotype, interpreted as an older juvenile ∼1.2 m in total length, appears to have endured antemortem trauma to the pes. A referred, isolated posterior caudal vertebra (NMV P229456) from the holotype locality, suggests D. pickeringi grew to at least 2.3 m in length. D. pickeringi is characterised by 10 potential autapomorphies, among which dorsoventrally low neural arches and transversely broad caudal ribs on the anterior-most caudal vertebrae are a visually defining combination of features. These features suggest D. pickeringi had robust anterior caudal musculature and strong locomotor abilities. Another isolated anterior caudal vertebra (NMV P228342) from the same deposit, suggests that the fossil assemblage hosts at least two ornithopod taxa. D. pickeringi and two stratigraphically younger, indeterminate Eumeralla Formation ornithopods from Dinosaur Cove, NMV P185992/P185993 and NMV P186047, are closely related. However, the tail of D. pickeringi is far shorter than that of NMV P185992/P185993 and its pes more robust than that of NMV P186047. Preliminary cladistic analysis, utilising three existing datasets, failed to resolve D. pickeringi beyond a large polytomy of Ornithopoda. However, qualitative assessment of shared anatomical features suggest that the Eumeralla Formation ornithopods, South American Anabisetia saldiviai and Gasparinisaura cincosaltensis, Afro-Laurasian dryosaurids and possibly Antarctic Morrosaurus antarcticus share a close phylogenetic progenitor. Future phylogenetic analysis with improved data on Australian ornithopods will help to test these suggested affinities.

Systematic Palaeontology
ORNITHISCHIA Seeley, 1888
CERAPODA Sereno, 1986
ORNITHOPODA Marsh, 1881



Figure 6: Partial postcranium, NMV P221080, assigned to the holotype of Diluvicursor pickeringi gen. et sp. nov., as prepared on five blocks of ETRW Sandstone. (A) Specimen viewed from above, normal to the bedding. (B) Schematic.

Abbreviations: as, astragalus; B #, host block number; Ca #, designated caudal vertebra and position; cal, calcaneum; fib, fibula; ha #, haemal arch/process and position; pd #, pedal digit number; tib, tibia. Image of NMV P221080, courtesy S. Poropat and Museums Victoria.

Figure 7: Diluvicursor pickeringi gen. et sp. nov. holotype (NMV P221080), schematic restoration in left lateral view, showing preserved bones (light shading) and incomplete caudal vertebrae (outlined). 

Abbreviations: as, astragalus; Ca #, designated caudal vertebral position; pd #, pedal digit number; tib, tibia.

Diluvicursor gen. nov.  

Etymology: From the Latin ‘diluvi,’ for deluge or flood, in reference to the deep high-energy palaeo-river within which the type material was deposited and the palaeo-floodplain upon which the river extended, combined with the suffix ‘-cursor,’ from the Latin for runner.

Diagnosis: A turkey- to rhea-sized small-bodied ornithopod, differentiated from all other ornithopods by 10 potential autapomorphies: (1) dorsoventral height of the neural arch on the anterior-most caudal vertebrae (indicated at Ca 3), highly reduced and sub-equal to dorsoventral centrum height; (2) proximodistal length of the spinal process on the anterior caudal vertebrae (Ca 3–6), highly reduced and sub-equal to anteroposterior centrum length; (3) prezygapophysis on the anterior-most caudal vertebrae (up to Ca 5), horizontally oriented and located at the neural arch base, lateral to the neural canal; (4) tuberous process dorsally on the spinoprezygapophyseal lamina (sprl) of the anterior-most caudal vertebrae; (5) dorsoventrally narrowest part of the centrum on the posterior caudal vertebrae, distinctly offset posteriorly and embayed by a sulcus; (6) deep haemal groove present on all posterior caudal vertebrae; (7) triangular intervertebral process anteriorly on the centrum of the posterior-most caudal vertebrae incises a V-shaped notch at the posterior end of the adjoining centrum; (8) caudal ribs on the anterior-most caudal vertebrae (indicated at Ca 3) are transversely broad with the distance across the ribs ∼85% of total vertebral height (inclusive of haemal arch); (9) lateral distal tarsal embayed anteriorly by a sulcus for the calcaneum; and (10) pd IV-1 is strongly asymmetrical in dorsoplantar view (the proximal cotyle flares medially and the lateral edge is straight).


