Search This Blog

مشاركة مميزة

[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...

Translate

Showing posts with label Royal Society Open Science. Show all posts
Showing posts with label Royal Society Open Science. Show all posts

Wednesday, March 20, 2019

[Paleontology • 2017] Zuul crurivastator • A New Ankylosaurine Dinosaur from the Judith River Formation of Montana, USA, Based On An Exceptional Skeleton with Soft Tissue Preservation ---ScRaBBlE


Zuul crurivastator 
 Arbour & Evans, 2017  

Abstract

The terrestrial Judith River Formation of northern Montana was deposited over an approximately 4 Myr interval during the Campanian (Late Cretaceous). Despite having been prospected and collected continuously by palaeontologists for over a century, few relatively complete dinosaur skeletons have been recovered from this unit to date. Here we describe a new genus and species of ankylosaurine dinosaur, Zuul crurivastator, from the Coal Ridge Member of the Judith River Formation, based on an exceptionally complete and well-preserved skeleton (ROM 75860). This is the first ankylosaurin skeleton known with a complete skull and tail club, and it is the most complete ankylosaurid ever found in North America. The presence of abundant soft tissue preservation across the skeleton, including in situ osteoderms, skin impressions and dark films that probably represent preserved keratin, make this exceptional skeleton an important reference for understanding the evolution of dermal and epidermal structures in this clade. Phylogenetic analysis recovers Zuul as an ankylosaurin ankylosaurid within a clade of Dyoplosaurus and Scolosaurus, with Euoplocephalus being more distantly related within Ankylosaurini. The occurrence of Z. crurivastator from the upper Judith River Formation fills a gap in the ankylosaurine stratigraphic and geographical record in North America, and further highlights that Campanian ankylosaurines were undergoing rapid evolution and stratigraphic succession of taxa as observed for Laramidian ceratopsids, hadrosaurids, pachycephalosaurids and tyrannosaurids.

KEYWORDS: Ornithischia, Thyreophora, Ankylosauria, Ankylosaurinae, Cretaceous, Campanian




Systematic palaeontology

Dinosauria Owen, 1842 
Ornithischia Seeley, 1887 
Thyreophora Nopcsa, 1915 

Ankylosauria Osborn, 1923 
Ankylosauridae Brown, 1908 
Ankylosaurinae Brown, 1908 
Ankylosaurini Arbour and Currie, 2016

ZUUL gen. nov.

Type and only known species: Zuul crurivastator gen. et sp. nov.

Etymology: The generic name refers to Zuul the Gatekeeper of Gozer, a fictional monster from the 1984 film Ghostbusters, and the species epithet, crurivastator, combines crus (Latin) for shin or shank, and vastator (Latin) for destroyer, in reference to the sledgehammer-like tail club.

Holotype: ROM 75860.

Diagnosis: Differs from all ankylosaurids in the possession of the following autapomorphies: imbricated, peaked frontonasal and frontoparietal caputegulae; prominent longitudinal furrows on the lateral surface of the squamosal horn; lateral caudal osteoderms along the tail club (excluding the knob osteoderms) are strongly concave on the leading edge with posteriorly offset apices; tail club knob dorsoventrally flat, with height to length ratio less than 0.20. Zuul can be further differentiated from other ankylosaurins in the following traits: possesses pyramidal prefrontal, frontoparietal and middle supraorbital caputegulae (unlike the conical caputegulae in Nodocephalosaurus and Talarurus); squamosal horns extend posteriorly well past the nuchal shelf, similar to Scolosaurus but unlike AnodontosaurusEuoplocephalus, or Ziapelta; postocular caputegulae small and sparsely distributed, similar to Scolosaurus but unlike AnodontosaurusEuoplocephalus or Ziapelta. Caudal osteoderms lateral to tail club handle are proportionately larger and more sharply pointed than in ankylosaurines from the Nemegt Formation of Mongolia.


