[PaleoMammalogy • 2017] Mystacodon selenensis • Earliest Mysticete from the Late Eocene of Peru Sheds New Light on the Origin of Baleen Whales ---ScRaBBlE

Mystacodon selenensis 

Lambert, Martínez-Cáceres, Bianucci, Celma, Salas-Gismondi, Steurbaut, Urbina & Muizon, 2017

 DOI:  10.1016/j.cub.2017.04.026 

Highlights

• An ancient whale is described based on a skeleton from the late Eocene of Peru

• It is identified as the earliest known mysticete (baleen whales and relatives)

• Skeletal anatomy provides crucial information on archaeocete-mysticete transition

• This whale is interpreted as specialized for suction and possibly benthic feeding

Summary

Although combined molecular and morphological analyses point to a late middle Eocene (38–39 million years ago) origin for the clade Neoceti (Odontoceti, echolocating toothed whales plus Mysticeti, baleen whales, and relatives), the oldest known mysticete fossil dates from the latest Eocene (about 34 million years ago) of Antarctica. Considering that the latter is not the most stemward mysticete in recent phylogenies and that Oligocene toothed mysticetes display a broad morphological disparity most likely corresponding to contrasted ecological niches, the origin of mysticetes from a basilosaurid ancestor and its drivers are currently poorly understood. Based on an articulated cetacean skeleton from the early late Eocene (Priabonian, around 36.4 million years ago) of the Pisco Basin, Peru, we describe a new archaic tooth-bearing mysticete, Mystacodon selenensis gen. et sp. nov. Being the geologically oldest neocete (crown group cetacean) and the earliest mysticete to branch off described so far, the new taxon is interpreted as morphologically intermediate between basilosaurids and later toothed mysticetes, providing thus crucial information about the anatomy of the skull, forelimb, and innominate at these critical initial stages of mysticete evolution. Major changes in the morphology of the oral apparatus (including tooth wear) and flipper compared to basilosaurids suggest that suction and possibly benthic feeding represented key, early ecological traits accompanying the emergence of modern filter-feeding baleen whales’ ancestors.

Systematics

Cetacea

Pelagiceti

Neoceti

Mysticeti

Mystacodontidae fam. nov.

Mystacodon selenensis gen. et sp. nov.

Etymology: From ancient Greek mystacos (“moustache”) in reference to the suborder Mysticeti and odontos (“tooth”), “mysticete with teeth,” and from Selene, the Greek goddess of the moon, in reference to the Playa Media Luna type locality.

Figure 1: Cranium, Mandible, and Teeth of Mystacodon selenensis gen. et sp. nov. MUSM 1917.

Cranium in dorsal (A), left lateral (B), and ventral (C) views; detail of left posterior lower teeth in lateral view (D); left mandible in lateral (E) and dorsal (F) views; and three detached anterior lower teeth (from left to right: incisor, incisor/canine, and ?p1) in lingual or labial and occlusal views (G).

aof, antorbital foramina; apm, antorbital process of maxilla; bn, bony nares; C, upper canine; c, lower canine; cp, coronoid process; ep, embrasure pit; I1–I3, upper incisors; i1–i3, lower incisors; iop, infraorbital plate; ju, jugal; la, lacrimal; M1 and M2, upper molars; m1–m3, lower molars; maf, mandibular fossa; mf, mental foramina; mg, mesorostral groove; mx, maxilla; na, nasal; nc, nuchal crest; P1–P4, upper premolars; p1–p4, lower premolars; pa, parietal; pmx, premaxilla; prpf, preorbital process of frontal; pspf, postorbital process of frontal; sq, squamosal; sym, mandibular symphysis; zpm, zygomatic process of maxilla; zyg, zygomatic process of squamosal. Scale bars for (A)–(C), (E), and (F), 200 mm; for (D), 20 mm; and for (G), 10 mm.   

Two Mystacodon selenensis individuals diving down to catch eagle rays along the seafloor of a shallow cove off the coast of present-day Peru.

