Macro-invertébrés du Cénomanien du Djebel Metrassi (Batna, NE Algérie): Systématique et biostratigraphie

A rich paleontological assemblage was collected in the Cenomanian deposits of the Djebel Metrassi (Batna, NE Algeria). It consists of 327 specimens assigned respectively to a single coral, 24 bivalve, 14 gastropod, 3 ammonite, and 7 echinoid species. This macrofaunal association leads us to establish an original taxonomical reference list along with several species new for the Cenomanian of this area, and supports the lithostratigraphic framework herein proposed.[fr] Un assemblage paléontologique a été récolté dans le Cénomanien du Djebel Metrassi (Batna, NE Algérie). Constitué de 327 spécimens, il comporte un corail, 24 espèces de bivalves, 14 espèces de gastéropodes, 3 espèces d’ammonites et 7 espèces d’échinides. Cet assemblage permet d’établir une liste systématique originale, avec des espèces inédites, pour le Cénomanien de ce Djebel et vient soutenir le découpage lithostratigraphique proposé

Middle–Upper Jurassic marine gastropods from central Saudi Arabia

A total of 68 gastropod specimens are reported from the Middle‒Upper Jurassic sedimentary successions exposed at central Saudi Arabia. The studied material comes from the Tuwaiq Mountain and Hanifa formations at the Khashm al Qaddiyah, Dirab, Jabal al Abakkayn and Maáshabah sections. Thirteen species are identified, described and illustrated. Among them, a new Aporrhais species (A. sauditica sp. nov.) is introduced. In addition, two further possible new Pseudomelania species from the same strata are mentioned. Other members of the assemblage include Kosmomphalus? sp. aff. K. reticulatus Fischer, Bourguetia? sp. aff. B. saemanni (Oppel), Bourguetia? sp., Ampullospira sp., Globularia? sp. cf. G. bajociana Fischer, Purpuroidea sp. aff. P. glabra Morris and Lycett, Purpuroidea sp., Cossmannea sp. aff. C. desvoidyi (d’Orbigny), Cryptoplocus sp. aff. C. depressus (Voltz) and Actaeonina? sp. Stratigraphically, seven species of this gastropod assemblage were only reported from the Middle Jurassic, whereas the other six ones are extending from the Middle to the Upper Jurassic of the studied succession. As compared with their gastropod content, the Khashm al Qaddiyah represents the richest section (33 out of 68 specimens, 48.5%), whereas the Maáshabah section showed an impoverished gastropod assemblage (only three specimens, 4.4%). The species reported here show paleobiogeographical affinities with coeval gastropod assemblages from India, east Africa, Middle East (Israel, the Sinai of Egypt) and western Tethys. The identified species confirm three depositional settings: open shelf lagoon, shoal/fore-shoal and open marine environments. The lower degree of fragmentation, poor sorting and scarcity of abrasion indicate a parautochthonous faunal assemblage.Fil: Ferrari, Silvia Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; ArgentinaFil: El-Hedeny, Magdy. Alexandria University; Egipto. King Saud University; Arabia SauditaFil: Zakhera, Mohamed. Aswan University; Egipto. Najran University; Arabia SauditaFil: El-Sabbagh, Ahmed. Alexandria University; EgiptoFil: Al Farraj, Saleh. King Saud University; Arabia Saudit

Cenomanian–Turonian rudist (bivalvia) lithosomes from NW of Jordan

Two rudist lithosomes characterized by high abundance but low in diversity are described from five measured-stratigraphic sections in the Upper Cretaceous Hummar and Wadi As Sir Limestone Formations in the Ajlun and Kitim areas, in NW Jordan. The caprinid lithosome from the Hummar Formation is characterized by abundant occurrences of canaliculate rudists such as Caprinula boissyi d'Orbigny, 1840, Neocaprina nanosi Plenfcar, 1961, Caprina sp. (aff. schiosensis Boehm, 1892), but rare specimens of radiolitids such as Sauvagesia sharpei (Bayle, 1857), Sauvagesia/Durania sp. and Eoradiolites sp., along with requienids (Apricardia sp.), indicating a late Cenomanian age. The hippuritid lithosome is determined from the stratigraphically higher Wadi As Sir Limestone Formation and it is represented by well-preserved specimens of Hippurites resectus Defrance, 1821 and also some specimens of Vaccinites rousseli Douville, 1894 and Durania arnaudi (Choffat, 1891) indicating a late Turonian age