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Khouribga, Morocco

Vincent P.,Staatliches Museum fur Naturkunde Rosenstein 1 | Bardet N.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Houssaye A.,University of Bonn | Amaghzaz M.,Center Minier Of Khouribga | Meslouh S.,Ministere de LEnergie
Gondwana Research | Year: 2013

Several clades of marine tetrapods, including the apex predators mosasaurs and plesiosaurs, disappeared during the mass extinction at the end of the Cretaceous, about 65. My ago. The extreme fossil richness of the Maastrichtian Phosphates of Morocco provides insights into the systematic diversity of the latest mosasaurs where about ten species are known. However, data of the coeval plesiosaurs are comparatively scarce. Up to now, only one species, the elasmosaurid Zarafasaura oceanis, is known. Here we describe new elasmosaurid plesiosaur post-cranial material from the Maastrichtian of the Oulad Abdoun Basin (Morocco) that provides new data about the taxonomical and morphological diversity of plesiosaurs in this area. Most of the new material consists of vertebrae that likely belong to a unique elasmosaurid taxon and differ from all other elasmosaurids documented so far. As Zarafasaura is known only from cranial material, it cannot be determined whether the new material may be assigned to this taxon. The new material shows that the latest Cretaceous plesiosaurs in this low latitude area (about 20°N) were rather gracile, most likely piscivorous taxa that occupied ecological niches similar to those of rather small mosasaurs (e.g., Halisaurus and ". Platecarpus" ptychodon) but distinct from those of most coeval large mosasaur taxa. These plesiosaur fossils are also remarkable in that they consist of both juvenile and adult specimens, suggesting limited segregation between individuals of different ontogenetic stages, a feature that might be attributed to upwelling-related, high nutrient input and food availability in this area during the Maastrichtian. Moreover, the possible occurrence, with older specimens, of a neonate specimen - one among the very few known worldwide - suggests a possible social structure organization. The new data contribute to increase our understanding of Late Cretaceous plesiosaur biodiversity and provide new insights into the ecology of latest Cretaceous marine apex predators. © 2012 International Association for Gondwana Research. Source

Houssaye A.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Houssaye A.,University of Bonn | Rage J..-C.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Bardet N.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | And 3 more authors.
Palaeontology | Year: 2013

Palaeophis maghrebianus belongs to the Palaeophiinae (Palaeophiidae). This snake subfamily is relatively poorly known, and it is mainly represented by disarticulated vertebrae and ribs and by a few vertebral segments. Its intracolumnar variability remains also poorly understood. The discovery of new isolated vertebrae and vertebral segments of Palaeophis maghrebianus in the Ypresian (Lower Eocene) Phosphates of Morocco enables us to provide a more detailed diagnosis of this species and to describe its intracolumnar variability. Moreover, the new material reveals that this species could reach gigantic size being, with Palaeophis colossaeus, one of the two longer palaeophiids. The microanatomical and histological analysis of some vertebrae illustrating diverse positions along the vertebral column reveals the presence of osteosclerosis, especially in the anterior and mid-precloacal regions. The occurrence of this osseous specialization implies a role in buoyancy and body trim control in this taxon, which is considered a shallow marine dweller based on its anatomical features and geological data. Palaeophis maghrebianus also displays a dense vascular network suggesting a growth speed, and thus a metabolic rate, much higher than in the biggest extant snakes. © The Palaeontological Association. Source

De Lapparent de Broin F.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Bardet N.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Amaghzaz M.,Center Minier Of Khouribga | Meslouh S.,MEMEE
Comptes Rendus - Palevol | Year: 2014

A new genus and species of huge marine turtle (superfamily Chelonioidea, epifamily Dermochelyoidae) is described from the Maastrichtian Phosphates of the Oulad Abdoun Basin of Morocco. A new type of feeding apparatus, adapted for a powerful crushing pattern, illustrates the noteworthy diversity of fossil vertebrates of the Maastrichtian-Ypresian Phosphates of Morocco. No other crushing cryptodire or bothremydid pleurodire has this morphology. During the Maastrichtian, the known crushing pattern of chelonioids was different, close to that of modern cheloniids, as illustrated in Morocco in the Maastrichtian Ganntour Basin and the Palaeogene Oulad Abdoun Basin. This new taxon exhibits unusual cranial characters (fusion of premaxillae associated with a backward and dorsal retraction of the naris, horizontal stretching of the dorsal meatus quadrati), that are shared only with another new turtle, known also from the same Maastrichtian Phosphates of Morocco. © 2013 Académie des sciences. Source

Bardet N.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Jalil N.-E.,Cadi Ayyad University | de Lapparent de Broin F.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Germain D.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | And 2 more authors.
PLoS ONE | Year: 2013

Background:Secondary adaptation to aquatic life occurred independently in several amniote lineages, including reptiles during the Mesozoic and mammals during the Cenozoic. These evolutionary shifts to aquatic environments imply major morphological modifications, especially of the feeding apparatus. Mesozoic (250-65 Myr) marine reptiles, such as ichthyosaurs, plesiosaurs, mosasaurid squamates, crocodiles, and turtles, exhibit a wide range of adaptations to aquatic feeding and a broad overlap of their tooth morphospaces with those of Cenozoic marine mammals. However, despite these multiple feeding behavior convergences, suction feeding, though being a common feeding strategy in aquatic vertebrates and in marine mammals in particular, has been extremely rarely reported for Mesozoic marine reptiles.Principal Findings:A relative of fossil protostegid and dermochelyoid sea turtles, Ocepechelon bouyai gen. et sp. nov. is a new giant chelonioid from the Late Maastrichtian (67 Myr) of Morocco exhibiting remarkable adaptations to marine life (among others, very dorsally and posteriorly located nostrils). The 70-cm-long skull of Ocepechelon not only makes it one of the largest marine turtles ever described, but also deviates significantly from typical turtle cranial morphology. It shares unique convergences with both syngnathid fishes (unique long tubular bony snout ending in a rounded and anteriorly directed mouth) and beaked whales (large size and elongated edentulous jaws). This striking anatomy suggests extreme adaptation for suction feeding unmatched among known turtles.Conclusion/Significance:The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods. This new taxon exemplifies the successful systematic and ecological diversification of chelonioid turtles during the Late Cretaceous. This new evidence for a unique trophic specialization in turtles, along with the abundant marine vertebrate faunas associated to Ocepechelon in the Late Maastrichtian phosphatic beds of Morocco, further supports the hypothesis that marine life was, at least locally, very diversified just prior to the Cretaceous/Palaeogene (K/Pg) biotic crisis. © 2013 Bardet et al. Source

Kocsis L.,University of Lausanne | Gheerbrant E.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | Mouflih M.,Faculte des science Ben Msik | Cappetta H.,Montpellier University | And 2 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2014

Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous-early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils - shark tooth enameloid and dentine, and coprolites - show large range in δ13C values from -14 to +6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling.The large variation in δ18OPO4 values of the shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0'). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian-early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian.The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian-early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.© 2013 Elsevier B.V. Source

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