Illustration: Alberto Gennari 

Holotype: Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (MUSM; Lima, Peru) 1917, partial skeleton including cranium, mandibles, teeth, cervical, thoracic, lumbar and caudal vertebrae, ribs, partial right and left forelimbs, and left innominate.

Locality: Playa Media Luna, southern part of Pisco Basin, southern coast of Peru, ...

Horizon: Middle part of the Yumaque Formation, 77 m above the base; lower part of calcareous nannofossil zone NP19/20 of Martini; dated at 36.4 million years ago based on age estimations used by Agnini et al. [2014]; early late Eocene (early Priabonian; see Figures S1A and S1D, Table S1, and STAR Methods for the biostratigraphic and biochronological interpretations).

Diagnosis: MUSM 1917 is identified as a Neoceti based on the following derived characters, absent in basilosaurid archaeocetes: partly open mesorostral groove; anteroposteriorly elongated rostral portion of maxilla; loss of sagittal crest; supraoccipital shield anterodorsally inclined; apex of zygomatic process of squamosal nearly contacting postorbital process of frontal; and distal epiphysis of the humerus divided in two angled radial and ulnar facets. It can be referred to the Mysticeti due to the following combination of derived characters: dorsoventrally thin lateral edge of maxilla on rostrum; presence of an antorbital process of the maxilla; presence of a maxillary infraorbital plate; and triangular supraoccipital shield. It is further diagnosed by two possibly autapomorphic features: nasal anteroposteriorly longer than frontal plus parietal and strong tuberosity on anterior edge of radius; two additional derived characters: posteriormost upper tooth anterior to level of antorbital process of maxilla and broad-based rostrum (ratio between width of skull at rostrum base and width at postorbital process > 0.8); and a series of plesiomophic features: supraoccipital shield not extending anterior to anterior level of squamosal fossa, only two dorsal infraorbital foramina, a basilosaurid dental formula 3.1.4.2/3.1.4.3, no wide diastemata between posterior cheek teeth, sutured mandibular symphysis, and well-defined acetabulum on innominate. Finally, MUSM 1917 lacks cranial synapomorphies of Odontoceti: facial concavity, presence of premaxillary foramen and premaxillary sac fossa, and posterior expansion of maxilla over the supraorbital region (Figures 1, 2, 3, and S2).

Members of the excavation team digging around the skeleton of Mystacodon selenensis at the Media Luna locality in the Pisco Basin, Peru.

photo: Giovanni Bianucci  

Olivier Lambert, Manuel Martínez-Cáceres, Giovanni Bianucci, Claudio Di Celma, Rodolfo Salas-Gismondi, Etienne Steurbaut, Mario Urbina and Christian de Muizon. 2017. Earliest Mysticete from the Late Eocene of Peru Sheds New Light on the Origin of Baleen Whales. Current Biology.  In Press.  DOI:  10.1016/j.cub.2017.04.026

    

36m-year-old fossil discovery is missing link in whale evolution, say researchers TheGuardian.com/science/2017/may/11/36m-year-old-fossil-discovery-is-missing-link-in-whale-evolution-say-researchers-mystacodon-selenensis

Baleen whales' ancestors were toothy suction feeders http://phy.so/413697728 via @physorg_com

This ancient whale likely sucked prey into its mouth like a giant vacuum cleaner https://www.theverge.com/tldr/2017/5/11/15610764/mysticete-whale-ancestor-suction-feeder-evolution  via @Verge

---------------------------------------------------------------

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.

[PaleoMammalogy • 2017] Anatoliadelphys maasae • Skeleton of An Unusual, Cat-sized Marsupial Relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian) of Turkey ---ScRaBBlE

Anatoliadelphys maasae  Maga & Beck, 2017

 DOI: 10.1371/journal.pone.0181712 

Abstract

We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere metatherians during the first half of the Cenozoic.

Systematic palaeontology

Mammalia; Theria

Metatheria; Marsupialiformes

Anatoliadelphys gen. nov.  

