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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 Oligocene. Show all posts
Showing posts with label Oligocene. Show all posts

Wednesday, March 20, 2019

[PaleoMammalogy • 2017] Coronodon havensteini • The Origin of Filter Feeding in Whales ---ScRaBBlE


Coronodon havensteini  
Geisler, Boessenecker, Brown & Beatty, 2017


Illustration: A. Gennari DOI: 10.1016/j.cub.2017.06.003 

 Highlights
• A new species of 30 million year old whale has been found near Charleston, South Carolina
• This new species is a relative of modern baleen-bearing whales but retains teeth
• Its molars are large, multi-cusped, and overlapping and were used for filter feeding
• Filter feeding evolved before baleen; early whales had teeth and baleen

Summary
As the largest known vertebrates of all time, mysticetes depend on keratinous sieves called baleen to capture enough small prey to sustain their enormous size. The origins of baleen are controversial: one hypothesis suggests that teeth were lost during a suction-feeding stage of mysticete evolution and that baleen evolved thereafter, whereas another suggests that baleen evolved before teeth were lost. Here we report a new species of toothed mysticete, Coronodon havensteini, from the Oligocene of South Carolina that is transitional between raptorial archaeocete whales and modern mysticetes. Although the morphology and wear on its anterior teeth indicate that it captured large prey, its broad, imbricated, multi-cusped lower molars frame narrow slots that were likely used for filter feeding. Coronodon havensteini is a basal, if not the most basal, mysticete, and our analysis suggests that it is representative of an initial stage of mysticete evolution in which teeth were functional analogs to baleen. In later lineages, the diastema between teeth increased—in some cases, markedly so—and may mark a stage at which the balance of the oral fissure shifted from mostly teeth to mostly baleen. When placed in a phylogenetic context, our new taxon indicates that filter feeding was preceded by raptorial feeding and that suction feeding evolved separately within a clade removed from modern baleen whales.

Keywords: Mysticeti; filter feeding; baleen; oligocene; South Carolina; toothed mysticete


Systematics
Order Cetacea 
 Suborder Mysticeti 

Coronodon havensteini gen. et sp. nov.

Holotype: CCNHM 108. Nearly complete, 1.0-m-long skull, mandibles, 14 vertebrae, and partial ribs (Figures 1, 2, and 3; Figures S1–S3; Tables S1 and S2).

Etymology: Coronodon havensteini. Genus is Greek for “crown tooth,” referring to the multi-cusped molars. The species name recognizes Mark Havenstein, who discovered the holotype.

Locality and Age: Wando River near Highway 41 Bridge, South Carolina, Berkeley County. Ashley Formation, Oligocene, uppermost Rupelian. 

Diagnosis: Coronodon has the following mysticete synapomorphies: supraoccipital level with temporal fossa (character 25: state 1), broad basioccipital crests (39: 2), all cusps of posterior teeth subequal (99: 1), upturned antorbital process of maxilla (100: 1), and splayed basal cusps on posterior teeth (206: 1). Like some archaeocetes, its rostrum is twisted counterclockwise in anterior view (Figure 3). Coronodon havensteini is unique in having anterior lower molars labially overlapping posterior lower molars.  ....



Figure 1. Cranium and Upper Dentition of Coronodon havensteini sp. et gen. nov.
(A–E) Cranium in (A) lateral and (B) dorsal views. For comparison, (C) shows a dorsal view of the archaeocete Zygorhiza kochii (USNM 11962). Also shown of Coronodon are the left P3 in (D) labial and (E) lingual views. (F and G) Left M2 in (F) labial and (G) lingual views. (H and I) Right bulla in (H) dorsal view and left petrosal in (I) ventrolateral view. Portions in gray are reconstructed.
ap, anterior process of petrosal; cp, conical apophysis; fr, fenestra rotunda; Fr, frontal; lt, ventrolateral tuberosity; mf, fossa for malleus; Mx, maxilla; Na, nasal; ol, outer lip of bulla; os, occipital shield; Pa, parietal; pc, pars cochlearis; pbf, posterior facet for bulla; pgp, postglenoid process; pp, posterior process of bulla; Px, premaxilla; sp, sigmoid process; Sq, squamosal; sc, sagittal crest; Vo, vomer; zy, zygomatic process; VII canal for facial nerve. Scale bars in (A)–(C), 10 mm. Scale bars in (D)–(I), 5 mm. Blue denotes dental wear and red denotes dental erosion.