Life restoration of Zuul crurivastator.
Illustration: Danielle Dufault 

Zuul crurivastator size compared to an African elephant Loxodonta africana.
Illustration: Danielle Dufault  

Holotype locality:
Approximately 5 km northwest of the John Wodarz Bridge, in badlands exposures of the Judith River Formation outcropping along the north side of the Milk River Drainage near the City of Havre, Montana (Section 35, Township 33N, Range 15E). GPS coordinates for the quarry are reposited at the Royal Ontario Museum. The site was originally designated Theropoda Exp LLC Locality LC02(Q).

Stratigraphic horizon and age: Coal Ridge Member of the Judith River Formation. The Coal Ridge Member was deposited between 76.2 and 75.2 Ma.


Figure 6. Overview of the tail of Zuul crurivastator ROM 75860 in dorsal view, with insets of detailed anatomy.
 (a) Field of ossicles in the anterior portion of the tail. (b) Detail of the neural arches of the handle caudal vertebrae, and ossified tendons. (c) Left caudal osteoderm from the seventh pair. (d) Preserved epidermal sheath on the right caudal osteoderm from the second pair. (e) Preserved epidermal sheath on the right caudal osteoderm from the third pair. (f) Epidermal scales lacking bony cores, arranged in a transverse row at the third pair of caudal osteoderms. (g) Close-up of the tail club knob. 


The knob of bone forming the sledgehammer-like tip of the tail in Zuul crurivastator.
photo: Brian Boyle/Royal Ontario Museum  

Conclusion: 
ROM 75860 represents a new ankylosaurine genus and species, Zuul crurivastator from the Judith River Formation. The holotype specimen is one of the most complete dinosaur skeletons from this formation, and is the first ankylosaurid skeleton described from this unit. Remarkably, ROM 75860 is the first ankylosaurin skeleton known with a complete skull and tail club, and it is the most complete ankylosaurid ever found in North America. The presence of abundant soft tissue preservation across the skeleton, including in situ osteoderms, skin impressions and dark films that probably represent preserved keratin, make this exceptional skeleton an important reference for understanding the evolution of dermal and epidermal structures in this clade. The recognition of Z. crurivastator from the Judith River Formation fills a gap in the ankylosaurine stratigraphic and geographical record and further highlights that Laramidian ankylosaurines were undergoing rapid evolutionary rates and stratigraphic turnover as observed for Laramidian ceratopsids, hadrosaurids, pachycephalosaurids and tyrannosaurids. The excellent preservation of ROM 75860 and the abundant diversity represented elsewhere in the same quarry highlight the potential for significant new fossil discoveries in the upper Judith River Formation and emphasize the need for continued work in this historically significant geological unit.

  
Victoria M. Arbour and David C. Evans. 2017. A New Ankylosaurine Dinosaur from the Judith River Formation of Montana, USA, Based On An Exceptional Skeleton with Soft Tissue Preservation. Royal Society Open Science. DOI: 10.1098/rsos.161086

Meet Zuul, destroyer of shins - the 75m-year-old 'Ghostbuster' dinosaur theguardian.com/science/2017/may/10/meet-zuul-destroyer-of-shins-the-75m-year-old-ghostbuster-dinosaur


---------------------------------------------------------------
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 • 2017] Dilophodelphis fordycei • A New Fossil Dolphin Provides Insight Into the Evolution of Supraorbital Crests in Platanistoidea (Mammalia, Cetacea) ---ScRaBBlE


