[Paleontology • 2018] Caihong juji • A Bony-crested Jurassic Dinosaur with Evidence of Iridescent Plumage highlights Complexity in Early Paravian Evolution ---ScRaBBlE

Caihong juji 

Hu, Clarke, Eliason, Qiu, Li, Shawkey, Zhao, D’Alba, Jiang & Xu, 2018

  DOI:   10.1038/s41467-017-02515-y  
Illustration: Velizar Simeonovski

Abstract

The Jurassic Yanliao theropods have offered rare glimpses of the early paravian evolution and particularly of bird origins, but, with the exception of the bizarre scansoriopterygids, they have shown similar skeletal and integumentary morphologies. Here we report a distinctive new Yanliao theropod species bearing prominent lacrimal crests, bony ornaments previously known from more basal theropods. It shows longer arm and leg feathers than Anchiornis and tail feathers with asymmetrical vanes forming a tail surface area even larger than that in Archaeopteryx. Nanostructures, interpreted as melanosomes, are morphologically similar to organized, platelet-shaped organelles that produce bright iridescent colours in extant birds. The new species indicates the presence of bony ornaments, feather colour and flight-related features consistent with proposed rapid character evolution and significant diversity in signalling and locomotor strategies near bird origins.

Caihong juji  prepares to snatch its prey.

Illustration: Zhao Chuang

Fig. 1 Caihong juji holotype specimen (PMoL-B00175).
 Photographs of the slab (a) and counter slab (b) and line drawing (c) of the specimen based on both slabs. Photograph (d) and line drawing (e) of a composite of the rostrum of the skull and mandible exposed on the counter slab and the post-rostrum cranium exposed on the slab. Arrows indicate lacrimal crests. Question mark indicates uncertain identification. Scale bars: 10 cm a–c, 1 cm d and e.

 aof antorbital fenestra, cav caudal vertebra, cev cervical vertebra, dr dorsal rib, dv dorsal vertebra, ect ectopterygoid, emf external mandibular fenestra, en external naris, f feather, fu furcula, ga gastralia, hy hyoid, il ilium, is ischium, la left angular, lar left articular, lc left coracoid, lcr lacrimal crest, ld left dentary, lf left, frontal, lfe left femur, lh left humerus, lj left jugal, ll left lacrimal, lma left maxilla, lm left manus, ln left nasal, lp left pes, lpa left palatine, lpo left postorbital, lq left quadrate, lqj left quadratojugal, lr left radius, ls left scapula, lsp left splenial, lsa left surangular, lsq left squamosal, lt left tibiotarsus, lu left ulna, ma mandible, mf maxillary fenestra, o orbit, p parietal, pm premaxilla, pt pterygoid, pu pubis, rar right articular, rc right coracoid, rd right dentary, rfe right femur, rh right humerus, rm right manus, rp right pes, rpra right prearticular, rq right quadrate, rr right radius, rs right scapula, rt right tibiotarsus, ru right ulna, scl sclerotic bones, sk skull, sy synsacrum

Systematic palaeontology

Theropoda Marsh, 1881

Maniraptora Gauthier, 1986

Paraves Sereno, 1998

Caihong juji gen. et sp. nov.

 Etymology. Caihong is from the Mandarin ‘Caihong’ (rainbow), referring to the beautiful preservation of the holotype specimen of the animal and the array of insights it offers into paravian evolution; juji is from the Mandarin ‘ju’ (big) and ‘ji’ (crest), referring to the animal’s prominent lacrimal crests.

 Holotype. PMoL-B00175 (Paleontological Museum of Liaoning), a nearly complete skeleton with associated plumage preserved on a slab and counter slab from Gangou, Qinglong, northern Hebei Province, Tiaojishan Formation, early Late Jurassic, ~161 Myr.

 Diagnosis. A small theropod with the following autapomorphies within Paraves: accessory fenestra posteroventral to promaxillary fenestra, lacrimal with prominent dorsolaterally oriented crests, robust dentary with anterior tip dorsoventrally deeper than its midsection and short ilium (<50% of the femoral length, compared to considerably >50% in other theropods).

