The El Mers Group is a

geological group In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into superg ...

in the

Middle Atlas The Middle Atlas (Amazigh: ⴰⵟⵍⴰⵙ ⴰⵏⴰⵎⵎⴰⵙ, ''Atlas Anammas'', Arabic: الأطلس المتوسط, ''al-Aṭlas al-Mutawassiṭ'') is a mountain range in Morocco. It is part of the Atlas mountain range, a mountainous region ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

. It is subdivided into 3 formations named the El Mers 1, 2 and 3 Formations respectively. It is a marine deposit primarily consisting of

marl Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part o ...

, with

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...

present in the upper part of unit 3. and is the lateral equivalent of the terrestrial Guettioua Sandstone. Dinosaur remains are among the fossils that have been recovered from the group, most notably those of indeterminate

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

s (=

Allosauridae Allosauridae is a family of medium to large bipedal, carnivorous allosauroid theropod dinosaurs from the Late Jurassic. Allosauridae is a fairly old taxonomic group, having been first named by the American paleontologist Othniel Charles Marsh in ...

indet. and =

Megalosauridae Megalosauridae is a monophyletic family of carnivorous theropod dinosaurs within the group Megalosauroidea. Appearing in the Middle Jurassic, megalosaurids were among the first major radiation of large theropod dinosaurs. They were a relatively ...

? indet.),J. Jenny, A. Le Marrec, and M. Monbaron. (1981). Les empreintes de pas de dinosauriens dans le Jurassique moyen du Haut Atlas central (Maroc): nouveaux gisements et precisions stratigraphiques. inosaur footprints in the Middle Jurassic of the central High Atlas (Morocco): new deposits and stratigraphic detailsGeobos. 14(3):427-431 the

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

''"Cetiosaurus" mogrebiensis'', the

stegosaur Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere, predominantly in what is now North America, Europe, ...

Adratiklit ''Adratiklit'' (meaning "mountain lizard") is an extinct genus of herbivorous stegosaurian dinosaur that lived on the supercontinent Gondwana during the Middle Jurassic period (168–164 million years ago). The genus contains a single species, '' ...

'', the

ankylosaur Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. ...

Spicomellus ''Spicomellus'' (meaning "collar of spikes") is an extinct genus of herbivorous ankylosaurian dinosaur that lived in the supercontinent Gondwana during the Middle Jurassic Period. The type and only known species is ''Spicomellus afer'', named ...

'', the inchnofossil ''

Selenichnites ''Selenichnites'' (‘moon track’) is a Cambrian to Jurassic trace fossil that has been found on every continent. It consists of crescent-shaped impressions interpreted as resting or burrowing traces of Xiphosura (extinct relatives of horsesho ...

'' and an indeterminate

teleosauroid Teleosauroidea is an extinct superfamily of thalattosuchian crocodyliforms living from the Early Jurassic to the Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier o ...

Machimosauridae Machimosauridae is an extinct family of teleosauroid thalattosuchian crocodyliforms. Text was copied from this source, which is available under Creative Commons Attribution 4.0 International License The family was first identified in 2016, wh ...

indet.).

References

{{reflist Geologic groups of Africa Geologic formations of Morocco Jurassic System of Africa Jurassic Morocco Bathonian Stage Callovian Stage Shale formations Evaporite deposits Ichnofossiliferous formations Paleontology in Morocco