The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous.
Dinosaur remains are among the fossils that have been recovered from the group.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 604-605. . Recent fossil evidence in the form of isolated large abelisaurid bones and comparisons with other similarly aged deposits elsewhere in Africa indicates that the fauna of the Kem Kem Group (specifically in regard to the numerous predatory theropod dinosaurs) may have been mixed together due to the harsh and changing geology of the region, when in reality they would likely have preferred separate habitats and likely would have been separated by millions of years.
Stratigraphy and paleoenvironment Although preserving a freshwater habitat located near a river delta (with some estuarine influence that increased over time as the sea level rose), the Kem Kem deposits were quickly submerged by the sea during the Cenomanian-Turonian boundary event, and are thus overlaid by the marine deposits of the younger latest Cenomanian and early-mid Turonian-aged Akrabou Formation, which was formerly also considered a member of the Kem Kem Group, but has been differentiated from it in more recent studies due to their differing paleoenvironments.
Its strata are subdivided into two geological formations, with the lower Ifezouane Formation and the upper Aoufous Formation used for the strata on the eastern side of the Atlas Mountains (Tinghir), with the Gara Sbaa Formation and Douira Formation used in the southern Tafilalt region. It is exposed on an escarpment along the Algeria–Morocco border. According to Ibrahim, the Lower Kem Kem consists of the Ifezouane & Gara Sbaa Formations, while the Upper Kem Kem is consisted of The Douira & Aufous Formations.
The unit unconformably overlies Paleozoic marine units of Cambrian, Silurian and Devonian ages and is itself capped by limestone platform rock of Cenomanian-Turonian age. It primarily consists of freshwater and estuarine deltaic deposits. The lower Gara Sbaa Formation primarily consists of fine and medium grained sandstone, while the Douira Formation consists of fining-upward, coarse-to-fine grained sandstones intercalated with siltstones, variegated mudstones, and occasional thin gypsiferous evaporites.
The Kem Kem is interpreted as being deposited in a tropical semi-arid climate, with brief monsoon rains. It is believed to Span the Lower to Middle Cenomanian, a span of roughly 100-95 mya.
Vertebrate paleofauna Cartilaginous fish Cartilaginous fish Genus Species Location Stratigraphic position Material Notes Images Acrodontidae indet. Indeterminate Members of Hybodontoidea Bahariyodon B. bartheli A member of Hybodontoidea Cenocarcharias C. tenuiplicatus One tooth A member of the family Cretoxyrhinidae Distobatus D. nutiae A member of Hybodontoidea Haimirichia H. amonensis One tooth A mackerel sharkMarckgrafiaM. lybica 13 teeth A member of Batoidea Onchopristis O. numida Various isolated, and some articulated remains A rajiform sawskate Peyeria P. libyca Three teeth A sawskate. Might be a junior synonym of Onchopristis numida. Tribodus T. sp. A member of Hybodontoidea
Ray-finned fish Ray-finned fish Genus Species Location Stratigraphic position Material Notes Images Adrianaichthys A. pankowskii Isolated scales and two skulls A member of Lepisosteiformes. Originally described as a species of Lepidotes, but subsequently transferred to a separate genus. Afrocascudo A. saharaensis A neopterygiian fish, either an ancient loricariid catfish or a juvenile obaichthyid lepisosteiform. Agassizilia A. erfoudina Possibly a member of the family Pycnodontidae. Agoultichthys A. chattertoni A long-bodied member of Actinopterygii of uncertain phylogenetic placement. Might be a member of the family Macrosemiidae or Ophiopsiellidae. Aidachar A. pankowskii Ifezouane Formation Isolated braincase and teeth A member of Ichthyodectiformes Bartschichthys B. sp. Isolated pinnulae (spines that support each dorsal finlet) A cladistian Bawitius cf. B. sp. Isolated scales and jaw fragments A cladistian Calamopleurus C. africanus A partial skull A member of Amiiformes Concavotectum C. moroccensis Tizi Moumrad, Chaaft, and Douira Isolated braincases, post cranial remains A member of Tselfatiiformes Dentilepisosteus D. kemkemensis A member of Lepisosteiformes Diplomystus D. sp. A deep-bodied teleost belonging to the group Clupeomorpha Diplospondichthys D. moreaui A member of Actinopterygii of uncertain phylogenetic placement, possibly a teleost Erfoudichthys E. rosae Isolated skull A small-bodied teleost of unknown affinity Neoproscinetes N. africanus A member of the family Pycnodontidae Obaichthys O. africanus Ifezouane Formation Isolated scales A member of Lepisosteiformes Oniichthys O. falipoui Near complete skeleton including skull A member of Lepisosteiformes Palaeonotopterus P. greenwoodi A member of Osteoglossomorpha Serenoichthys S. kemkemensis Several articulated skeletons A small cladistian Spinocaudichthys S. oumtkoutensis An elongate freshwater acanthomorph Stromerichthys S. aethiopicus Sudania S. sp. An isolated pinnula A cladistian
Lobe-finned fish Lobe-finned fish Genus Species Location Material Notes Images Arganodus A. tiguidiensis A lungfish Axelrodichthys A.? lavocati A mawsoniid coelacanth; this species was previously assigned to Mawsonia, and its generic assignment is still not certain Neoceratodus N. africanus Isolated tooth plates A lungfish
Amphibians Amphibians Genus Species Location Stratigraphic position Material Notes Images Anura indet. Indeterminate Douira Formation Incomplete left ilium Cretadhefdaa C. taouzensis Douira Formation Posterior portion of the skull, incomplete squamosal, incomplete maxilla, three incomplete presacral vertebrae, one incomplete sacral vertebra A neobatrachian frog with possible hyloid affinities. cf. Kababisha Indeterminate A salamander belonging to the family Sirenidae ?Neobatrachia indet. Indeterminate Douira Formation Incomplete humerus A frog, possibly a member of Ranoidea. Oumtkoutia O. anae A frog belonging to the family Pipidae
Lizards and snakes
Lizards and snakes reported from the Continental Red Beds Genus Species Location Stratigraphic position Material Notes ImagesBicuspidonB. hogreliA polyglyphanodontid lizard.JeddaherdanJ. aleadontaPartial mandible with teeth.An iguanian belonging to the group Acrodonta, possibly a relative of the uromastycine agamids. Argued by Vullo et al. (2022) to actually come from Quaternary beds, and to be based on a fossil material of a member of the genus Uromastyx.LapparentophisL. rageiTwo isolated trunk vertebraeAn early snake.Madtsoiidae indet.IndeterminateVertebraeAn early snake.?Nigerophiidae indet.IndeterminateDorsal vertebraeAn early snake.NorisophisN. begaaOne posterior and two mid-trunk vertebraeA stem-snake.IndeterminateA mid-trunk vertebraSimoliophiscf. S. libycusVertebraeAn early snake.