....

An artist's depiction of Caihong juji, a species of theropod dinosaur that lived 160 million years ago in what's now northeastern China.

Illustration: Velizar Simeonovski 

Dongyu Hu, Julia A. Clarke, Chad M. Eliason, Rui Qiu, Quanguo Li, Matthew D. Shawkey, Cuilin Zhao, Liliana D’Alba, Jinkai Jiang and Xing Xu. 2018. A Bony-crested Jurassic Dinosaur with Evidence of Iridescent Plumage highlights Complexity in Early Paravian Evolution. Nature Communications. 9, Article number: 217. DOI:   10.1038/s41467-017-02515-y

New 'Rainbow' Dinosaur May Have Sparkled Like a Hummingbird on.natgeo.com/2DyVWQR via @NatGeo
Little 'Rainbow' Dinosaur Discovered in China  shar.es/1NhEiQ via @LiveScience

  

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Ornithology • 2018] Structural Absorption by Barbule Microstructures of Super Black Bird of Paradise Feathers ---ScRaBBlE

Magnificent Riflebird Ptiloris magnificus during courtship display.

in  McCoy, Feo, Harvey & Prum, 2018.

photo: Tim Laman || DOI:  10.1038/s41467-017-02088-w 

Abstract
Many studies have shown how pigments and internal nanostructures generate color in nature. External surface structures can also influence appearance, such as by causing multiple scattering of light (structural absorption) to produce a velvety, super black appearance. Here we show that feathers from five species of birds of paradise (Aves: Paradisaeidae) structurally absorb incident light to produce extremely low-reflectance, super black plumages. Directional reflectance of these feathers (0.05–0.31%) approaches that of man-made ultra-absorbent materials. SEM, nano-CT, and ray-tracing simulations show that super black feathers have titled arrays of highly modified barbules, which cause more multiple scattering, resulting in more structural absorption, than normal black feathers. Super black feathers have an extreme directional reflectance bias and appear darkest when viewed from the distal direction. We hypothesize that structurally absorbing, super black plumage evolved through sensory bias to enhance the perceived brilliance of adjacent color patches during courtship display.

Magnificent Riflebird Bird of Paradise Ptiloris magnificus male displaying to female.

 photo: Tim Laman

Fig. 1  Six species of birds of paradise and one close relative.
a, b Species with normal black plumage patches. c–g Species with super black plumage patches.

a Paradise-crow Lycocorax pyrrhopterus. b Lesser Melampitta Melampitta lugubris, a Papuan corvoid closely related to birds of paradise.
c Princess Stephanie’s Astrapia Astrapia stephaniae. d Twelve-wired Birds-of-Paradise Seleucidis melanoleucus. e Paradise Riflebird Ptiloris paradiseus during courtship display. f Wahnes’ Parotia Parotia wahnesi. g Superb Bird-of-Paradise Lophorina superba during courtship display with female (brown plumage).

Photos: a @Hanom Bashari/Burung Indonesia; b Daniel López-Velasco; c Trans Niugini Tours; d–f Tim Laman; g Ed Scholes.  DOI:  10.1038/s41467-017-02088-w 

Fig. 3 Examples of normal and super black feather microstructure.
 a SEM micrograph of Lycocorax pyrrhopterus normal black feather with typical barbule morphology; scale bar, 200 µm. b SEM micrograph of Parotia wahnesi super black feather with modified barbule arrays; scale bar, 50 µm. c Gold sputter-coated normal black breast feather of Melampitta lugubris appears gold. d Gold sputter-coated super black breast feather of Ptiloris paradiseus retains a black appearance indicating structural absorption. SEM stubs are 12.8 mm in diameter.

