Dinosaur footprints and other Ichnofauna from the Cretaceous Kem Kem Beds of Morocco

We describe an extensive ichnofossil assemblage from the likely Cenomanian-age 'lower' and 'upper' units of the 'Kem Kem beds' in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundant footprints from theropod dinosaurs. Sauropod and ornithischian footprints are much rarer, similar to the record for fossil bone and teeth in the Kem Kem assemblage. The upper unit also preserves a variety of invertebrate traces including Conichnus (the resting trace of a sea-anemone), Scolicia (a gastropod trace), Beaconites (a probable annelid burrow), and subvertical burrows likely created by crabs for residence and detrital feeding on a tidal flat. The ichnofossil assemblage from the Upper Cretaceous Kem Kem beds contributes evidence for a transition from predominantly terrestrial to marine deposition. Body fossil and ichnofossil records together provide a detailed view of faunal diversity and local conditions within a fluvial and deltaic depositional setting on the northwestern coast of Africa toward the end of the Cretaceous

An Early Cretaceous vertebrate assemblage from the Cabao Formation of NW Libya

Fossil vertebrates from the Cabao Formation discovered in the area of Nalut in northwestern Libya include the hybodont shark Priohybodus, the crocodilian Sarcosuchus, an abelisaurid, a baryonichine spinosaurid and a large sauropod with spatulate teeth. The Cabao Formation may be Hauterivian to Barremian in age, although an earlier Berriasian to Valanginian age cannot be excluded. Its dinosaur assemblage is reminiscent of that of the El Rhaz and Tiouraren formations of Niger and strongly differs from both the Cenomanian assemblages of Morocco and Egypt and the Late Aptian to Albian fauna of Tunisia. Fossil vertebrates may be an important tool to establish the stratigraphical framework of the poorly dated Early Cretaceous continental deposits of Afric

Les Aeduellidae (Pisces, Actinopterygii) carbonifères et permiens : systématique et étude phylogénétique préliminaire

Les genres et espèces d’aeduellidés actuellement connus sont présentés. Une analyse phylogénétique, impliquant 12 autres actinoptérygiens et un porolépiforme comme groupe extérieur, confirme que les Aeduellidae constituent un groupe naturel. Mais les relations de parenté de ses taxons, dont un genre, Bourbonnella, apparaît comme paraphylétique, ne sont pas entièrement éclaircies, probablement en raison du nombre de données manquantes. Cette famille présente une mosaïque de caractères plésiomorphes et apomorphes pour les actinoptérygiens. Les relations phylogénétiques des Aeduellidae avec les autres Actinopteri basaux (= Palaeoniscimorpha) ne sont pas non plus éclaircies. En effet l’analyse ne révèle pas d’affinités particulières avec les groupes avec lesquels on avait tenté de les rapprocher par le passé.The aeduellid genera and species already known are presented. A phylogenetic analysis, involving 12 other actinopterygians and a porolepiform outgroup, confirms that the Aeduellidae are a natural group. But their interrelationships are not cleared up completely, probably because of many missing data; in particular one genus, Bourbonnella, appears as paraphyletic. This family has a mosaic of plesiomorphic and apomorphic actinopterygian characters; their relationships with the other basal Actinopteri (= Palaeoniscimorpha) are not clearer. In fact the analysis does not show particular affinities with the groups with which they have been tentively compared in the past.</p

Cycle sédimentaire et vertébrés d'une formation peu connue du Bassin de Paris, l'unité des Sables de Bourguillemont (Oise, France) (Paléocène supérieur)

Dutheil, Didier B., Moreau, Fabrice, Delhaye-Prat, Vincent (2002): Cycle sédimentaire et vertébrés d'une formation peu connue du Bassin de Paris, l'unité des Sables de Bourguillemont (Oise, France) (Paléocène supérieur). Geodiversitas 24 (4): 753-764, DOI: http://doi.org/10.5281/zenodo.537753

Trace Elemental Imaging of Rare Earth Elements Discriminates Tissues at Microscale in Flat Fossils

The OT1 ConsortiumInternational audienceThe interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies

Synchrotron x-ray fluorescence imaging discriminates fossil tissues

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Dinosaur Footprints and Other Ichnofauna from the Cretaceous Kem Kem Beds of Morocco

We describe an extensive ichnofossil assemblage from the likely Cenomanian-age ‘lower’ and ‘upper’ units of the ‘Kem Kem beds’ in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundant footprints from theropod dinosaurs. Sauropod and ornithischian footprints are much rarer, similar to the record for fossil bone and teeth in the Kem Kem assemblage. The upper unit also preserves a variety of invertebrate traces including Conichnus (the resting trace of a sea-anemone), Scolicia (a gastropod trace), Beaconites (a probable annelid burrow), and subvertical burrows likely created by crabs for residence and detrital feeding on a tidal flat. The ichnofossil assemblage from the Upper Cretaceous Kem Kem beds contributes evidence for a transition from predominantly terrestrial to marine deposition. Body fossil and ichnofossil records together provide a detailed view of faunal diversity and local conditions within a fluvial and deltaic depositional setting on the northwestern coast of Africa toward the end of the Cretaceous.</p