Dilophodelphis fordycei
Boersma, McCurry & Pyenson, 2017 

  DOI: 10.1098/rsos.170022 
Image: A. Boersma  @Boersma_Alex 

Abstract

Many odontocete groups have developed enlarged facial crests, although these crests differ in topography, composition and function. The most elaborate crests occur in the South Asian river dolphin (Platanista gangetica), in which they rise dorsally as delicate, pneumatized wings anterior of the facial bones. Their position wrapping around the melon suggests their involvement in sound propagation for echolocation. To better understand the origin of crests in this lineage, we examined facial crests among fossil and living Platanistoidea, including a new taxonDilophodelphis fordyceinov. gen. and sp., described herein, from the Early Miocene Astoria Formation of Oregon, USA. We measured the physical extent and thickness of platanistoid crests, categorized their relative position and used computed tomography scans to examine their internal morphology and relative bone density. Integrating these traits in a phylogenetic context, we determined that the onset of crest elaboration or enlargement and the evolution of crest pneumatization among the platanistoids were separate events, with crest enlargement beginning in the Oligocene. However, we find no evidence for pneumatization until possibly the Early Miocene, although certainly by the Middle Miocene. Such an evolutionary context, including data from the fossil record, should inform modelling efforts that seek to understand the diversity of sound generation morphology in Odontoceti.

KEYWORDS: cetacean, Platanistoidea, river dolphins, Miocene, pneumatization, computed tomography

Systematic palaeontology

Cetacea Brisson, 1762 
Odontoceti Flower, 1867 sensu Fordyce and Muizon, 2001 

Platanistoidea sensu Boersma and Pyenson 2016 
Platanistidae Gray, 1846  sensu Boersma and Pyenson 2016 

Dilophodelphis, gen. nov. 

Type and only included species. Dilophodelphis fordycei, sp. nov.

Etymology. From the Greek words di (double), lophos (crest) and delphis (dolphin), referring to the enlarged supraorbital crests on the dorsal surface of the skull, resembling twin mountain crests. This construction also evokes the dinosaur Dilophosaurus wetherilli Welles 1954, a double-crested theropod recovered from Early Jurassic sequences of the Kayenta Formation in Arizona, USA.

Dilophodelphis fordycei, sp. nov. 

Figure 1. Skull of Dilophodelphis (USNM 214911) in dorsal view.
(a) Illustrated skull with low opacity mask, interpretive line art and labels for skull elements. Dotted lines indicate uncertainty of sutures, and dashed lines highlight fossae. Hatched pattern indicates areas where sediment is obscuring the fossil. (b) Photograph of skull in dorsal view, photography by James Di Loreto, Smithsonian Institution. fr., frontals; max., maxilla; n., nasal; pmx., premaxilla; pmx. sac fossa, premaxillary sac fossa. 

Figure 2. Skull of Dilophodelphis (USNM 214911) in ventral view.
(a) Illustrated skull with low opacity mask, interpretive line art and labels for skull elements. Dotted lines indicate uncertainty of sutures, and dashed lines highlight fossae. Hatched pattern indicates areas where sediment is obscuring the fossil. (b) Photograph of skull in ventral view, photography by James Di Loreto, Smithsonian Institution. fr., frontal; max., maxilla; p., pterygoid; v., vomer. 

The endangered South Asian river dolphin, Platanista gangetica (middle), swimming alongside two of its fossil relatives: the longirostral Pomatodelphis inaequalis (bottom) and the new species Dilophodelphis fordycei (top). None of the species lived together at the same time. Glow-throughs to the skulls highlight the diversity in supraorbital crest shape and size among the members of this family.
Image: Alex Boersma  @Boersma_Alex 


Figure 3. Skull of Dilophodelphis (USNM 214911) in right and left lateral views.
 (a) Illustrated skull in right lateral view and (b) left lateral view with low opacity mask, interpretive line art and labels for skull elements. Dotted lines indicate uncertainty of sutures, and dashed lines highlight fossae. Hatched pattern indicates areas where sediment is obscuring the fossil. (c) Photograph of skull in right lateral view and (d) left lateral view, photography by James Di Loreto, Smithsonian Institution. exocc., exoccipital; m., maxilla; par., parietal; p., pterygoid; sq., squamosal; temp. fossa, temporal fossa; zyg. process, zygomatic process. 