DOI:  10.1038/s41467-017-02088-w 

A comparison of a normal feather, top left, and a feather from a paradise riflebird, top right.
The bottom panels are the feathers coated in gold. Notice how the riflebird’s still appears a deep black.

photos: Dakota McCoy 

Dakota E. McCoy, Teresa Feo, Todd Alan Harvey and Richard O. Prum. 2018. Structural Absorption by Barbule Microstructures of Super Black Bird of Paradise Feathers. Nature Communications. 9, Article number: 1. DOI:  10.1038/s41467-017-02088-w

Evolved illusion: Blackest black gives bird of paradise an edge  news.yale.edu/2018/01/09/evolved-illusion-blackest-black-gives-bird-paradise-edge

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Paleontology • 2017] Beibeilong sinensis • Perinate and Eggs of A Giant Caenagnathid Dinosaur from the Late Cretaceous of central China ---ScRaBBlE

 Beibeilong sinensis

Pu, Zelenitsky, Lü, Currie, Carpenter, Xu, Koppelhus, Jia, Xiao, Chuang, Li, Kundrát & Shen, 2017DOI: 10.1038/NComms14952

Abstract

The abundance of dinosaur eggs in Upper Cretaceous strata of Henan Province, China led to the collection and export of countless such fossils. One of these specimens, recently repatriated to China, is a partial clutch of large dinosaur eggs (Macroelongatoolithus) with a closely associated small theropod skeleton. Here we identify the specimen as an embryo and eggs of a new, large caenagnathid oviraptorosaur, Beibeilong sinensis. This specimen is the first known association between skeletal remains and eggs of caenagnathids. Caenagnathids and oviraptorids share similarities in their eggs and clutches, although the eggs of Beibeilong are significantly larger than those of oviraptorids and indicate an adult body size comparable to a gigantic caenagnathid. An abundance of Macroelongatoolithus eggs reported from Asia and North America contrasts with the dearth of giant caenagnathid skeletal remains. Regardless, the large caenagnathid-Macroelongatoolithus association revealed here suggests these dinosaurs were relatively common during the early Late Cretaceous.

Systematic palaeontology 

Theropoda Marsh 1881

Oviraptorosauria Barsbold 1976

Caenagnathidae Sternberg 1940

 Beibeilong sinensis gen. et sp. nov.

Figure 1: Photograph of eggs and skeleton of Beibeilong sinensis (HGM 41HIII1219).
Right image shows schematic overlay of approximate locations of individual eggs. Eggs 1 through 4 are in an upper layer just beneath the skeleton, whereas Egg 5 is in a lower layer of the block. Scale bar is in centimetre.

The fossil (left) and a digital overlay (right) shows where the eggs were placed before they broke and fossilized. Notice the skeleton of the embryo next to the ruler. 

Holotype. HGM 41HIII1219, a small, semi-articulated skeleton (‘Baby Louie’) associated with a partial nest of 6–8 eggs. The specimen is housed in the Henan Geological Museum (HGM), Zhengzhou, China.

the curled embryo of Beibelong on top of the eggs (eggshell is dark grey in color).

Photograph by Darla Zelenitsky, University of Calgary 

An illustration of Beibeilong embryo and egg fossil, with reconstruction of skeleton and fleshed-out models to the right. 

Figure 5: Reconstruction of Beibeilong embryo in ovo.
The drawing shows the approximate size of the Beibeilong embryo inside a Macroelongatoolithus egg.

drawn by Vladimir Rimbala

 Diagnosis. A large caenagnathid that has the following unique suite of features: antorbital fossa demarcated by sharply defined alveolar and dorsoposterior trending ridges, posterodorsal margin of lacrimal overlapped by frontal, subantorbital portion of the maxilla is inset medially, pronounced retroarticular process with a distinct concave posterior facet (roughly as tall at the base as it is wide), preacetabular process of the ilium longer than postacetabular process, posterior end of the postacetabular process truncated or broadly rounded, and accessory trochanter of the femur weakly developed.

 Locality and horizon. The specimen was discovered at a latitude/longitude of 33°15′30″ N, 111°43′41″ E in Heimaogou, 2 km east of Zhaoying Village, Yangcheng Township, Xixia County, Henan Province, People’s Republic of China. The locality is in the Upper Cretaceous Gaogou Formation (Cenomanian—Turonian)

Etymology. The generic name is derived from Chinese Pinyin ‘beibei’ for baby and ‘long’ for dragon. The specific name is derived from Latin referring to its discovery in China.

