Reptilian assemblages from the latest Cretaceous - Palaeogene phosphates of Morocco: from Arambourg to present time (original) (raw)
Related papers
First Record of a Tylosaurine Mosasaur from the Latest Cretaceous Phosphates of Morocco
Open Journal of Geology, 2022
The latest Cretaceous Phosphates of Morocco preserve the highest biodiversity of mosasaurid squamates anywhere in the world. Intensive sampling over the past century has uncovered at least ten genera and thirteen species from the mosasaur subgroups Halisauromorpha, Plioplatecarpinae, and Mosasaurinae. Notably missing from the assemblage are members of the macropredatory Tylosaurinae. The Tylosaurinae were globally rare in the Maastrichtian and their apparent absence has been previously explained by either collecting bias, ecological preference for deeper waters, or habitat restriction to higher paleolatitudes. Here, we describe a new tylosaurine mosasaurid, Hainosaurus boubker sp. nov., based on several partial skulls and isolated teeth originating from the Couche III layer of the Sidi Chennane Phosphate quarry near Oued Zem, Morocco. It is unique amongst tylosaurine mosasaurids in possessing blade-like teeth that are laterally compressed, encircled by enamel facets, and differentiated along the dental margin. The discovery of this new taxon in the Maastrichtian of Morocco is remarkable as it represents both the youngest species of Tylosaurinae and the first occurrence in North Africa.
Vertebrate assemblages from the early Late Cretaceous of southeastern Morocco: An overview
Fossils of vertebrates have been found in great abundance in the continental and marine early Late Cretaceous sediments of Southeastern Morocco for more than 50 years. About 80 vertebrate taxa have so far been recorded from this region, many of which were recognised and diagnosed for the first time based on specimens recovered from these sediments. In this paper, we use published data together with new field data to present an updated overview of Moroccan early Late Cretaceous vertebrate assemblages. The Cretaceous series we have studied encompasses three Formations, the Ifezouane and Aoufous Formations, which are continental and deltaic in origin and are often grouped under the name ‘‘Kem Kem beds”, and the Akrabou Formation which is marine in origin. New field observations allow us to place four recognised vertebrate clusters, corresponding to one compound assemblage and three assemblages, within a general temporal framework. In particular, two ammonite bioevents characterise the lower part of the Upper Cenomanian (Calycoceras guerangeri Zone) at the base of the Akrabou Formation and the upper part of the Lower Turonian (Mammites nodosoides Zone), that may extend into the Middle Turonian within the Akrabou Formation, and allow for more accurate dating of the marine sequence in the study area. We are not yet able to distinguish a specific assemblage that characterises the Ifezouane Formation when compared to the similar Aoufous Formation, and as a result we regard the oldest of the four vertebrate ‘‘assemblages” in this region to be the compound assemblage of the ‘‘Kem Kem beds”. This well-known vertebrate assemblage comprises a mixture of terrestrial (and aerial), freshwater and brackish vertebrates. The archosaur component of this fauna appears to show an intriguingly high proportion of large-bodied carnivorous taxa, which may indicate a peculiar trophic chain, although collecting biases alter this palaeontological signal. A small and restricted assemblage, the OT1 assemblage, possibly corresponds to a specific, localised ecosystem within the Kem Kem beds compound assemblage. Microfossils and facies from the Aoufous Formation, corresponding to the top of the compound assemblage, provide evidence of extremely abiotic conditions (hypersalinity), and thus of great environmental instability. At the base of the Akrabou Formation the first ammonite bioevent, Neolobites, corresponds to the onset of the marine transgression in the early Late Cenomanian while the Agoult assemblage (Late Cenomanian?) contains a variety of small fish species that have Central Tethyan affinities. Finally, the youngest Mammites bioevent in the late Early Turonian corresponds to a deepening of the marine environment: this sequence is isochronous with the Goulmima assemblage, a diverse collection of fish and other marine taxa, and shows affinities with taxa from the South Atlantic, the Central Tethys and the Western Interior seaway of North America, and further highlights the biogeographical importance of these North African Late Cretaceous assemblages.
2015
espanolSe describen dos huellas crocodyliformes de “les couches rouges” del Jurasico Medio del Alto Atlas de las que se destaca su importancia por su escasez en el registro mundial. Las huellas no son comparables con los icnogeneros descritos hasta ahora. La huella del pie es incompleta. Suponemos que es un crocodiliforme continental porque el ambiente sedimentario en el que estan las icnitas es fluvial. Finalmente se indica, aunque con unos margenes de inseguridad amplios, el orden de tamano que suponemos para el autor de las pisadas. EnglishTwo Crocodyliform footprints from "les couches rouges" of the Middle Jurassic of the High Atlas are described.We highlight it for its scarcity in the global record. Footprints cannot be compared with other known ichnogenus. The pes print is incomplete.We assume that it is a continental crocodyliform because the footprints are in fluvial deposits. Finally there follows, although with wide margins of uncertainty, the size that we assume...