Diluvicursor pickeringi sp. nov.   
2009 Ornithopoda; Rich et al., p. 677.
2014 Ornithopoda; Herne, pp. 246–274.

Derivation of name: To acknowledge the significant contribution of David A. Pickering to Australian palaeontology and in memory of his passing during the production of this work.

Distribution: Lower Cretaceous Australia.

Locality: Eric the Red West, ETRW Sandstone, lower Albian, Eumeralla Formation, Otway Group, southern Victoria.

Figure 36: Artist’s interpretation of the early Albian, volcaniclastic, floodplain palaeoenvironment within the Australian-Antarctic rift graben, in the region of Eric the Red West.
Scene depicting two individuals of Diluvicursor pickeringi on the cutbank of a high-energy meandering river, regional floral components and distant rift margin uplands. Floral components potentially included forest trees of Araucariaceae (Agathis and Araucaria), Podocarpaceae and Cupressaceae and lower story/ground cover plants, including pteridophytes (ferns, including equisetaleans), hepatics, lycopods, cycadophytes, bennettitaleans, seed-bearing fern- or cycad-like taeniopterids and early Australian angiosperms.
 Artwork by P. Trusler.

Conclusion
Diluvicursor pickeringi nov. gen. et sp. is a new small-bodied ornithopod from the lower Albian of the Eumeralla Formation in the Otway Basin. The taxon is known from an almost complete tail and lower partial right limb of the holotype (NMV P221080), as well as an isolated posterior caudal vertebra (NMV P229456), discovered at the fossil locality of Eric the Red West (ETRW). The deposit, termed the ETRW Sandstone, is interpreted to have been a broad (∼600 m), deep (∼25 m), high-energy meandering river. Sediments and fossils from the ETRW Sandstone indicate that D. pickeringi inhabited a faunally rich, substantially forested riverine floodplain within the Australian–Antarctic rift complex. A further isolated caudal vertebra from the deposit (NMV P228342), interpreted as that of an indeterminate ornithischian, suggests the locality may have hosted at least two small-bodied ornithischians. D. pickeringi grew to at least 2.3 m in length and is characterised by 10 potential autapomorphies, among which, the combination of dorsoventrally low neural arches and transversely broad caudal ribs on the anterior-most caudal vertebrae present a visually defining combination of features.

Features of the caudal vertebrae and pes suggest that D. pickeringi and the two stratigraphically younger, indeterminate ornithopods from Dinosaur Cove, NMV P185992/P185993 and NMV P186047, are closely related. However, D. pickeringi differs from NMV P185992/P185993 by having a far shorter tail (50 vertebrae compared to >71) and from NMV P186047 by having a comparatively shorter, more robust, pes. The phylogenetic position of D. pickeringi investigated through searches within three recently published datasets was unresolved beyond placement within a polytomous clade of non-iguanodontian ornithopods. Various features of the caudal vertebrae and pes suggest that the Eumeralla Formation ornithopods Diluvicursor, NMV P185992/P185993 and NMV P186047 may be more closely related to the Argentinean ornithopods Anabisetia and Gasparinisaura, the Antarctic ornithopod Morrosaurus and possibly Afro-Laurasian dryosaurids, than all other ornithopods. A common progenitor of these taxa is suggested. However, these suggested affinities are to be tested more rigorously within a revised cladistic dataset of Gondwanan ornithopods.

The discovery of D. pickeringi in the ETRW Sandstone indicates that future prospecting efforts in the Eumeralla Formation at locations where coarse, gritty sediments crop-out at the base of deep palaeoriver channels, could lead to significant new discoveries (see also Rich et al., 2009b). The articulated postcrania of similarly sized, but anatomically differing small-bodied ornithopods from the Eumeralla Formation provide unique fossil material for future comparative investigations on dinosaur biomechanics, and how differing locomotor abilities could relate to differing palaeoecosystems.