Beibeilong sinensis lived about 90 million years ago, during the Cretaceous period. The adults of this species were enormous, measuring up to 8 meters long from the snout to the end of the tail, and weighing up to 3,000 kilograms when fully grown at age 11.

Illustration: Zhao Chuang  

  

Hanyong Pu, Darla K. Zelenitsky, Junchang Lü, Philip J. Currie, Kenneth Carpenter, Li Xu, Eva B. Koppelhus, Songhai Jia, Le Xiao, Huali Chuang, Tianran Li, Martin Kundrát and Caizhi Shen. 2017. Perinate and Eggs of A Giant Caenagnathid Dinosaur from the Late Cretaceous of central China.  Nature Communications. 8, Article number: 14952. DOI: 10.1038/ncomms14952

First baby of a gigantic Oviraptor-like dinosaur belongs to a new species

 eurekalert.org/e/7Xft via @UCalgary @EurekAlert

'Baby Dragon' Dinosaur Found Inside Giant Egg  on.NatFeo.com/2pYHLPO via @NatGeo

Embryo of Colossal Dinosaur Was Preserved for 90 Million Years

shar.es/1FDLTy via @LiveScience

  

   

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Paleontology • 2017] Jianianhualong tengi • Mosaic Evolution in An Asymmetrically Feathered Troodontid Dinosaur with Transitional Features ---ScRaBBlE

Jianianhualong tengi  

Xu, Currie, Pittman, Xing, Meng, Lü, Hu & Yu, 2017 

 Life reconstruction by Julius T. Csotonyi | DOI: 10.1038/ncomms14972

Abstract
Asymmetrical feathers have been associated with flight capability but are also found in species that do not fly, and their appearance was a major event in feather evolution. Among non-avialan theropods, they are only known in microraptorine dromaeosaurids. Here we report a new troodontid, Jianianhualong tengi gen. et sp. nov., from the Lower Cretaceous Jehol Group of China, that has anatomical features that are transitional between long-armed basal troodontids and derived short-armed ones, shedding new light on troodontid character evolution. It indicates that troodontid feathering is similar to Archaeopteryx in having large arm and leg feathers as well as frond-like tail feathering, confirming that these feathering characteristics were widely present among basal paravians. Most significantly, the taxon has the earliest known asymmetrical troodontid feathers, suggesting that feather asymmetry was ancestral to Paraves. This taxon also displays a mosaic distribution of characters like Sinusonasus, another troodontid with transitional anatomical features.

Figure 1: Jianianhualong tengi holotype DLXH 1218.
 (a) Photograph and (b) line drawing of the specimen. Scale bar, 50 cm.

 cav, caudal vertebrae; cv, cervical vertebrae; dv, dorsal vertebrae; fu, furcula; lfe, left femur; lh, left humerus; li, left ilium; lis, left ischium; lm, left manus; lp left pes; lpu, left pubis; lr, left radius; lu, left ulna; md, mandible; rc, right coracoid; rfe, right femur; rfi, right fibula; rh, right humerus; ri, right ilium; rm, right manus; rr, right radius; rs, right scapula; rt, right tibiotarsus; ru, right ulna; sk, skull; ss, synsacrum. 

Figure 7: Life reconstruction of Jianianhualong tengi based on the holotype DLXH 1218.

by Julius T. Csotonyi 

Systematic palaeontology 

Theropoda Marsh, 188121
Coelurosauria Huene, 192022

Maniraptora Gauthier, 198623
Troodontidae Gilmore, 192424

Jianianhualong tengi gen. et sp. nov.

 Etymology. ‘Jianianhua’, the Chinese company that supported this study; ‘long’, the Chinese Pinyin for dragon. The specific name honors Ms Fangfang Teng, who secured the specimen for study.

 Holotype. DLXH 1218, a nearly complete skeleton with associated feathers (Fig. 1) housed at the Dalian Xinghai Museum.