Coronodon havensteini  Geisler, Boessenecker, Brown & Beatty, 2017 



In this reconstruction, the two main whales in the center are Coronodon havensteini, the lower two in the background are Echovenator sandersi), and the birds in the sky are Pelagornis sandersi (false toothed birds with a wingspan near 6.5 m).
Illustration: Alberto Gennari  

Jonathan H. Geisler, Robert W. Boessenecker, Mace Brown and Brian L. Beatty. 2017. The Origin of Filter Feeding in Whales. Current Biology. In Press. DOI: 10.1016/j.cub.2017.06.003
Ancient South Carolina whale yields secrets to filter feeding's origins 
phy.so/417944795 via @physorg_com


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


كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا
شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

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

[PaleoMammalogy • 2017] New Records of the Dolphin Albertocetus meffordorum (Odontoceti: Xenorophidae) from the lower Oligocene of South Carolina: Encephalization, Sensory Anatomy, Postcranial Morphology, and Ontogeny of early Odontocetes ---ScRaBBlE


Albertocetus meffordorum   Uhen, 2008 

Boessenecker, Ahmed & Geisler, 2017

Abstract

We report five new specimens of xenorophid dolphins from North and South Carolina. Four of the specimens represent the xenorophid Albertocetus meffordorum, previously only known from the holotype skull. The other is a fragmentary petrosal from the upper Oligocene Belgrade Formation that we refer to Echovenator sp, indicating at least two xenorophids from that unit. Two of the Albertocetus meffordorum specimens are from the lower Oligocene Ashley Formation: 1) a partial skeleton with neurocranium, fragmentary mandible, ribs, vertebrae, and chevrons, and 2) an isolated braincase. The partial vertebral column indicates that Albertocetus retained the ancestral morphology and locomotory capabilities of basilosaurid archaeocetes, toothed mysticetes, and physeteroids, and caudal vertebrae that are as wide as tall suggest that the caudal peduncle, which occurs in all extant Cetacea, was either wide or lacking. CT data from the isolated braincase were used to generate a digital endocast of the cranial cavity. The estimated EQ of this specimen is relatively high for an Oligocene odontocete, and other aspects of the brain, such as its anteroposterior length and relative size of the temporal lobe, are intermediate in morphology between those of extant cetaceans and terrestrial artiodactyls. Ethmoturbinals are also preserved, and are similar in morphology and number to those described for the Miocene odontocete Squalodon. These fossils extend the temporal range of Albertocetus meffordorum into the early Oligocene, its geographic range into South Carolina, and expand our paleobiological understanding of the Xenorophidae.




Fig 1. Locality map of occurrences of Albertocetus meffordorum in North and South Carolina. (A) and a geologic map of Charleston, South Carolina (B), skeletal reconstruction of Albertocetus meffordorum with preserved elements in red (C), generalized stratigraphy at Belgrade Quarry (D)  and generalized Paleogene stratigraphy of the Charleston area (E). Gray in geologic map denotes Ashley Formation and black denotes Chandler Bridge Formation. 

Systematic paleontology

Cetacea Brisson, 1762
Pelagiceti Uhen, 2008

Odontoceti Flower, 1867
Xenorophidae Uhen, 2008

Albertocetus Uhen, 2008
Albertocetus meffordorum Uhen, 2008

.....

Conclusions

1. New odontocete specimens from the lower Oligocene Ashley Formation of South Carolina include an isolated cranium and a partial skeleton including incomplete cranium with petrotympanics and fragmentary mandible, cervical, thoracic, lumbar, and caudal vertebrae, ribs, and a chevron. These specimens extend the range of Albertocetus meffordorum into the early Oligocene.