Etymology: The species epithet honours Prof. R. Ewan Fordyce, FRSNZ, native New Zealander and prominent vertebrate palaeontologist. The epithet recognizes his extensive and long-lasting contributions to the field of marine mammal palaeontology, including his commitment to mentoring future scientists, especially in shaping the career paths of the authors herein. The epithet also honours his long-standing interest in the fossil marine mammal record of Oregon, which has yielded pivotal specimens for over a century, including Simocetus rayi Fordyce 2002, which he described.



Alexandra T. Boersma, Matthew R. McCurry and Nicholas D. Pyenson. 2017. A New Fossil Dolphin Dilophodelphis fordycei Provides Insight Into the Evolution of Supraorbital Crests in Platanistoidea (Mammalia, Cetacea). Royal Society Open Science.  DOI: 10.1098/rsos.170022


New, ancient dolphin species had weird skull crests australiangeographic.com.au/news/2017/06/new,-ancient-dolphin-species-had-weird-skull-crests   @ausgeo - Australian Geographic 



---------------------------------------------------------------
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] Avicranium renestoi • A Bird-like Skull in A Triassic Diapsid Reptile Increases Heterogeneity of the Morphological and Phylogenetic Radiation of Diapsida ---ScRaBBlE


  Avicranium renestoi Pritchard & Nesbitt, 2017

Illustration: Matt Celeskey‏ @clepsydrops 

Abstract

The Triassic Period saw the first appearance of numerous amniote lineages (e.g. Lepidosauria, Archosauria, Mammalia) that defined Mesozoic ecosystems following the end Permian Mass Extinction, as well as the first major morphological diversification of crown-group reptiles. Unfortunately, much of our understanding of this event comes from the record of large-bodied reptiles (total body length > 1 m). Here we present a new species of drepanosaurid (small-bodied, chameleon-like diapsids) from the Upper Triassic Chinle Formation of New Mexico. Using reconstructions of micro-computed tomography data, we reveal the three-dimensional skull osteology of this clade for the first time. The skull presents many archaic anatomical traits unknown in Triassic crown-group reptiles (e.g. absence of bony support for the external ear), whereas other traits (e.g. toothless rostrum, anteriorly directed orbits, inflated endocranium) resemble derived avian theropods. A phylogenetic analysis of Permo-Triassic diapsids supports the hypothesis that drepanosaurs are an archaic lineage that originated in the Permian, far removed from crown-group Reptilia. The phylogenetic position of drepanosaurids indicates the presence of archaic Permian clades among Triassic small reptile assemblages and that morphological convergence produced a remarkably bird-like skull nearly 100 Myr before one is known to have emerged in Theropoda.

KEYWORDS: reptilia, phylogeny, convergence, Permo-Triassic extinction, evolutionary radiation, Triassic

Avicranium renestoi Pritchard & Nesbitt, 2017 
Illustration: Matt Celeskey‏ @clepsydrops 

Figure 2. Line drawing of the restored skull of Avicranium renestoi based on the three-dimensional surface renderings of skull elements in AMNH FARB 30834.

Figure 3. Reconstructed skull of Avicranium renestoi based on rearticulated three-dimensional surface rendering of the skull bones of AMNH FARB 30834.
Callouts include (a) reconstructed endocast in dorsal view, (b) skull roof in dorsal view, (c) postorbital complex (consisting of postfrontal and postorbital) in anterior view, (d) braincase and stapes in posterior view, (e) palatal complex in ventral view, (f) left quadrate in posterior view and (g) braincase and stapes in left lateral view. All bones have been rearticulated based on the facets of the reconstructed elements.

Abbreviations: fb, forebrain; mb, midbrain; pa, parietal; pf, postfrontal; pl, palatine; po, postorbital; pt, pterygoid; qu, quadrate; st, stapes; su, supratemporal. 


Systematic palaeontology

Diapsida
 Drepanosauromorpha 
 Drepanosauridae 
  Avicranium renestoi, n. gen., n. sp.

