The fossil prehistoric bony fish cranium element is both rare, well persevered and in a very good conserved state post preparatory work in a U.K. based laboratory. This cranial section has similarities to the archerfish skull, inasmuch as the vaulted structure could be an indication of a possible tube structure. This needs more study to be established. The upper braincase has the typical red staining colour of the concentrated iron heavy fossil layers of the Kem Kem.T he coarse-grained ferruginous sandstone was formed of different sized consolidated matrix grains, this was cleaned off the bone, as matrix obscured the fine bone details of the cranium plate.
The average body length of the bony fish was in the region of 100 centimetres. Many bony parts are found in the Taouz oases formation, however, the roof of the skull is a rare find, being such a fragile skeletal fossil bone, it is rarely found articulated. The illustrations above show the colour and preservation of the cranium element.
From this regions fossil beds come some of the renowned finds of recent times. The likes of the mighty theropod Carcharodontosaurus saharicus, the apex-predator of the prehistoric Cretaceous of East Gondwana, Spinosaurus aegypticus the largest semi-aquatic theropod carnivore, the similarly sail or humped backed sauropod Rebbachisaurus, dromaeosaurs, crocodiles and pterosaurs. The fossil beds of the continental intercalaire at the Kem Kem formation lie across the border between Morocco and Algeria. An area of Hamada (raised plateaux), is mined in the upper layers of the continental intercalaire cliff face. Here the indigenous Berber fossil hunters burrow triangularly shaped caves into soft granular rock cliff faces. These often burrows often traverse some distance of several metres into the congealed aggregate sandy red rock, always unshored, without timber or any other supporting device, timber and all else is in short supply in the desert ténéré region of this never-ending landscape of scrubby rock-strewn desert.
Gondwana began to break up in the early Jurassic and the early Cretaceous (about 184 to 132 million years ago) accompanied by massive eruptions of basalt lava, as East Gondwana, comprising Antarctica, Madagascar, India, and Australia, began to separate from Africa. The discovery of this Calamopleurus fish in Morocco which is twinned to the Brazilian Calamopleurus alights to the geographical amalgamation of West Gondwana by continental collision during the Brasiliano/Pan-African orogenies. A great study fish fossil element which merits further study.
The specimen originating from the lower Cretaceous fossil bed of the Taouz oases in Morocco. The fossil layers in the Kem Kem formation are around 200 feet thick. The layers at the point where this fossil fish was unearthed are marly carbonate overlaying a carbonate escarpment. The ferruginous sandstones lie midway up this section. This area was previously known as the continental Intercalaire (Lavocat, 1954; Joly, 1962; Tabaste, 1963) and is now more well known as the Kem Kem beds (Sereno al.,1996).
References: Zoological Journal of the Linnean Society (1998), 123: 179-195. Article ID:zj980134, by Peter Forey Department of Palaeontology, NHM, London and Lance Grande, Department of Geology, Field Museum of National History, Chicago.