Anatoliadelphys maasae sp. nov.  

Etymology: Anatolia (Greek): the geographic name for the Asian part of Turkey; delphys (Greek): uterus, a common suffix for marsupials and their fossil relatives; maasae: in honour of Dr. Mary Maas and her contributions to Paleogene mammalian palaeontology, particularly in Turkey.

Holotype: Ankara Üniversitesi Jeoloji Müzesi (AÜJM) specimen 2002–25, which comprises a fragmented partial cranium, both dentaries, and associated postcranial elements, including most of the vertebral column, partial pectoral and pelvic girdles, all of the long limb bones, both calcanei, two metapodials, and a few phalanges.

Locality and age: AÜJM 2002–25 was collected from the Lülük member of the Uzunçarşıdere Formation (UCF), which is part of the small Orhaniye-Güvenç sedimentary basin located at the northwestern edge of the city of Ankara, approximately 5 km southwest of the town of Kazan, in central Turkey. The Lülük member is the lowest of the three members currently recognised within the UCF (together with the Gökdere [middle], and Sarıbeyler [upper] members), and is the source of all fossil mammals known from the UCF to date. AÜJM 2002–25 is from locality AK33, which is approximately 90m above the base of the UCF, at Memlik village. Until recently, the age of the UCF was poorly constrained, but a combination of U-Pb dating of zircons and magnetostratigraphy now support a date of 44–42 MYA (= Lutetian) for the formation as a whole, and 44–43 MYA for the Lülük member.

Diagnosis: Anatoliadelphys maasae differs from all other metatherians in the following combination of features: comparatively large size (estimated body mass 3–4 kg); premolars increase markedly in size posteriorly (occlusal area of p1 less than one sixth that of p3); P3 and p3 very large (similar in occlusal area to M2 and m2 respectively) and also broad (labiolingual width:mesiodistal length ratio is 0.89 for P3 and 0.7 for p3); modified tribosphenic molar dentition, in which M1-3 and m1-4 increase markedly in size posteriorly (occlusal area of M1 approximately one third that of M3; occlusal area of m1 approximately one seventh that of m4); upper molars with cingula extending along the anterior and posterior margins; protocone large but conules indistinct or absent; metacone taller than the paracone on M3 but smaller than the paracone on M4; centrocrista v-shaped on M3, with the premetacrista extending labially to stylar cusp D; centrocrista straight on M4; parastylar lobe very large on M4; anterior cingulid weakly developed on m3-4; m4 trigonid dominated by enormous protoconid, with paraconid and metaconid both greatly reduced; preentocristid and cristid obliqua of m3-4 both with carnassial notch; posterior cingulid present but very faint on m3-4; strongly curved radius and tibia; femur with prominent third trochanter, well-marked trochlea and distal condyles of approximately equal width; calcaneus with medially-inflected tuber, large peroneal process with prominent groove for peroneus longus tendon, concave calcaneocuboid facet, and prominent pit (probably for plantar calcaneocuboid ligament) on ventral surface.

.....

Fig 1. Holotype skeleton of Anatoliadelphys maasae (AÜJM 2002–25). Scale bar = 5 cm. 

Reconstruction of the Anatoliadelphys maasae.

Illustration: Peter Schouten 

A. Murat Maga and Robin M. D. Beck. 2017. Skeleton of An Unusual, Cat-sized Marsupial Relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey.  PLoS ONE. 12(8); e0181712.  DOI: 10.1371/journal.pone.0181712

Cenozoic carnivore from Turkey may have evolved without placental competitors  phy.so/422094230 via @physorg_com

Ancient Carnivorous Dread-Possum Is Upending The History Of Mammals | Gizmodo Australia (via @GizmodoAU)  www.gizmodo.com.au/2017/08/ancient-carnivorous-dread-possum-is-upending-the-history-of-mammals/

---------------------------------------------------------------

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] Exceptional Soft Tissues Preservation in A Mummified Frog-eating Eocene Salamander, Phosphotriton sigei ---ScRaBBlE

Fossil specimen of Phosphotriton sigei, an exceptionally preserved 40-35 million years old salamander (left part) and its internal organs conserved within it (right part). The skeleton, in grey, is perfectly preserved, as well as several soft organs such as the gut and lung. Within the stomach, the last meal of the animal is also preserved. Surprisingly, it fed on a frog, an extremely rare kind of prey for salamanders. Accessing the internal anatomy of this fossil without destroying it could only be achieved through modern synchrotron technology.