Matthew C. Herne​, Alan M. Tait, Vera Weisbecker, Michael Hall, Jay P. Nair, Michael Cleeland and Steven W. Salisbury. 2018. A New Small-bodied Ornithopod (Dinosauria, Ornithischia) from A Deep, High-energy Early Cretaceous River of the Australian–Antarctic Rift System.  PeerJ. 5:e4113.  DOI: 10.7717/peerj.4113

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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] Sibirotitan astrosacralis • A New Sauropod dinosaur from the Lower Cretaceous Ilek Formation, Western Siberia, Russia ---ScRaBBlE


Sibirotitan astrosacralis
Averianov, Ivantsov, Skutschas, Faingertz & Leshchinskiy, 2018

Сибиротитан звездокрестцовый  DOI: 10.1016/j.geobios.2017.12.004

Abstract
Sibirotitan astrosacralis nov. gen., nov. sp., is described based on isolated but possibly associated cervical and dorsal vertebrae, sacrum, and previously published pedal elements from the Lower Cretaceous (Barremian?) Ilek Formation at Shestakovo 1 locality (Kemerovo Province, Western Siberia, Russia). Some isolated sauropod teeth from the Shestakovo 1 locality are referred to the same taxon. The phylogenetic parsimony analyses place Sibirotitan astrosacralis nov. gen., nov. sp., as a non-titanosaurian somphospondyl titanosauriform. The new taxon exhibits four titanosauriform and one somphospondylan synapomorphies, and one autapomorphy – a hyposphene ridge that extends between the neural canal and the postzygapophyses. It differs from all other Somphospondyli by having only five sacral vertebrae. The new taxon shares with Euhelopus and Epachtosaurus sacral ribs that converge towards the middle of the sacrum in dorsal view. Sibirotitan astrosacralis nov. gen., nov. sp., is only the second sauropod taxon from Russia and one of the oldest titanosauriform described so far in Asia.

Keywords: Sibirotitan astrosacralis nov. gen., nov. sp.; Titanosauriformes; Sauropoda; Phylogenetic parsimony analysis; Early Cretaceous; Siberia; Asia



Dinosauria Owen, 1842
Saurischia Seeley, 1887

Sauropoda Marsh, 1878
Titanosauriformes Salgado et al., 1997

Genus Sibirotitan nov. gen.

Derivation of the name: from Siberia and Greek Tιτάν (titan), a member of the second order of divine beings, descended from the primordial deities and preceding the Olympian deities in Greek mythology.

Type and only species: Sibirotitan astrosacralis nov. gen., nov. sp.

Derivation of the name: from Greek αστρον (star) and Latin os sacrum (“sacred bone”), an allusion to the unusual configuration of sacral ribs which radiate, in dorsal view, from the middle of the sacrum as the rays of a star.


 S.V. Ivantsov digging out the posterior cervical vertebra PM TGU 120/8-Sh1-3 from the Malyi Yar outcrop in 2008 (Kemerovo Province, Russia). Photo by S.V. Leshchinskiy.

  

  


 Alexander Averianov, Stepan Ivantsov, Pavel Skutschas, Alexey Faingertz and Sergey Leshchinskiy. 2018. A New Sauropod dinosaur from the Lower Cretaceous Ilek Formation, Western Siberia, Russia. Geobios. In Press.  DOI: 10.1016/j.geobios.2017.12.004



Averianov, A.O., Voronkevich, A.V., Maschenko, E.N., Leshchinskiy, S.V., and Fayngertz, A.V. 2002. A sauropod foot from the Early Cretaceous of Western Siberia, Russia. Acta Palaeontologica Polonica. 47 (1): 117–124.  DOI: 10.1.1.492.1575 


Познакомьтесь с новым сибирским динозавром https://metkere.com/2018/01/sibirotitan.html via @metkere
Новый род найденных в Кузбассе динозавров назвали сибиротитаном https://mediakuzbass.ru/news/obshhestvo/94522.html 


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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 | Ichnotaxa • 2018] Gigandipus chiappei • Theropod Assemblages and A New Ichnotaxon from the Jiaguan Formation, Lower Cretaceous of Guizhou Province, China ---ScRaBBlE


Gigandipus chiappei
Xing, Lockley, Klein, Zeng, Cai, Luo & Li, 2018


Highlights
1. First example of a Cretaceous track morphotype attributable to Gigandipus.
2. Second report largest avian theropod tracks Wupus from Lower Cretaceous.
3. The similarity between K1 and J1 theropod ichnotaxa in East Asia.