  Etymology: Avicranium, from aves (Latin for bird) and cranium (Latin for cranium), in reference to the suite of bird-like morphologies present in the holotype skull; renestoi, for Silvio Renesto, who described much of the drepanosauromorph fossil record from Triassic Italy.

  Holotype: AMNH FARB 30834, partial skull and articulated cervical series. Additional drepanosaurid caudal vertebrae and limb fragments are preserved in the block, but are not clearly associated with the individual to which the skull and cervical vertebrae belong.

  Locality: Coelophysis Quarry (‘siltstone member’, Chinle Formation). Recovered during preparation of the holotype block of the shuvosaurid pseudosuchian Effigia okeeffeae by S.J.N. [12].

 Diagnosis: Specimens for anatomical comparisons are listed in appendix C. A drepanosaurid diapsid differing from Hypuronector limnaios, Megalancosaurus preonensis and Vallesaurus cenensis (the only drepanosauromorphs with skull material) in the complete absence of teeth, a dorsoventrally taller retroarticular process with a triangular shape in lateral view, and cervical neural spines with subequal anteroposterior lengths and transverse widths.





Adam C. Pritchard and Sterling J. Nesbitt. 2017. A Bird-like Skull in A Triassic Diapsid Reptile Increases Heterogeneity of the Morphological and Phylogenetic Radiation of Diapsida. ROYAL SOCIETY OPEN SCIENCE.   DOI: 10.1098/rsos.170499 



---------------------------------------------------------------
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] Vadasaurus herzogi • A New Rhynchocephalian (Reptilia: Lepidosauria) from the Late Jurassic of Solnhofen (Germany) and the Origin of the Marine Pleurosauridae ---ScRaBBlE


Vadasaurus herzogi
 Bever & Norell, 2017


Abstract

A new rhynchocephalian is described based on a recently discovered and well-preserved specimen from the Late Jurassic (Kimmeridgian) marine limestones of Solnhofen, Bavaria. Phylogenetic analysis recovers the new taxon as the sister group to Pleurosauridae, a small radiation of rhynchocephalians representing the oldest marine invasion of crown-clade Lepidosauria. The relatively strong evidence for this taxonomically exclusive lineage, within a generally volatile rhynchocephalian tree, places the new taxon in a position to inform the early history of the pleurosaur transition to the sea. The early steps in this transition are distributed throughout the skeleton and appear to increase hydrodynamic efficiency for both swimming and aquatic feeding. This early history may also have included a global truncation of plesiomorphic ontogenetic trajectories that left a number of skeletal features with reduced levels of ossification/fusion. The exact degree to which Vadasaurus had adopted an aquatic ecology remains unclear, but the insight it provides into the origin of the enigmatic pleurosaurs exemplifies the potential of Rhynchocephalia for generating and informing broad-based questions regarding the interplay of development, morphology, ecology and macroevolutionary patterns.

KEYWORDSBavaria, marine reptile, secondarily aquatic, skeletal development, sphenodon, tiatethys



Figure 1. Holotype of Vadasaurus herzogi (AMNH FARB 32768) collected from the Late Jurassic marine limestones of Solnhofen, Bavaria. The skull, forelimbs, and first 18 presacral vertebrae and ribs are exposed in the dorsal or dorsolateral view. Posteriorly, the skeleton is rotated approximately 180°, making it visible largely in the ventral view. Left hindlimb is exposed in the dorsal view.
Anatomical abbreviations: As, astragalus; Ca, calcaneum; Cdv, caudal vertebra; Co, coracoid; Cr, cervical rib; Cv, cervical vertebra; D, dentary; Dv, dorsal vertebra; F, femur; Fb, fibula; Fr, frontal; Ga, gastralia; H, humerus; I, intermedium; Is, ischium; l, left; Mc, metacarpal; Mt, metatarsal; Mx, maxilla; Ph, phalanx; Pu, pubis; R, radius; r, right; S, scapula; Sc, sternal cartilage; Ss, suprascapular cartilage; Sv, sacral vertebra; T, tibia; U, ulna.