DOI:  10.7717/peerj.3861

Abstract

Fossils are almost always represented by hard tissues but we present here the exceptional case of a three-dimensionally preserved specimen that was ‘mummified’ (likely between 40 and 34 million years ago) in a terrestrial karstic environment. This fossil is the incomplete body of a salamander, Phosphotriton sigei, whose skeleton and external morphology are well preserved, as revealed by phase-contrast synchrotron X-ray microtomography. In addition, internal structures composed of soft tissues preserved in three dimensions are now identified: a lung, the spinal cord, a lumbosacral plexus, the digestive tract, muscles and urogenital organs that may be cloacal glands. These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander. Indeed, the digestive tract contains remains of a frog, which represents the only known case of an extinct salamander that fed on a frog, an extremely rare type of predation in extant salamanders. These new data improve our scarce knowledge on soft tissue anatomy of early urodeles and should prove useful for future biologists and palaeontologists working on urodele evolutionary biology. We also suggest that the presence of bat guano and carcasses represented a close source of phosphorus, favouring preservation of soft tissues. Bone microanatomy indicates that P. sigei was likely amphibious or terrestrial, and was probably not neotenic.

 Synchrotron tomography permitted access to the inside of the skeleton of Phosphotriton sigei. The skeleton and several organs are perfectly preserved.

photo: Jérémy Tissier  

Figure 1: Specimen MNHN.F.QU17755, holotype of Phosphotriton sigei. (A and B) Fossil in dorsal and ventral views. Some characteristics of urodeles, such as costal grooves or scaleless skin, are observable on the external aspect of the specimen. The cloaca and vertebral column are visible. The dotted line represents the position of the tomogram illustrated in Fig. 1C. (C) Tomogram of the tail part of the animal showing the muscles, in green, ventral and lateral to the vertebrae, and the spinal cord preserved inside the neural canal of a vertebra. Bony material is characterized by a dark grey shade, because of its light density, compared to the mineral matrix (grey or white) and void (black). Soft-tissues are also mostly darker than the mineral matrix, but are mainly recognizable by their structure and shape, on tomograms or in 3D. (D) 3D reconstruction of undetermined tail muscles, in green, which could attach to the ischium or femur. Dotted line represents the position of the tomogram illustrated in Fig. 1C.

Discussion

Ecology. The presence of anuran bones in the digestive tract of the fossil (Figs. 3C–3E) is evidence of a type of predation that is very rare in urodeles. Preying on frogs was reported in Amphiuma (Montaña, Ceneviva-Bastos & Schalk, 2014), a large and especially voracious extant urodele. Another voracious urodele, Necturus, has been reported (Hamilton, 1932) to have eaten other urodeles (Desmognatus and Eurycea), but not frogs. P. sigei was relatively small and the swallowed anuran, although small, was likely a metamorphosed individual, as shown by the well-shaped humeral condyle, but not a fully grown adult, as shown by the broad neural canal, assuming that the vertebrae belong to the same individual as the humerus. The straight diaphysis of the humerus and the position of the humeral condyle in line with the diaphysis suggest that the prey was a ranoid. Ranoids were already reported from the Phosphorites (Rage, 1984; Rage, 2016). The length of the humerus (five mm) suggests that the individual measured about 18–20 mm in snout-vent length.