2. Well-preserved petrosals permit more refined identification of a recently reported petrosal from the upper Oligocene Belgrade Formation of North Carolina as Echovenator sp., and permit referral of two additional Belgrade Formation petrosals to Albertocetus meffordorum and Echovenator sp. Future collecting efforts in North Carolina are expected to yield other cetaceans conspecific with those from the contemporaneous Chandler Bridge Formation of South Carolina.

3. The endocast of Albertocetus meffordorum is intermediate in morphology between extant odontocetes and archaeocete whales. Endocast volume indicates that Albertocetus meffordorum is the most highly encephalized odontocete from the early Oligocene (EQ = 2.586), well within the range of extant delphinoids, and chronicling a drastic jump in EQ across the Eocene-Oligocene boundary. Further study of appropriate body size estimation is needed to investigate the proposed Eocene-Oligocene explosion in odontocete encephalization.

4. The sample size of Albertocetus meffordorum permits the first basic examination of ontogenetic trends in stem Odontoceti. Ontogenetic study of Albertocetus meffordorum identifies several sutures of the dorsal braincase and facial region of interest for assessing ontogenetic status in stem Odontoceti (e.g. median parietal suture, frontoparietal suture, frontonasal suture, parieto-occipital suture), to be confirmed with larger samples of undescribed xenorophids (e.g. Echovenator, Xenorophus). Postcranial epiphyseal fusion is achieved earlier in ontogeny than cranial suture closure in A. meffordorum.

5. Vertebral proportions indicate that Albertocetus meffordorum, like basilosaurids, Mysticeti, and sperm whales, is a "pattern 1" species with no anteroposterior specialization of the vertebral column. This indicates that dorsoventral undulation occurred through the entire flexible lumbocaudal series; this appears to characterize stem odontocetes. Rectangular caudal vertebrae indicate the presence of caudal flukes. Surprisingly, no caudal vertebrae are transversely narrower than tall, suggesting the absence of a transversely narrowed peduncle as in all extant Mysticeti and Odontoceti. Such a feature would imply that the narrow peduncle evolved independently. However, skeletons of stem odontocetes and mysticetes with a more complete caudal series are required to further evaluate this hypothesis.


Robert W. Boessenecker,  Erum Ahmed and  Jonathan H. Geisler. 2017. New Records of the Dolphin Albertocetus meffordorum (Odontoceti: Xenorophidae) from the lower Oligocene of South Carolina: Encephalization, Sensory Anatomy, Postcranial Morphology, and Ontogeny of early Odontocetes. PLoS ONE. 12(11); e0186476.  DOI: 10.1371/journal.pone.0186476

New postcranial skeleton of ancient dolphin Albertocetus meffordum found in South Carolina  phy.so/429369468 via @physorg_com
 twitter.com/tetrameryx/status/929095659667492870
Fossils in @CofCNatHistory collections @CofC

  

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


كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا
شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

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

[PaleoMammalogy • 2017] Urkudelphis chawpipacha • A New Tropical Oligocene Dolphin from Montañita/Olón, Santa Elena, Ecuador ---ScRaBBlE


Urkudelphis chawpipacha
 Tanaka, Abella, Aguirre-Fernández, Gregori & Fordyce, 2017  


Abstract
A new small probable Oligocene dolphin from Ecuador represents a new genus and speciesUrkudelphis chawpipacha. The new taxon is known from a single juvenile skull and earbones; it differs from other archaic dolphins in features including widely exposed frontals at the vertex, a dorsally wide open vomer at the mesorostral groove, and a strongly projected and pointed lateral tuberosity of the periotic. Phylogenetic analysis places it toward the base of the largely-extinct clade Platanistoidea. The fossil is one of a few records of tropical fossil dolphins.