Figure 2. The skull of Vadasaurus herzogi (AMNH FARB 32768). Photographs in the dorsolateral (a) and lateral (b) views; labelled line drawing in the dorsolateral view (c); reconstructions of lateral and dorsal views (d).

Anatomical abbreviations: An, angular; Ar, articular; cp, cultriform process; Cv, cervical vertebra; D, dentary; dd, dentary dentition; Ecp, ectopterygoid; Ept, epipterygoid; exn, external naris; Fr, frontal; Hy, hyobranchial element; if, incisiform fang; Ju, jugal; mf, mandibular foramen; Mx, maxilla; Na, nasal; Pa, parietal; Pal, palatine; paf, parietal foramen; Pf, prefrontal; Pm, premaxilla; Po, postorbital; Pof, postfrontal; Pr, prootic; Pra, prearticular; Pt, pterygoid; Q, quadrate; Qj, quadratojugal; Sa, surangular; sof, suborbital fenestra; Sq, squamosal; Vo, vomer.


Systematic palaeontology

Lepidosauria Haekel, 1866 
Rhynchocephalia Günther, 1867 

Vadasaurus herzogi gen. et sp. no.

  Etymology: Generic name from the Latin vadare to go forth’, which is also the root of ‘to wade’—refers to the taxon's hypothesized phylogenetic position near the proximal end of a terrestrial-to-marine transformation series that produced the aquatic pleurosaurs—and saurus lizard’. The specific epithet honours the celebrated Bavarian film-maker Werner Herzog for his continuing exploration of the relationship between life and time.

Holotype: AMNH FARB 32768, a nearly complete and largely articulated skeleton (figures 1–3). Like most specimens preserved in lithographic limestone, it exhibits compressional effects that include the flattening and shearing of composite structures and the slight displacement of certain elements. Individual bones, however, are preserved largely in three dimensions.



Gabriel S. Bever and Mark A. Norell. 2017. A New Rhynchocephalian (Reptilia: Lepidosauria) from the Late Jurassic of Solnhofen (Germany) and the Origin of the Marine Pleurosauridae.  Royal Society Open Science. 4(11):170570  DOI:  10.1098/rsos.170570 


 The fossil was recovered from Kimmeridgian-aged (a subdivision of the Late Jurrasic) marine limestones in the Solnhofen municipality of Bavaria, Germany. They belong to an up until now unknown species dubbed Vadasaurus herzogi, and belongs to the Rhynchocephalia lizard order, a close relative of a small group of ancient reptiles called pleourosaurs (genus Pleurosaurus).
Fossilized ancient lizard shows how dinos evolved to live in the oceans 
zmescience.com/science/ancient-lizard-dino-evolve-ocean-0432/ @zmescience

---------------------------------------------------------------
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.

[Herpetology • 2017] Cyrtodactylus tanim • Morphological and Genetic Evidence for A New Karst Specialist Lizard from New Guinea (Cyrtodactylus: Gekkonidae) ---ScRaBBlE


Cyrtodactylus tanim 
 Nielsen & Oliver, 2017 


Abstract

Exposed limestone karst landscapes, especially in the tropics, are often home to distinctive and specialized biotas. Among vertebrates, a particularly large number of karst-associated lizard taxa have been described, but for the vast majority, evidence of specific adaptions to karst is lacking. A number of studies, however, have provided evidence of consistent morphological trends in lizards that use complex, three-dimensional, saxicoline habitats such as those that typify karst areas. Here we combine morphological and genetic data to test whether a newly discovered gecko from an extremely rugged karst area in New Guinea shows morphological trends matching those observed in other lizards associated with complex rock habitats such as karst and caves. Consistent with predictions, the new species' head is flatter and narrower than similar-sized relatives, and it has proportionally larger eyes and longer limbs. These trends indicate this taxon represents the second documented instance of karst specialization in a New Guinean vertebrate, and suggest morphological traits to test for evidence of specialized ecological associations in the many karst-associated Cyrtodactylus taxa from Southeast Asia.