To further investigate the ecology of the animal, we studied the microanatomy of the femur, through a transverse virtual section of the diaphysis on tomograms, and calculated its compactness profile with the software Bone Profiler (Girondot & Laurin, 2003). Without much surprise, both inference models (based on backward elimination and forward selection procedures, respectively) presented by Laurin, Canoville & Quilhac (2009) suggest an amphibious or terrestrial lifestyle (see Supplemental Information). This would suggest that P. sigei was not neotenic because all extant neotenic urodeles are strictly aquatic.

Conclusions: 

The only specimen of Phosphotriton sigei represents a peculiar case of exceptional preservation, in which several organs are preserved in three dimensions, in addition to the skeleton: lung, spinal cord, lumbosacral plexus, digestive tract, muscles, and an unidentified urogenital organ. In addition, the alimentary tract contains skeletal remains of a frog, which is a very rare prey for salamanders. Contrary to the above-cited case of arthropods (Schwermann et al., 2016a), we do not believe that the new data on soft anatomy will revolutionize our understanding of lissamphibian evolution, particularly because such characters have played a modest role in phylogenetic studies of lissamphibians. However, these data, such as the presence of a lung, proved critical to place the mummy in the phylogeny, and these data document the oldest known occurrence of anurophagy in urodeles.

Jérémy Tissier​, Jean-Claude Rage and Michel Laurin. 2017. Exceptional Soft Tissues Preservation in A Mummified Frog-eating Eocene Salamander.   PeerJ. 5:e3861.  DOI:  10.7717/peerj.3861

Jérémy Tissier, Jean-Claude Rage, Renaud Boistel, Vincent Fernandez, Nicolas Pollet, Géraldine Garcia and Michel Laurin. 2016. Synchrotron Analysis of A ‘Mummified’ Salamander (Vertebrata: Caudata) from the Eocene of Quercy, France. Zoological Journal of the Linnean Society. 177(1); 147–164.   DOI:   10.1111/zoj.12341

Ancient petrified salamander reveals its last meal
phy.so/426241628 via @physorg_com

---------------------------------------------------------------

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] The Squamation of the Eocene stem-Basilisk Geiseltaliellus maarius (Squamata: Iguanidae: Corytophaninae) from Messel, Germany ---ScRaBBlE

Geiseltaliellus maarius  Smith, 2009

life reconstruction by J. Eberhardt & A. Vogel  (SMF)

Smith, 2017. SALAMANDRA. 53(4) 

Abstract

 An exceptional new specimen of the stem-basilisk Geiseltaliellus maarius from the middle Eocene of Messel, Germany, preserves details of the squamation of this extinct species. The dorsum and extremities were covered by small, rhomoidal scales, about 0.2 mm in size in most places; somewhat larger scales were present on the lower extremities and on the head. Scales of the venter were arranged in transverse rows, unlike in extant Polychrus and Laemanctus. There is some evidence that the scales on the extremities possessed keels, as in extant basilisks and Polychrus. Keratin appears to be preserved in places. The “Oberhäutchen” is nearly featureless, probably the result of postmortem microbial decomposition; scale organs were not observed. Overall, the body of G. maarius possessed a fine, homogeneous squamation most similar to Basiliscus. Possible sexual dimorphism in the form of the parietal crest raises the prospect of a projecting median keel composed of skin in male G. maarius, although direct evidence on this point is currently lacking. The squamation of the tail is discussed in light of the pseudoautotomy shown by this species. 

Key words: Fossils, Corytophanidae, Eocene, scales, keratin.

Figure 1. Skeleton with skin shadows of Geiseltaliellus maarius, SMF ME 11380a (part).
 (A) Detail of temple region of head. (B) Detail of throat or shoulder region. (C) Detail of right lower leg scales (over tibia and fibula). (D) Detail of left lower leg scales (torn downward and preserved around toe). (E) Detail of digit IV of left pes. Scale bar is 5 mm.

Figure 8. Reconstruction of the squamation of male Geiseltaliellus maarius from Messel.

Juliane Eberhardt (SMF) drew the life reconstruction, colored by Anika Vogel (SMF). 