Systematic paleontology
CETACEA Brisson, 1762
NEOCETI Fordyce & de Muizon, 2001

ODONTOCETI Flower, 1867
PLATANISTOIDEA Gray, 1863 sensu Fordyce, 1994

Comment: Urkudelphis chawpipacha shows these synapomorphies of the Platanistoidea (sensu Fordyce, 1994), as recognised previously by Tanaka and Fordyce [2017]: periotic with C-shaped parabullary sulcus; small articular rim, which forms a ridge anterolateral to posterior process of periotic and separated from it by a sulcus. Two phylogenies place Urkudelphis near the base of the Platanistoidea (sensu lato; including Platanistidae, Squalodelphis, Notocetus, Phocageneus, Otekaikea, Waipatiidae, Awamokoa and Squalodontidae [2017]).

Fig 2. Skull, Urkudelphis chawpipacha MO-1 (holotype) in dorsal view. Left, photo, right, line art.

Fig 4. Skull, Urkudelphis chawpipacha MO-1 (holotype) in right lateral view. Upper, photo, lower, line art.

Urkudelphis gen. nov.

Type species: Urkudelphis chawpipacha sp. nov.

Urkudelphis chawpipacha sp. nov.

Diagnosis: Urkudelphis chawpipacha is a small archaic odontocete with the following autapomorphic combination of characters: shallow antorbital notch (character 10); anteromedially oriented anterior edge of the supraorbital process (character 37); weakly dorsally convex nuchal crest in dorsoposterior view (character 119); approximately same sized apertures of the vestibular aqueduct and cochlear aqueduct (character 186); dorsoventrally thin pars cochlearis on the periotic (character 192); inner posterior prominence of the tympanic bulla is anterior to the outer posterior prominence (character 218); very strongly projecting and pointed lateral tuberosity; and an anteroposteriorly long accessory ossicle of the periotic. Urkudelphis chawpipacha differs from early branching odontocetes, including Agorophius, Ashleycetus, Simocetus, Mirocetus and Xenorophus in having the frontals on the vertex at a level behind the postorbital process; anteroposteriorly shorter and transversely wider frontals (approaching a square-shape rather than narrow and elongate); and parallel-sided posterior part of the ascending process of each maxilla forming a narrow elongate face. Urkudelphis differs from Early Miocene Papahu taitapu, Chilcacetus cavirhinus, Arktocara yakataga, Allodelphis pratti and Ninjadelphis ujiharai, having the frontals on the vertex flat and longer than the taxa above, which have more nodular and shorter frontals. Urkudelphis differs from Chilcacetus and Papahu in having a narrow premaxillary sac fossa. Urkudelphis chawpipacha also notably shows: frontals at the vertex invaded posteriorly by the interparietal; and long anteromedial projection of the palatine on the palate. Other diagnostic features of U. chawpipacha are shared with more-crownward Waipatiidae: a shallow suprameatal pit of the squamosal (character 152); an abruptly ventrally deflected anterior process of the periotic (character 172); and a nearly flat dorsal surface of the periotic in lateral view (character 181). In addition, Urkudelphis chawpipacha shares several characters with more-crownward Platanistoidea: a periotic with C-shaped parabullary sulcus (character 175); and a small articular rim, which forms a ridge anterolateral to the posterior process of the periotic and separated from it by a sulcus (character 195).

Holotype: MO-1, an incomplete skull (premaxilla, maxilla, vomer, pterygoid, frontal, parietal, interparietal, alisphenoid, squamosal and supraoccipital), including the right periotic, right tympanic bulla and right malleus.

Etymology: The generic name, Urkudelphis originates from Kichwa “urku” meaning mountain, referring to the type locality of Montañita, and Greek “delphis” for dolphin, which has been used widely as a suffix for dolphin generic names. Chawpipacha results from the combination of chawpi, meaning "half" or “middle” and pacha, meaning "the world" representing the equator, and thus Ecuador in Kichwa.