Locality and horizon. Baicai Gou, Yixian County, western Liaoning, China; Lower Cretaceous Yixian Formation.

 Diagnosis. A troodontid distinguishable from other taxa in possessing the following apomorphic features (*indicates autapomorphic feature): maxillary rostral ramus triangular in outline and relatively high dorsoventrally*; maxillary ascending process extending posterodorsally at a high angle (an angle of ∼45° to maxillary ventral margin)*; lacrimal with a long descending process sub-equal in length to anterior process; a prominent ridge along anterior edge of the lateral surface of the lacrimal descending process; a distinct fossa on the dorsal surface of the surangular close to its posterior end; axial neural spine with a convex dorsal margin, transversely thickened anterior margin, and posterodorsal portion expanding strongly posteriorly; long manual phalanx II-1 (slightly shorter than metacarpal III) with prominent proximoventral heel, large groove along the medial surface of more than proximal half of manual phalanx II-1*; highly elongated manual III-2 (slightly longer than metacarpal III)*; robust ungual phalanges (medial ungual proximal depth/ungual length ratio >0.5); ilium with slightly concave dorsal margin in lateral view*; small medial lamina along ischial obturator process dorsal margin; metatarsal IV without prominent ventral flange*.

Figure 2: Cranium of Jianianhualong tengi holotype DLXH 1218.
 (a) Photograph and (b) line drawing of the skull and mandible. Scale bar, 2 cm.

ax, axis; fg, groove with foramina; fo, fossa; imf, internal mandibular fenestra; la, left angular; ld, left dentary; lect, left ectopterygoid; lex, left exoccipital; lf; left frontal; lhy, left hyoid bone; lj, left jugal; lla, left lacrimal; lm, left maxilla; lmf, left maxillary fenestra; ln, left nasal; lp, left parietal; lpt?, left pterygoid?; lpa, left prearticular; lpo, left postorbital; lpsaf, left posterior surangular foramen; lsa, left surangular; lsp?, left splenial?; lso, left supraoccipital; lsq, left squamosal; mc, Meckelian canal; ra, right angular; rart, right articular; rd, right dentary; rf, right frontal; rhy, right hyoid bone; rm?, right maxilla?; rn; right nasal; rp, right parietal; rpa, right prearticular; rq?, right quadrate?; rsa; right surangular; rso, right supraoccipital; rsp; right splenial; rsq, right squamosal. 

Xing Xu, Philip Currie, Michael Pittman, Lida Xing, Qingjin Meng, Junchang Lü, Dongyu Hu and Congyu Yu. 2017. Mosaic Evolution in An Asymmetrically Feathered Troodontid Dinosaur with Transitional Features.
  Nature Communications. 8, Article number: 14972.  DOI: 10.1038/ncomms14972

New Birdlike Dinosaur Had Modern Feathers on.natgeo.com/2p20KoN  @NatGeo

  

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[PaleoOrnithology • 2017] Cruralispennia multidonta • A Bizarre Early Cretaceous Enantiornithine Bird with Unique Crural Feathers and An Ornithuromorph Plough-shaped Pygostyle ---ScRaBBlE

Cruralispennia multidonta 

Wang, O’Connor, Pan & Zhou, 2017  

DOI: 10.1038/ncomms14141 

Abstract

Enantiornithes are the most successful clade of Mesozoic birds. Here, we describe a new enantiornithine bird, Cruralispennia multidonta gen. et sp. nov., from the Protopteryx-horizon of the Early Cretaceous Huajiying Formation of China. Despite being among the oldest known enantiornithines, Cruralispennia displays derived morphologies that are unexpected at such an early stage in the evolution of this clade. A plough-shaped pygostyle, like that of the Ornithuromorpha, evolved convergently in the Cruralispennia lineage, highlighting the homoplastic nature of early avian evolution. The extremely slender coracoid morphology was previously unknown among Early Cretaceous enantiornithines but is common in Late Cretaceous taxa, indicating that by 131 million years ago this clade had already experienced considerable morphological differentiation. Cruralispennia preserves unusual crural feathers that are proximally wire-like with filamentous distal tips, a new morphotype previously unknown among fossil or modern feathers, further increasing the known diversity of primitive feather morphologies.