Abstract
A newly discovered Jiaguan Formation (Lower Cretaceous) tracksite from the Linjiang region of Guizhou Province, China, reveals the first example of a Cretaceous track morphotype attributable to the non-avian theropod ichnogenus Gigandipus, here named Gigandipus chiappei ichnosp nov. The theropod dominated locality also reveals the second report of the avian theropod ichnogenus Wupus, one of the largest avian traces currently known from the Lower Cretaceous. The Linjiang site provides evidence to support previous interpretations of a distinctive Lower Cretaceous theropod-dominated ichnofauna that was widespread in China and East Asia and highlights the similarity between Lower Cretaceous theropod ichnotaxa in East Asia and those found in the Lower Jurassic both in East Asia and elsewhere. These similarities in turn create various ichnotaxonomic challenges familiar to researchers working on theropod tracks, and we recommend caution in the naming of new theropod ichnotaxa at the ichnogenus level.

Keywords: Early Cretaceous; Jiaguan Formation; theropod tracks; Gigandipus; Wupus




 Gigandipus tracks

Theropoda Marsh, 1881
Gigandipodidae Lull, 1904

Gigandipus Hitchcock, 1856; Lull, 1904
Type ichnospecies G. caudatus Lull, 1904

Gigandipus chiappei ichnosp. nov.

Etymology. The specific name is in honor of Dr. Luis M. Chiappe, a distinguished paleontologist who is world-renowned on the origin and early evolution birds.

....


 Conclusions 
The Linjiang tracksite in the Jiaguan Formation of Guizhou Province reveals the first example of a Cretaceous track morphotype attributable to the non-avian theropod ichnogenus Gigandipus, here named G. chiappei ichnosp nov. The site also reveals only the second report of the avian theropod ichnogenus Wupus, which is one of the largest avian traces currently known from the Lower Cretaceous. The discovery underscores the importance of the Jiaguan Formation as a major source of tetrapod (theropod) data in the Sichuan Basin region from which little or no useful body fossil data have been recovered.
 Data from the Linjiang site provide growing support for a distinctive and widespread Lower Cretaceous theropod-dominated ichnofauna in China. This ichnofauna also shows notable similarities to other Lower Cretaceous theropod dominated ichnofaunas from East Asia, notably Korea. There are also taxonomically challenging similarities between these Lower Cretaceous ichnofaunas and those found in the Lower Jurassic both in East Asia and elsewhere. These challenges, which raise perennial “lumper-splitter” debates, suggest ichnologists should exercise caution naming new ichnotaxa, especially at the ichnogenus level.  


Lida Xing, Martin G. Lockley, Hendrik Klein, Rong Zeng, Sifu Cai, Xiuchun Luo and Chen Li. 2018. Theropod Assemblages and A New Ichnotaxon Gigandipus chiappei ichnosp. nov. from the Jiaguan Formation, Lower Cretaceous of Guizhou Province, China. Geoscience Frontiers. In Press. DOI: 10.1016/j.gsf.2017.12.012

  

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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] Osteology of the Late Cretaceous Argentinean Sauropod Dinosaur Mendozasaurus neguyelap: Implications for Basal Titanosaur Relationships ---ScRaBBlE


Mendozasaurus neguyelap Gonzàlez Riga, 2003

in Gonzàlez Riga, Mannion, Poropat, David & Coria. 2018. 