 K. T. Smith. 2017. The Squamation of the Eocene stem-basilisk Geiseltaliellus maarius (Squamata: Iguanidae: Corytophaninae) from Messel, Germany. SALAMANDRA. 53(4); 519–530.  

http://www.salamandra-journal.com/index.php/home/contents/2017-vol-53/1879-smith-k-t/file

  

---------------------------------------------------------------

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 • 2018] A North American Stem Turaco, and the Complex Biogeographic History of Modern Birds ---ScRaBBlE

Field & Hsiang, 2018.

 DOI: 10.1186/s12862-018-1212-3

bird images by International Touraco Society

blogs.BioMedCentral.com

Abstract

Background: 

Earth’s lower latitudes boast the majority of extant avian species-level and higher-order diversity, with many deeply diverging clades restricted to vestiges of Gondwana. However, palaeontological analyses reveal that many avian crown clades with restricted extant distributions had stem group relatives in very different parts of the world.

Results:

Our phylogenetic analyses support the enigmatic fossil bird Foro panarium Olson 1992 from the early Eocene (Wasatchian) of Wyoming as a stem turaco (Neornithes: Pan-Musophagidae), a clade that is presently endemic to sub-Saharan Africa. Our analyses offer the first well-supported evidence for a stem musophagid (and therefore a useful fossil calibration for avian molecular divergence analyses), and reveal surprising new information on the early morphology and biogeography of this clade. Total-clade Musophagidae is identified as a potential participant in dispersal via the recently proposed ‘North American Gateway’ during the Palaeogene, and new biogeographic analyses illustrate the importance of the fossil record in revealing the complex historical biogeography of crown birds across geological timescales.

Conclusions: 

In the Palaeogene, total-clade Musophagidae was distributed well outside the range of crown Musophagidae in the present day. This observation is consistent with similar biogeographic observations for numerous other modern bird clades, illustrating shortcomings of historical biogeographic analyses that do not incorporate information from the avian fossil record.

Keywords: Biogeography, Palaeontology, Turaco, Musophagidae, Phylogeny, Fossils, Gondwana, Dispersal, Otidimorphae, Macroevolution

Fig. 1 Skeletal morphology of total clade musophagids.
(a) Complete skeleton of Foro panarium holotype USNM 336261. Scale bar equals 10 cm.
(b) 3-dimensional CT rendering of the pectoral region of Ross’s Turaco (Musophaga rossae) GCO 1142 (Georgia College Ornithology, Georgia College and State University, Milledgeville, GA). LF – left ramus of furcula, RC – right coracoid, RF – right ramus of furcula, S – sternum. 153:1 denotes unfused midline of furcula, which optimizes as an unambiguous synapomorphy of a Foro + Musophagidae clade. (c) Pectoral region of F. panarium. LH – left humerus, RS – right scapula. (d) Cranial region of USNM 336261. 50:1 processus costales of axis absent. 152:1 bill short and stout with broad processus maxillaris of the os nasale. (e) Distal end of right leg of USNM 336261. 109:0 – trochlea metatarsi IV without large trochlea accessoria. 106:0 tendon of musculus flexor hallucis longus not enclosed in bony canal

  

    

Daniel J. Field and Allison Y. Hsiang. 2018. A North American Stem Turaco, and the Complex Biogeographic History of Modern Birds. BMC Evolutionary Biology. 18:102.  DOI: 10.1186/s12862-018-1212-3

Feathered fruit-eater frozen in fossil form - tinyurl.com/ybmtujr9 @BMC_Series

    

---------------------------------------------------------------

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.