Type locality: MO-1 was found by one of the authors (JA) and several UPSE students in August 2015 in a boulder that collapsed from a cliff at the coastal locality here named Montañita/Olón (latitude 1°48'50.64" S, longitude 80°45'24.18" W). The Montañita/Olón (MO) locality (Fig 1) lies midway between the towns of Montañita and Olón (Santa Elena Province, Ecuador) and can only be accessed during low tides.
Conclusion: 
A new small dolphin from probable Oligocene (Chattian?) strata in Santa Elena, Ecuador is described as a new species and genus, Urkudelphis chawpipacha. The new taxon is characterized by: an anteromedially oriented anterior edge of the supraorbital process; weakly convex nuchal crest in dorsoposterior view; approximately same sized apertures of vestibular aqueduct and cochlear aqueduct; dorsoventrally thin pars cochlearis on periotic; and inner posterior prominence placed anterior to the outer posterior prominence. Urkudelphis chawpipacha differs from other Oligocene dolphins in the combination of: frontals on the vertex at a level posterior to the postorbital process; shorter and wider frontals; and parallel-sided posterior part of the ascending process of the maxilla. Phylogenetic analysis places it near the base of the largely-extinct clade Platanistoidea. The fossil is one of few fossil Neoceti reported from the equator, and is a reminder that Oligocene cetaceans may have ranged widely in tropical waters.


Yoshihiro Tanaka, Juan Abella, Gabriel Aguirre-Fernández, Maria Gregori and R. Ewan Fordyce. 2017. A New Tropical Oligocene Dolphin from Montañita/Olón, Santa Elena, Ecuador. PLoS ONE. 12(12); e0188380.  DOI: 10.1371/journal.pone.0188380

New ancient dolphin species Urkudelphis chawpipacha discovered in Ecuador http://phy.so/432980137 via @physorg_com


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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.

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


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


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


Systematic Palaeontology  

Teleostei Müller, 1845
Anabantiformes sensu Wiley and Johnson, 2010

Anabantoidei sensu Lauder and Liem, 1983
Anabantidae Bonaparte, 1839

Eoanabas thibetana gen. et sp. nov.

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

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

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

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

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


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

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


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

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



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

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



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


كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا
شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

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

[PaleoMammalogy • 2017] Wakaleo schouteni • A New Oligo–Miocene Marsupial Lion from Australia and Revision of the Family Thylacoleonidae ---ScRaBBlE


Wakaleo schouteni Gillespie, Archer & Hand, 2017
challenging the thylacinid Nimbacinus dicksoni over a kangaroo carcass in the late Oligocene forest at Riversleigh  

illustration by Peter Schouten  DOI: 10.1080/14772019.2017.1391885 

Abstract

Wakaleo schouteni sp. nov., a dog-sized marsupial lion (Thylacoleonidae), is described from late Oligocene to early Miocene sediments of the Riversleigh World Heritage Area, Queensland, Australia. Fossils of this new species include a near-complete cranium, dentaries and postcrania. This species is the second thylacoleonid known from late Oligocene sediments. The other, Priscileo pitikantensis Rauscher, 1987, from the Etadunna Formation of South Australia, is known from teeth, part of a palate and postcrania. Wakaleo schouteni exhibits cranial and dental morphology characteristic of species of Wakaleo but possesses a relatively plesiomorphic upper dental formula (i.e. three premolars and four molars) within Thylacoleonidae that was formerly regarded to be diagnostic for species of the genus Priscileo. The holotype and humerus of P. pitikantensis have been compared with the new Wakaleo material described here and found to demonstrate conspicuous similarities in morphology of the M2 and the humerus. In the absence of other generically diagnostic features, Priscileo is here regarded to be a junior synonym of Wakaleo. Smaller size and relatively minor morphological differences in the proximal humerus of W. pitikantensis comb. nov. distinguish it at the specific level from W. schouteni. Phylogenetic analysis of thylacoleonids recovers Wakaleo as a monophyletic clade. Both Wakaleo pitikantensis comb. nov. and W. schouteni are recovered as plesiomorphic sister taxa to other species of the genus. Wakaleo pitikantensis and W. schouteni extend the temporal range for this genus back into the late Oligocene. Body weight for W. schouteni, based on total skull length, is estimated to be ∼23 kg.