Abstract
The titanosaurian sauropod dinosaur Mendozasaurus neguyelap is represented by several partial skeletons from a single locality within the Coniacian (lower Upper Cretaceous) Sierra Barrosa Formation in the south of Mendoza Province, northern Neuquén Basin, Argentina. A detailed revision of Mendozasaurus, including previously undocumented remains from the holotype site, allows us to more firmly establish its position within Titanosauria, as well as enabling an emended diagnosis of this taxon. Autapomorphies include: (1) middle and posterior cervical vertebrae with tall and transversely expanded neural spines that are wider than the centra, formed laterally by spinodiapophyseal laminae that are not connected with the pre- or postzygapophyses; (2) anterior caudal vertebrae (excluding anteriormost) with ventrolateral ridge-like expansion of prezygapophyses; and (3) humerus with divided lateral distal condyle on anterior surface. New remains demonstrate that the presacral vertebrae of Mendozasaurus were not unusually short anteroposteriorly, with this compression instead resulting from taphonomic crushing. Comparative studies of articulated pedes of other taxa allow us to interpret that the pedal formula of Mendozasaurus was 2-2-2-2-0, based on disarticulated bones that form a right hind foot. Mendozasaurus was incorporated into an expanded version of a titanosauriform-focussed phylogenetic data matrix, along with several other contemporaneous South American titanosaurs. The resultant data matrix comprises 84 taxa scored for 423 characters, and our phylogenetic analysis recovers Mendozasaurus as the most basal member of a diverse Lognkosauria, including Futalognkosaurus and the gigantic titanosaurs Argentinosaurus, Notocolossus, Patagotitan and Puertasaurus. Lognkosauria forms a clade with Rinconsauria (Muyelensaurus + Rinconsaurus), with Epachthosaurus and Pitekunsaurus recovered at the base of this grouping. A basal lithostrotian position for this South American clade is well supported, contrasting with some analyses that have placed these taxa outside of Lithostrotia or closer to Saltasauridae. The sister clade to this South American group is composed of an array of near-global taxa and supports the hypothesis that most titanosaurian clades were widespread by the Early–middle Cretaceous.


Figure 3. Life restoration of Mendozasaurus neguyelap based on the largest adult individual (femur length: 1530 mm). Artwork by Bernardo Gonzaléz Riga.

  CONCLUSIONS
A detailed description of all remains pertaining to the early Late Cretaceous Argentinean titanosaurian sauropod dinosaur Mendozasaurus neguyelap enables a revised diagnosis for the genus. An expanded phylogenetic analysis recovers Mendozasaurus and several other taxa as part of a rich Lognkosauria that is placed within a diverse clade of South American lithostrotian titanosaurs. The sister clade to this South American group is composed of a near-global array of titanosaurs, which supports recent work that has argued for a widespread distribution of most titanosaurian clades by the Early–middle Cretaceous.


Bernardo J. Gonzàlez Riga, Philip D. Mannion, Stephen F. Poropat, Leonardo D. Ortiz David and  Juan Pedro Coria. 2018. Osteology of the Late Cretaceous Argentinean Sauropod Dinosaur Mendozasaurus neguyelap: Implications for Basal Titanosaur Relationships. Zoological Journal of the Linnean Society. zlx103.  DOI: 10.1093/zoolinnean/zlx103
Bernardo J. González Riga. 2003. A new titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Mendoza, Argentina. Amehginiana. 40: 155-172.


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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] Borealopelta markmitchelli • An Exceptionally Preserved Three-Dimensional Armored Dinosaur Reveals Insights into Coloration and Cretaceous Predator-Prey Dynamics ---ScRaBBlE


Borealopelta markmitchelli 
Brown, Henderson, Vinther, Fletcher, Sistiaga, Herrera & Summons, 2017


Highlights
• A new armored dinosaur is described based on an exceptionally preserved specimen
• Abundant in situ osteoderms with keratinous sheaths and scales are preserved
• Reddish-brown coloration and crypsis in the form of countershading are indicated
• Crypsis indicates strong predation pressure on this large, heavily armored dinosaur