[PaleoMammalogy • 2018] Sobrarbesiren cardieli • First Adequately-known Quadrupedal Sirenian from Eurasia (Eocene, Bay of Biscay, Huesca, northeastern Spain) ---ScRaBBlE

Sobrarbesiren cardieli

Díaz-Berenguer, Badiola, Moreno-Azanza & Canudo, 2018

 DOI: 10.1038/s41598-018-23355-w 

Abstract

Sirenians are the only extant herbivorous mammals fully adapted to an aquatic lifestyle. They originated in Africa during the Paleocene from an undetermined clade of afrotherian mammals, and by the end of the Eocene they were widely distributed across the tropical latitudes. Here we introduce Sobrarbesiren cardieli gen. et sp. nov. It is the first adequately-known quadrupedal sirenian from Eurasia and the oldest record of this clade from western Europe. Fossils have been recovered from the middle Lutetian (SBZ15) site of Castejón de Sobrarbe-41 (Huesca, Spain), and comprise many cranial and postcranial remains, including pelvic girdle and hind limb bones, from at least six sirenian individuals of different ontogenetic stages. Sobrarbesiren shows a suite of characters previously considered synapomorphies of different clades of derived sirenians, such as the presence of the processus retroversus of the squamosal and the pterygoid fossa, combined with ancestral characters such as the presence of an alisphenoid canal, a permanent P5, at least two sacral vertebrae, a primitive pelvis and functional femora and fibulae. Sobrarbesiren is recovered as the sister taxon of Dugongidae and represents a transitional stage of adaptation to aquatic life between the amphibious quadrupedal prorastomids and the aquatic quadrupedal protosirenids.

Figure 2 Skull of Sobrarbesiren cardieli gen. et sp. nov. (holotype, MPZ 2017/1), in lateral view. (a) Photograph, (b) interpretative sketch. Sutures are marked with plain lines; dashed lines represent reconstructed sutures; shaded areas represent broken or badly preserved bones; and dotted areas represent matrix.

Anatomical abbreviations: ac, alisphenoid canal; as, alisphenoid; bo, basioccipital; bs, basisphenoid; eam, external auditory meatus; eo, exoccipital; fio, infraorbital foramen; fm, foramen magnum; fr, frontal; j, jugal; lc, lacrimal; lcf, lacrimal foramen; mf, mesorostral fossa; mx, maxilla; n, nasal; nc, nuchal crest; oc, occipital condyle; pa, parietal; pal, palatine; paop, paraoccipital process; pmx, premaxilla; pt, pterygoid; ptp, post-tympanic process; so, supraoccipital; sop, supraorbital process of frontal; sq, squamosal; tc, temporal crest; zps, zygomatic process of squamosal.

Systematic palaeontology

Class Mammalia Linnaeus, 1758

Superorder Afrotheria Stanhope et al., 1998

Mirorder Tethytheria McKenna, 1975

Order Sirenia Illiger, 1811

Family uncertain

Sobrarbesiren cardieli gen. et sp. nov.

Etymology: In reference to the Sobrarbe region (Huesca, northeastern Spain), and in honour of Jesús Cardiel Lalueza, who discovered the fossil site.

Holotype: MPZ 2017/1 a complete skull of a subadult individual which preserves alveoli of P1-4, a complete left P5, and M1-3 on both sides (Figs 2, 3, 4a,b,g,h and 5). The specimen is housed in the Museo de Ciencias Naturales de la Universidad de Zaragoza (MPZ) (Zaragoza, Spain). S. cardieli is the type species of the genus by monotypy and by original designation.

Figure 4 Skull of Sobrarbesiren cardieli gen. et sp. nov. (holotype, MPZ 2017/1), in ventral view and dentition (holotype, MPZ 2017/1 and MPZ 2017/4, MPZ 2017/5). (a,b) Skull (MPZ 2017/1) in ventral view. (a) Photograph, (b) interpretative sketch. For anatomical abbreviations see Fig. 2. (c,d) ?I1 (MPZ 2017/4) in lingual (c) and occlusal (d) views. (e,f) ?I3 (MPZ 2017/5) in lateral (e) and occlusal (f) views. (g,h) Left dental arcade of the holotype skull (MPZ 2017/1). (g) Photograph, (h) interpretative sketch. Sutures are marked with plain lines; dashed lines represent reconstructed sutures; and dotted areas represent matrix.