Keywords: marsupial lion, Thylacoleonidae, Oligocene–Miocene, taxonomy, Priscileo, Riversleigh


Systematic palaeontology

Class Marsupialia Illiger, 1811 

Order Diprotodontia Owen, 1866 
Suborder Vombatiformes Woodburne, 1984 

Family Thylacoleonidae Gill, 1872 

Genus Wakaleo Clemens & Plane, 1974 

Type species: Wakaleo oldfieldi Clemens & Plane, 1974 
.
Included species: Wakaleo vanderleueri Clemens & Plane, 1974; Wakaleo alcootaensis Archer & Rich, 1982; Wakaleo schouteni sp. nov.

  Reconstruction of Wakaleo schouteni challenging the thylacinid Nimbacinus dicksoni over a kangaroo carcass in the late Oligocene forest at Riversleigh.
(illustration by Peter Schouten).

Wakaleo schouteni sp. nov.

Derivation of name: Named in honour of Peter Schouten for his exceptional reconstructions of Australia's prehistoric animals, and in particular those from the Riversleigh WHA.


Conclusions
Craniodental and postcranial material of a new marsupial lion, Wakaleo schouteni sp. nov., is described from the Riversleigh WHA. Although this taxon has not reduced/lost the anterior upper premolars, previously regarded to be diagnostic for Wakaleo, it exhibits other Wakaleo apomorphies of the skull and molars. Comparison of the holotype of Priscileo pitikantensis Rauscher, 1987 from the Ngapakaldi LF with Wakaleo schouteni sp. nov. and other Wakaleo species reveals apomorphies of the M2 and similarities in humerus morphology that support its referral to Wakaleo. Priscileo pitikantensis is therefore regarded as a junior synonym of Wakaleo pitikantensis comb. nov. Wakaleo schouteni is distinguished from W. pitikantensis on the basis of its different proximal humerus morphology and larger size, being 10% larger in most dental measures. Markedly different sizes in a sample of humeri of W. schouteni suggest this species was sexually dimorphic. Retention of three upper premolars and four molars are symplesiomorphic features for Wakaleo and Priscileo but distinguish W. pitikantensis and W. schouteni from later species of this genus, all of which exhibit premolar and molar reduction. These two species are the most primitive members of the genus and indicate a pre-late Oligocene origin for the lineage.


Anna K. Gillespie, Michael Archer and Suzanne J. Hand. 2017. A New Oligo–Miocene Marsupial Lion from Australia and Revision of the Family Thylacoleonidae. Journal of Systematic Palaeontology. DOI: 10.1080/14772019.2017.1391885

  

Fossils of ancient marsupial lion discovered in north-west Queensland
AustralianGeographic.com.au/news/2017/12/fossils-of-ancient-marsupial-lion-discovered-in-north-west-queensland via @
AusGeo

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


كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا
شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

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

[PaleoMammalogy • 2017] Inermorostrum xenops • A Toothless Dwarf Dolphin (Odontoceti: Xenorophidae) Points to Explosive Feeding Diversification of Modern Whales (Neoceti) ---ScRaBBlE


Inermorostrum xenops
Boessenecker, Fraser, Churchill & Geisler, 2017


Abstract

Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones—all adaptations for suction feeding upon fishes and squid. We report a new fossil odontocete from the Oligocene (approx. 30 Ma) of South Carolina (Inermorostrum xenops, gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour among modern Odontoceti.

KEYWORDS: Xenorophidae, Odontoceti, Neoceti, suction feeding, Oligocene




Etymology. The generic name is from the Latin inermus, meaning weapon-less or defenceless, and rostrum, meaning snout, referring to the absence of teeth in the rostrum. The species name derives from Greek for strangexeno, and faceops, referring to the highly derived facial morphology of the holotype.


Robert W. Boessenecker, Danielle Fraser, Morgan Churchill and Jonathan H. Geisler. 2017. A Toothless Dwarf Dolphin (Odontoceti: Xenorophidae) Points to Explosive Feeding Diversification of Modern Whales (Neoceti). Proceedings of the Royal Society B. DOI: 10.1098/rspb.2017.0531

This ancient dwarf dolphin may have slurped its food like a walrus  sciencemag.org/news/2017/08/ancient-dwarf-dolphin-may-have-slurped-its-food-walrus

   

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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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