Systematic palaeontology

Aves Linnaeus 1758

Ornithothoraces Chiappe 1995

Enantiornithes Walker 1981

Cruralispennia multidonta gen. et sp. nov.

 Etymology. The generic name is derived from Latin ‘Cruralis’ and ‘penna’, referring to the unique feathers on the tibiotarsus; the specific name is derived from Latin ‘mult’ and ‘donta’, referring to the numerous dentary teeth.

 Holotype. IVPP 21711 (housed at the Institute of Vertebrate Paleontology and Paleoanthropology), a nearly fully articulated partial skeleton with associated feathers preserved on a single slab.

Locality and horizon. The new specimen is collected from the Protopteryx-horizon of the Huajiying Formation at the Sichakou Basin, Fengning County, Hebei Province, northeastern China. Four other birds are reported from the same horizon, Eoconfuciusornis, Protopteryx, Eopengornis and Archaeornithura. Stratigraphic correlation and isotopic dating place this horizon at 130.7 Myr ago, late Early Cretaceous.

 Diagnosis. A small enantiornithine with the following unique features: 14 dentary teeth; abbreviated, plough-shaped pygostyle with a pygostyle/tarsometatarsus length ratio of about 0.28; coracoid mediolaterally narrow with the sternal margin measuring only one-quarter of the proximo-distal length; sternum bearing a V-shaped caudal margin and two pairs of subequal caudal trabeculae; manus shorter than the humerus; postacetabular process of the ilium short and strongly ventrally directed; dorsal process of the ischium more distally placed; and pubis without a distal expansion.

Figure 1: Cruralispennia multidonta holotype (IVPP V21711).
 (a) Photograph; (b) line drawing. ca, caudal vertebra; cv, cervical vertebra; il, ilium; is, ischium; lad, left alular digit; lco, left coracoid; lde, left dentary; lfe, left femur; lhu, left humerus; lmd, left major digit; lpd; left pedal digits; lra, left radius; lta, left tarsometatarsus; lti, left tibiotarsus; lul, left ulna; pu, pubis; py, pygostyle; qu, quadrate; rco, right coracoid; rfe, right femur; rhu, right humerus; rmd, right major digit; rpd, right pedal digits; rra, right radius; rsc, right scapula; rta, right tarsometatarsus; rti, right tibiotarsus; rul, right ulna; sk, skull; st, sternum; sy, synsacrum; tv, thoracic vertebra. The white circles (numbered 1–5) and box indicate the locations of the feather and histological samples, respectively. Scale bar, 10 mm. 

Figure 7: Major transitions of fibula and tail morphology across Mesozoic birds.
 The tree, simplified from the strict consensus tree produced by our phylogenetic analysis, is time-scaled using the ‘minimal branch length’ method with a minimum branch length of 1 Myr (see Supplementary Fig. 5 for complete result and node support values). The thick lines indicate the temporal range of fossil taxa. An elongated fibula (in red) is developed in non-ornithothoracine Aves, and the most basal enantiornithines Protopteryx and Pengornithidae; a reduced fibula is convergently evolved in the Ornithuromorpha and derived enantiornithines. Cruralispennia preserves a plough-shaped pygostyle (in pink), which has long been considered unique to Ornithuromorpha (the pink branches). The apparent absence of tail fanning in Cruralispennia indicates that the plough-shaped pygostyle and tail fanning is evolutionarily decoupled in this lineage (the silhouettes were from ref. 47; the reconstruction of tail feathers is on basis of refs 3, 30). 

Min Wang, Jingmai K O’Connor, Yanhong Pan and Zhonghe Zhou. 2017. A Bizarre Early Cretaceous Enantiornithine Bird with Unique Crural Feathers and An Ornithuromorph Plough-shaped Pygostyle. Nature Communications. 8, Article number: 14141. 

  DOI: 10.1038/ncomms14141

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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.