KEYWORDS: Cyrtodactylus, ecological diversity, gecko, morphometric analysis, specialization

Figure 7. Cyrtodactylus tanim n. sp. in life. Paratypes SJR14637 (a,b) and NMV75961 (c) displaying juvenile coloration.

Photographs: Paul M. Oliver. 


Cyrtodactylus tanim n. sp.  

 Diagnosis: Cyrtodactylus tanim n. sp. can be distinguished from all other Melanesian and (Wallacean) Cyrtodactylus by the following unique combination of characters: moderate size (SVL to 96.7 mm) and slender, with a relatively narrow head (HW/SVL 0.17–0.19), mid-dorsal tubercles in 14–16 longitudinal rows at midpoint of body, ventrolateral fold without enlarged tubercles, subcaudal scales not transversely widened, pores in a tripartite series, precloacal pores obvious and of moderate number (15–17), femoral pores minute and numerous (31–30 per limb, 66–76 total), and dorsal colour pattern on torso consisting of six to nine semi-distinctly defined, alternating dark-brown bands or blotches, on a medium-brown background.

Distribution and natural history: Currently known from three sites spanning an elevation from approximately 540 to 1075 m.a.s.l. in near-impenetrable limestone country just east of Kaiangabip Village, Western Province, Papua New Guinea. Similar limestone country is widespread, but difficult to access, along the southern edge of the Central Cordillera, and this species is likely to have a wider range than is currently known.

A similar, moderately sized Cyrtodactylus with many dark-brown dorsal bands was seen—but not collected—in limestone areas in the north of Gulf Province. If this is also Cyrtodactylus tanim n. sp., then it will have a range spanning over 300 km.

Cyrtodactylus tanim n. sp. was collected in hill forest and lower montane forest where it was quite common, especially at higher elevations. Along a ridge of lower montane forest at approximately 1100 m.a.s.l. (figure 8), up to 10 specimens could reliably be seen over several hours of spotlighting on a single night. They were most commonly seen perched at relatively low heights (less than 3 m above substrate) on limestone faces, or on nearby small trees, roots, or lianas. Two eggs are visible in paratypes (NMV75958 and NMV75959) at varying stages of development.

Above 1000 m.a.s.l. Cyrtodactylus tanim n. sp. was the only gecko present, but at the two lower elevation sites (less than 900 m.a.s.l.) it occurred sympatrically with C. capreoloides and C. serratus. No habitat segregation with the former was obvious. Cyrtodactylus serratus appeared to be much rarer (six specimens in three weeks) and was observed at greater heights in the forest strata (e.g. on lianas or in larger forest trees more than 3 m above the ground), suggesting this much larger species is more arboreal than Cyrtodactylus tanim n. sp.

Figure 8. Habitat of Cyrtodactylus tanim n. sp.: lower montane forest on karst basement in Western Province, Papua New Guinea. Photograph: Paul M. Oliver. 

 Etymology: Tanim’, ‘Tanem’ or ‘Tanemkan’ is the ‘tokples’ name that Faiwol speakers from western Papua New Guinea gave specifically for Cyrtodactylus geckos, both on this survey, and earlier surveys undertaken by Fred Parker around Wangbin and Migalsimbip Villages in 1969 (personal communication). Incidentally, several local people including experienced hunters, showed distaste for Cyrtodactylus geckos, and were reluctant to touch, hold, or in the case of large specimens even look at them.


Stuart V. Nielsen and Paul M. Oliver. 2017. Morphological and Genetic Evidence for A New Karst Specialist Lizard from New Guinea (Cyrtodactylus: Gekkonidae).  Royal Society Open Science.  DOI: 10.1098/rsos.170781


---------------------------------------------------------------
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.

المشاركات الشائعة