Dinosaur mines of the Kem Kem

The nice transgressions that occurred within the mid a part of the Cretaceous have had a profound affect on the geology of many elements of the world. In North America, the seas flooded the central a part of the continent to supply the Western Interior Seaway, whereas, in northern Europe, the incoming of the Chalk seas noticed a lot of the continent disappearing under the waves. Across the northern a part of Africa, the transgression was extra gradual, however on a scale as giant as that seen anyplace else. In the interval previous the good marine flooding, large coastal plains developed throughout an enormous tract of land that extends from what’s now Niger to Egypt. These coastal plains have been criss-crossed by nice braided river methods and offered the right habitat for an enormous vary of recent water and terrestrial animals.

Vertebrate fossils have been recognized from the coastal plain, fluvial rocks of the African Cretaceous for a very long time; excavations in Egypt in 1912 recovered the stays of a number of species, together with the weird theropod, Spinosaurus. Subsequent expeditions to different areas of north and northwest Africa have yielded many further species of dinosaurs, in addition to a number of different fossils.

In the early Nineteen Nineties, the southeastern a part of Morocco was simply beginning to confide in tourism and, with it, the good geological wealth of the area was turning into higher recognized. In addition to the wealthy and numerous fossil faunas from the sandstones and limestones of the Palaeozoic, fossils have been beginning to be found within the Cretaceous rocks that unconformably overlie the older successions. This unconformable sequence is most readily seen at Hassi Begaa located about ten miles south Taouz, the place it varieties the good Kem Kem escarpment.

The Cretaceous escarpments that type the north-japanese and southern margins of the Palaeozoic rocks in southeast Morocco comprise two fundamental rock models: the fluvial sandstones of the Ifezouane and Aoufous Formations, and the marine and lagoonal limestones of the Akrabou Formation. The former are of unsure age, however in all probability span the higher a part of the Albian and a lot of the Cenomanian, whereas the latter include ammonites indicative of Late Cenomanian and Turonian age. Although a lot of the succession alongside a lot of the escarpment is sparingly fossiliferous, there are a number of websites and stratigraphic ranges which have produced distinctive faunas. The majority of the Akrabou Formation limestones have been deposited in extraordinarily shallow water and include solely low variety beds of oysters and gastropods. However, some extra marine intervals yield very ample and nicely-preserved echinoids, whereas a mattress of huge concretions uncovered close to the city of Goulmima has yielded ample giant ammonites in addition to skeletons of fish and marine reptiles. In addition, the current discovery of a mattress of laminated limestone with superbly preserved fish skeletons has yielded many a whole lot of small, however lovely specimens.

However, it’s the fluvial a part of the succession that has turn out to be justifiably well-known for its fossils. Although typically obscured under fallen limestone blocks or desert sand, and typically seen solely to show unfossiliferous mudstones, the purple beds of the decrease a part of the escarpment have produced huge numbers of vertebrate fossils and these now furnish museums and fossil outlets throughout the globe. The high quality of those fossils was first recognised in 1991, when the primary fish bones have been discovered by a sheep herder from the small desert village of Hassi Begaa. Later, some wonderful cranial materials from the dinosaur, Carcharodontosaurus (first found in 1927 by Charles Depéret and C Savornin in Algeria), have been discovered within the area by Paul Sereno in 1995. As the fossils are current in rocks occurring on steep cliff faces and are largely confined to conglomerates on the base of huge river channel fills, it was quickly realised that solely restricted fossils might be discovered on the floor and most materials might solely be extracted by tunnelling into the rock face. This technique of amassing fossils is tough, particularly as solely hand instruments are used and water needs to be carried to the location on this arid and very harmful space, with a number of individuals having been killed by shaft collapses. (See Issues sixteen, Tunnelling for dinosaurs within the High Arctic, by Dr TH Rich and Issue 22, Hell and excessive water: the digs of Dinosaur Cove, by Robyn Molan, for extra on dinosaur mining.) Despite the hazards, this can be a poor a part of Morocco and there’s good cash to be made out of fossils.

The fossils inside the channel lags are sometimes current as remoted bones they usually differ from virtually pristine preservation to rounded bone pebbles. There has in all probability been a point of sorting inside the fossil beds and the coarse grained sandstone matrix counts towards the preservation and assortment of small and delicate bones. Each channel seems to have a barely totally different fauna, though the general construction of the assemblage appears to be comparable. There are fossils of aquatic, amphibious and terrestrial animals current, all of that are incessantly discovered. The commonest of the aquatic fossils are the barbed rostral tooth, together with fragments from the podium and vertebrae, of the massive sclerorhynchid sawfish, Onchopristis. Alongside these are bones, tooth and scales of quite a lot of fish, with tooth of lungfish being particularly attribute. More full fish skulls and shark tooth are additionally recognized, however are uncommon.

Amphibious reptiles, within the type of turtles, and enormous and small crocodiles, are additionally widespread. These are often discovered as remoted scutes and bones, however properly-preserved skulls are recognized from each teams and shed crocodile tooth are sometimes ample.

Terrestrial fossils are largely restricted to dinosaurs and, in contrast to virtually all different recognized dinosaur websites, are virtually totally composed of the stays of carnivorous theropods, with sauropod stays being very uncommon as compared. Both giant and small theropods are current, with the most typical fossils being remoted tooth, however postcranial bones and elements of the cranium are additionally recorded. The giant theropod tooth are sometimes referred both to Carcharodontosaurus (with giant serrated tooth) or Spinosaurus (with elongate, virtually crocodile-like tooth), however it’s potential that different genera are current, however unrecognised. Careful examination of the smaller bones and most slender tooth reveals that pterosaurs are additionally current inside the assemblage and their tooth are under no circumstances uncommon.

The bias in the direction of carnivores proven by the Kem Kem fossils is extraordinarily uncommon and isn’t merely a set bias. What have been the theropods consuming? It seems that the one meals out there to them have been the aquatic types, so was this space a spot the place theropods congregated to feed on fish in the course of the dry season or throughout a spawning migration? There definitely is proof that Spinosaurus might have been amphibious. However, this can in all probability stay unanswered till we all know extra concerning the fauna and the palaeoenvironment of the location.

Finding dinosaurs within the desert might look like a distant risk for many individuals, however, in actuality, the Kem Kem is sort of straightforward to get to, so long as you’re with somebody who is aware of what they’re doing. It can simply be included right into a journey itinerary by means of japanese Morocco, taking within the mountains and sand seas of the Atlas Mountains and Merzouga, and in addition the Jurassic and Palaeozoic fossils of the Atlas and Anti-Atlas respectively for which this area is so well-known.

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Filed beneath: dinosaurs, fossils Tagged: Carcharodontosaurus, Dinosaur, dinosaur fossils, dinosaurs, fossils, Kem Kem, Morocco, Morocco Fossils, Onchopristis, Spinosaur
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