Summary
Predator-prey dynamics are an important evolutionary driver of escalating predation mode and efficiency, and commensurate responses of prey. Among these strategies, camouflage is important for visual concealment, with countershading the most universally observed. Extant terrestrial herbivores free of significant predation pressure, due to large size or isolation, do not exhibit countershading. Modern predator-prey dynamics may not be directly applicable to those of the Mesozoic due to the dominance of very large, visually oriented theropod dinosaurs. Despite thyreophoran dinosaurs’ possessing extensive dermal armor, some of the most extreme examples of anti-predator structures, little direct evidence of predation on these and other dinosaur megaherbivores has been documented. Here we describe a new, exquisitely three-dimensionally preserved nodosaurid ankylosaur, Borealopelta markmitchelli gen. et sp. nov., from the Early Cretaceous of Alberta, which preserves integumentary structures as organic layers, including continuous fields of epidermal scales and intact horn sheaths capping the body armor. We identify melanin in the organic residues through mass spectroscopic analyses and observe lighter pigmentation of the large parascapular spines, consistent with display, and a pattern of countershading across the body. With an estimated body mass exceeding 1,300 kg, B. markmitchelli was much larger than modern terrestrial mammals that either are countershaded or experience significant predation pressure as adults. Presence of countershading suggests predation pressure strong enough to select for concealment in this megaherbivore despite possession of massive dorsal and lateral armor, illustrating a significant dichotomy between Mesozoic predator-prey dynamics and those of modern terrestrial systems.

 Systematic Paleontology

Dinosauria Owen, 1842  
Ornithischia Seeley, 1888  

Ankylosauria Osborn, 1923  
Nodosauridae Marsh, 1890  

Borealopelta markmitchelli gen. et sp. nov. 

Etymology: The generic name Borealopelta is derived from “borealis” (Latin, “northern”) and “pelta” (Greek, “shield”), in reference to the northern locality and the preserved epidermal scales and dermal osteoderms. The specific epithet markmitchelli honors Mark Mitchell for his more than 7,000 hours of patient and skilled preparation of the holotype.


An illustration of Borealopelta markmitchelli. The study suggests that it displayed a camouflage effect known as counter-shading.
 Illustration: Julius Csotonyi/Courtesy of the Royal Tyrrell Museum of Palaeontology, Canada. 


 Illustration: Robert Nicholls 


 Illustration: Davide Bonadonna











Figure 1. Photographs of the Holotype of Borealopelta markmitchelli, TMP 2011.033.0001 Top: anterodorsolateral view; bottom: anterodorsal view. Scale bar, 10 cm. 




Holotype: The holotype is Royal Tyrrell Museum of Palaeontology (TMP) 2011.033.0001: an articulated specimen preserving the head, neck, most of the trunk and sacrum, a complete right and a partial left forelimb and manus, partial pes (Figure 1). In situ osteoderms and nearly complete soft tissue integument are preserved across dorsal and lateral surfaces of the axial skeleton, posterodorsal surface of forelimbs, and plantar surfaces of a manus and a pes. Specimen is preserved in multiple large blocks, including slabs and counter-slabs in the sacral region.

Locality and Horizon: Suncor Millennium Mine, Fort McMurray, Alberta, Canada. Wabiskaw Member, Clearwater Formation, Aptian stage. Detailed locality data are available at Royal Tyrrell Museum of Palaeontology.

Diagnosis: A nodosaurid ankylosaur characterized by the following autapomorphies (∗) and suite of characters [character/state]: cranial: dorsal skull ornamentation expressed as a large hexagonal dermal plate in frontoparietal region and multiple (>20) small dermal plates in frontonasal region∗; external nares excluded from view dorsally (shared with Pawpawsaurus) [16:1]; supraorbital ornamentation forming sharp lateral rim dorsal to orbits (shared with Gargoyleosaurus and Kunbarrasaurus) [38:2]; jugal (suborbital) horn triangular with pointed apex (shared with GastoniaGargoyleosaurus, and Polocanthus); jugal (suborbital) horn base longer than orbit length∗; osteoderms: cervical and thoracic osteoderms form continuous (abutting) transverse rows completely separated by continuous transverse rows of polygonal basement scales; parascapular spine is the largest osteoderm, recurved, and projects posterolaterally and horizontally (potentially shared with Sauropelta); osteoderm count for transverse rows: cervicals: C1-3, C2-3, C3-3, transition: TR-2, thoracic: T1-6∗; third and sixth transverse thoracic osteoderm rows expressed medially but pinch out laterally∗.