Dental anatomical abbreviations: ac, anterior cingular cusp; acc, anterior accessory cusp; acl, anterior cingulum; hy, hypocone; Lac, labial cusp; lac, lingual cusp; lcl, lingual cingulum; mc, main cusp; mcl, metaconule; me, metacone; pa, paracone; pc, posterior cingular cusp; pcc, posterior accesory cusp; pcl, posterior cingulum; pcv, posterior cingular valley; pr, protocone; prl, protoconule; tv, transverse valley.

Locality and horizon: Only known from the Castejón de Sobrarbe-41 fossil site (CS-41), in Castejón de Sobrarbe, Huesca, Ainsa Basin in the southern Pyrenees, Sobrarbe Formation (middle Lutetian, early middle Eocene)21 (Fig. 1b).

Diagnosis: (Ch. Character state following the descriptions and numbering sequence of Domning (1994) as updated by Vélez-Juarbe et al. (2014) and Springer et al. (2015) (e.g., Ch. 102 (0) refers to state 0 of character 102)): sirenian, based on the following synapomorphies: retracted and enlarged external nares (Ch. 8 (1)); premaxilla contacts the frontals (Ch. 9 (1)); and a P1-5, M1-3 postcanine dental formula (Ch. 155 (1)); and characterized by the following combination of characters (autapomorphies highlighted with*): upper dental formula 2.1.5.3 (I2 absent); pterygoid fossa present, extending above the level of the roof of the internal nares (Ch. 102 (1)); alisphenoid canal present (Ch. 101 (0)); rectangular and elongated basioccipital* (Fig. 4a,b and Supplementary Information Fig. S1a); hook-shaped acromion process of the scapula* (Fig. 7d), which extends just to the dorsal border of the glenoid fossa* (Fig. 7b); posterior iliac spine of the innominate bone present* (Fig. 9c); lateral iliac spine that appears abruptly on the lateral surface of the ilium with a flattened ventrolateral surface* (Fig. 9e).

Figure 10 Reconstructed composite skeleton of Sobrarbesiren cardieli gen. et sp. nov. Shaded elements represent the fossils studied.

Conclusions: 

We describe a new stem sirenian species, Sobrarbesiren cardieli, from the early middle Eocene (Lutetian, SBZ15) of the southern Pyrenees. This is the first adequately known quadrupedal sirenian from the northeastern Atlantic coast (Bay of Biscay, Spain) and the oldest sirenian from western Europe. It is represented by three skulls, cervical, dorsal, lumbar, sacral and caudal vertebrae, complete anterior, middle and posterior ribs, four scapulae, two hemipelvises, and fore and hind limb bones. This large collection of skeletal elements in different ontogenetic stages constitutes the most complete sample of an early middle Eocene sirenian in the Old World. Our phylogenetic analyses place Sobrarbesiren cardieli most parsimoniously as the sister taxon of a paraphyletic Dugongidae, which gives rise to Trichechidae. Sobrarbesiren is the only Eurasian sirenian that preserves terrestrially-functional pelvic girdle and hind limb bones. These indicate an intermediate state of adaptation to the aquatic lifestyle between other groups of quadrupedal sirenians, (namely the plesiomorphic pelvis and hind limbs of prorastomids, versus the slightly more derived limbs of the protosirenids). A further study of the functional morphology of sirenian hind limbs may be one of the keys to understanding the first stages of adaptation to aquatic life by these marine mammals.

Ester Díaz-Berenguer, Ainara Badiola, Miguel Moreno-Azanza and José Ignacio Canudo. 2018. First Adequately-known Quadrupedal Sirenian from Eurasia (Eocene, Bay of Biscay, Huesca, northeastern Spain). Scientific Reports. 8, Article number: 5127. DOI: 10.1038/s41598-018-23355-w

 twitter.com/inarvaezp/status/977228936701718528

---------------------------------------------------------------

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.