Plesiosaurs Plesiosaurs Genus Species Location Stratigraphic position Material Notes Images Leptocleididae cf. Leptocleidus indeterminate Isolated teeth, a humerus and vertebrae
Turtles Turtles reported from the Continental Red Beds Genus Species Location Stratigraphic position Material Notes ImagesDirqadimD. schaefferi A EuraxemydidGalianemys G. emringeri A CearachelyinG. whiteiSkull materialHamadachelys H. escuillieiSkull and mandibleA basal Podocnemidoid
Crocodylomorphs
Crocodylomorphs reported from the Continental Red Beds Genus Species Location Stratigraphic position Material Notes ImagesAegisuchusA. witmeri"Partial braincase of a large individual with skull roof, temporal, and occipital regions."An aegyptosuchid that may be a synonym of Laganosuchus.AntaeusuchusA. taouzensisNear Jebel Beg'aa, TaouzPaired mandibles and a partial right mandibleA peirosaurid.AraripesuchusA. rattoidesDouira Formation ElosuchusE. cherifiensis Gara Sbaa Formation Douira FormationA pholidosaurid. The material may represent two different species.HamadasuchusH. rebouli Gara Sbaa Formation Douira FormationA peirosaurid.KemkemiaK. auditoreiErrachidia Province, MoroccoKnown from an isolated caudal vertebra.Initially thought to be a neotheropod,Cau, Andrea; Maganuco, Simone (2009). "A new theropod dinosaur, represented by a single unusual caudal vertebra from the Kem Kem Beds (Cretaceous) of Morocco". Atti Soc. it. Sci. nat. Museo civ. Stor. nat. Milano 150 (II): 239–257. but subsequently discovered to be an indeterminate crocodyliform.Lio, G., Agnolin, F., Cau, A. and Maganuco, S. (2012). "Crocodyliform affinities for Kemkemia auditorei Cau and Maganuco, 2009, from the Late Cretaceous of Morocco." Atti della Società Italiana di Scienze Naturali e del Museo di Storia Naturale di Milano, 153 (I), s. 119–126. LaganosuchusL. maghrebensisA stomatosuchid.LavocatchampsaL. sigogneaurusselaeAnterior portion of a rostrum with mandible, with an almost complete dentition A candidodontid notosuchian.Notosuchia indet.IndeterminateDouira FormationTeethIndeterminate notosuchians. Represent by distinct multicuspid teeth,similar to Adamantinasuchus & Yacarerani. Suggestive of a herbivorous diet.cf. SarcosuchusIndeterminateTeeth and OsteodermsPossible remains of Sarcosuchus. Additional Cenomanian occurrences known from Algeria.
Dinosaurs Indeterminate lithostrotian remains once misattributed to the Titanosauridae are present in the province of Ksar-es-Souk, Morocco.
Ornithischians Ornithischians reported from the Continental Red Beds Genus Species Location Stratigraphic position Material Notes ImagesThyreophoraIndeterminateDouira FormationAn isolated tooth.An indeterminate thyreophoran. Possibly an ankylosaur.OrnithopodaIndeterminateDouira FormationA large, clover-shaped, three-toed footprint. A smaller print is known as well.Comparable in size and shape to tracks typically attributed to Iguanodon. Smaller possible ornithopod track is known as well. Sauropods Sauropods reported from the Continental Red Beds Genus Species Location Stratigraphic position Material Notes ImagesRebbachisaurusR. garasbaeKsar-es-Souk province, Morocco.Gara Sbaa FormationA rebbachisaurid. SomphospondyliIndeterminateAnterior dorsal vertebra, partial right ischiumThe vertebra might belong to a basal titanosaurian, possibly distinct from Aegyptosaurus and Paralititan. The ischium is not identifiable beyond Somphospondyli; it preserves numerous grooves and pits which might be feeding traces left by a very large non-avian theropod.TitanosauriaIndeterminate Ifezouane Formation Douira FormationIsolated teeth, caudal vertebrae, a partial humerus, a tarsal bone and proximal partial ulna.Fossil material of one or more titanosaurian sauropods. Some fossils are indicative of large body size comparable to Paralititan stromeri. The largest specimens hail from the Douira Formation. An ulna from Doira has a width of 51 cm.Rebbachisauridae Indet.Indeterminate Douira FormationTeethTeeth referred to an indeterminate rebbachisaurid.
Theropods