[Paleontology • 2017] Cascolus ravitis • A New Crustacean from the Herefordshire (Silurian) Lagerstätte, UK , and Its Significance in Malacostracan Evolution ---ScRaBBlE

Cascolus ravitis 

Siveter, Briggs, Siveter, Sutton & Legg, 2017  

 DOI: 10.1098/rspb.2017.0279 

Abstract

Cascolus ravitis gen. et sp. nov. is a three-dimensionally preserved fossil crustacean with soft parts from the Herefordshire (Silurian) Lagerstätte, UK. It is characterized by a head with a head shield and five limb pairs, and a thorax (pereon) with nine appendage-bearing segments followed by an apodous abdomen (pleon). All the appendages except the first are biramous and have a gnathobase. The post-mandibular appendages are similar one to another, and bear petal-shaped epipods that probably functioned as a part of the respiratory–circulatory system. Cladistic analysis resolves the new taxon as a stem-group leptostracan (Malacostraca). This well-preserved arthropod provides novel insights into the evolution of appendage morphology, tagmosis and the possible respiratory–circulatory physiology of a basal malacostracan.

An international team of scientists led by the University of Leicester has discovered a new 430 million-year-old fossil and has named it in honour of Sir David Attenborough - who grew up on the University campus.  

Systematic palaeontology

Phylum Arthropoda
Subphylum Crustacea

Class Malacostraca
Subclass Phyllocarida

Order Leptostraca

Genus Cascolus gen. nov.

Type species: Cascolus ravitis sp. nov.

Etymology: The new crustacean is named in honour of the naturalist and broadcaster Sir David Attenborough, who grew up on University College Leicester campus, in celebration of his 90th birthday. Latin castrum ‘stronghold’ and colus ‘dwelling in’; alluding to the Middle/Old English source for the surname ‘Attenborough, derived from atten ‘at the’ and burgh ‘a fortified place’. Latin Ratae, the Roman name for Leicester, vita ‘life’ and commeatis ‘a messenger’.


  Diagnosis of genus (monotypic) and species: An elongate body comprising a head with a head shield, pedunculate eyes and five limb pairs; and a trunk consisting of a thorax (pereon) with nine limb-bearing segments and an apodous abdomen (pleon). The first appendage is uniramous and has three slender flagella longer than the body. All other appendages are biramous and have a gnathobase. The post-mandibular appendages are similar to one another, except that the fourth head appendage bears a single petal-shaped epipod, and the fifth head appendage and each trunk appendage bear two petal-shaped epipods.

  Material: Only known from the holotype OUMNH C.29698 (figure 1v), a specimen with soft parts reconstructed in three dimensions (figure 1a–u).

  Locality and horizon: Herefordshire, England, UK; Wenlock Series, Silurian.


David J. Siveter, Derek E. G. Briggs, Derek J. Siveter, Mark D. Sutton and David Legg. 2017. A New Crustacean from the Herefordshire (Silurian) Lagerstätte, UK, and Its Significance in Malacostracan Evolution. Proceedings of the Royal Society B.  DOI: 10.1098/rspb.2017.0279 

 430 million-year-old fossil named in honor of Sir David Attenborough
 http://phy.so/409322871   @physorg_com

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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.