The new taxon can be further differentiated from Pawpawsaurus based on: dermal plate in frontonasal region (central dermal plates) flat; absence of ciliary osteoderm. Can be further differentiated from Sauropelta based on: parietals flat to slightly convex; cervical half ring has 4–6 osteoderms only; medial cervical osteoderms subequal, hexagonal, and bear prominent median ridge with posterior margin projecting beyond the basal footprint.





Figure 2: Schematic Line Drawing of TMP 2011.033.0001, the Holotype of Borealopelta markmitchelli, Illustrating Preservation of the Different Tissue Types (A) Schematic of complete specimen in dorsal view. (B and C) Skull in dorsal (B) and left lateral (C) views. (D) Close-up view of the neck, illustrating alternating cervical osteoderm bands (and preserved keratinous sheaths) and polygonal scales. (E) Close-up view of flank illustrating lateral thoracic osteoderms (with keratinous coverings) and polygonal scales. (F) Close-up view of sacral shield counterpart illustrating osteoderms and scales. (G) Close-up view of antebrachium including osteoderms and keratinous coverings. (D’–G’) Interpretive line drawings of the corresponding panels (D)–(G). Scale bars in (B)–(G), 10 cm.

Figure 3Time-Calibrated Strict Consensus Tree Showing Position of Borealopelta markmitchelli within Ankylosauria, with Representative Well-Preserved Ankylosaurs Shown Above Bottom: time-calibrated strict consensus tree illustrating position of Borealopelta markmitchelli within Ankylosauria scaled to Jurassic and Cretaceous stages. Top: line drawings of representative well-preserved ankylosaur specimens with in situ armor and/or skin. Scale bars, 1 m.
(A) Kunbarrasaurus, QM F18101. (B) Euoplocephalus, NHMUK 5161. (C) Sauropelta, AMNH 3035 and 3036 composite. (D) Borealopelta, TMP 2011.033.0001 (this study). (E) Edmontonia, AMNH 5665.

Figure 4:  Chart Illustrating the Loss of Countershading as Body Mass Increases in Terrestrial Mammal Herbivores Chart includes pooled data for artiodactyls, perissodactyls, and proboscideans divided into body-mass bins, showing relative proportion of species that exhibit countershading. The diagonally hatched area represents the mass above which significant predation of adults does not occur. Animals illustrated above chart are representative taxa within each mass bin; species names in italics at top indicate body masses of the largest carnivores.

The Making of a Most Extraordinary Fossil

The Making of a Most Extraordinary Fossil

Caleb M. Brown, Donald M. Henderson, Jakob Vinther, Ian Fletcher, Ainara Sistiaga, Jorsua Herrera and Roger E. Summons. 2017. An Exceptionally Preserved Three-Dimensional Armored Dinosaur Reveals Insights into Coloration and Cretaceous Predator-Prey Dynamics. Current Biology. DOI: 10.1016/j.cub.2017.06.071


Despite heavy armor, new dinosaur used camouflage to hide from predators  eurekalert.org/e/7ZWJ via @CellPressNews @EurekAlert

It's Official: Stunning Fossil Is a New Dinosaur Species  on.natgeo.com/2vx0wxD via @NatGeo
This Is the Best Dinosaur Fossil of Its Kind Ever Found on.natgeo.com/2r02aW7 via @NatGeo
Discover How This Dinosaur Became an Extraordinary Fossil  NationalGeographic.com/magazine/2017/06/making-of-a-dinosaur-fossil-nodosaur-illustrations

Heavily armoured dinosaur had ginger camouflage to deter predators – study  theguardian.com/science/2017/aug/03/heavily-armoured-nodosaur-ginger-camouflage-predators-borealopelta-markmitchelli


ติดอยู่ในกาลเวลา  ngthai.com/animals/1703 via  เนชันแนล จีโอกราฟฟิก (National Geographic) ฉบับภาษาไทย

  

  


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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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