The Anoual Formation is a geological formation in the High Atlas of Morocco. It is early Bathonian in age. It consists of two members. The lower member is several hundred metres thick, and consists largely of mudstone with lens beds of cross bedded sandstone, with thin intercalations of limestone that was deposited in a freshwater continental setting, likely lacustrine or palustrine, with small marine influences. The upper member is several tens of metres thick and consists of limestone deposited in a shallow marine setting. The formation is fossiliferous, with several of the limestone intercalations yielding a diverse fauna, including amphibians, reptiles, dinosaurs and mammals.
Paleobiota
Brachiopoda GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesBurmirhynchia B. gr. termierae-athiaensisAnoual Lower MemberIsolated shellsA brachiopod of the family Tetrarhynchiidae Kallirhynchia K. oranensisAnoualLower MemberIsolated shellsA brachiopod of the family Tetrarhynchiidae
Crustacea GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAsciocythere A. sp.Anoual Lower MemberIsolated ValvesA Marine Ostracod of the family Schulerideidae. Bythocypris B. sp.Anoual Lower MemberIsolated ValvesA Marine Ostracod of the family BythocyprididaeAsciocythere A. sp.Anoual Lower MemberIsolated ValvesA Marine Ostracod of the family Schulerideidae. Cypridea C. cf. postelongataAnoual Upper MemberIsolated ValvesA Freshwater Ostracod of the family CyprididaeCypris C. spp.Anoual Upper MemberIsolated ValvesA Freshwater Ostracod of the family CyprididaeDarwinula D. magna D. cf. leguminellaAnoual Upper MemberIsolated ValvesA Freshwater Ostracod of the family DarwinulidaeFabanella F. bathonica F. sp.Anoual Upper MemberIsolated ValvesA Freshwater Ostracod of the order PodocopidaFastigocythere F. sp.Anoual Lower MemberIsolated ValvesA Marine Ostracod of the order PodocopidaKlieana K. levisAnoualUpper MemberIsolated ValvesA Freshwater Ostracod of the order CytherideidaeKinkelinella K. sp.AnoualLower MemberIsolated ValvesA Freshwater/Brackish Ostracod of the family ProtocytheridaeMantelliana M. sp.AnoualUpper MemberIsolated ValvesA Freshwater Ostracod of the family CyprididaeMetacypris M. sp.Anoual Upper MemberIsolated ValvesA Freshwater/Brackish Ostracod of the family LimnocytheridaeParacypris P. sp.Anoual Lower MemberIsolated ValvesA Marine Ostracod of the family Candonidae. Dominant marine taxonPneumatocythere P.? juglandiformisAnoual Lower MemberIsolated ValvesA Marine Ostracod of the order PodocopidaPraeschuleridea P. sp.Anoual Lower MemberIsolated ValvesA Marine Ostracod of the family Candonidae. Procytheridea P. sp.AnoualLower MemberIsolated ValvesA Marine Ostracod of the order PodocopidaScabriculocypris S. sp.AnoualUpper MemberIsolated ValvesA Freshwater Ostracod of the family CyprididaeTheriosynoecum T. sp.AnoualUpper MemberIsolated ValvesA Freshwater/Brackish Ostracod of the family Limnocytheridae
Mollusca GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesLymnaeidae indet.IndeterminateGuelb el AhmarUpper MemberIsolated shellsFreshwater snailsNerineidae indet.IndeterminateAnoualLower MemberIsolated shellsMarine snailsPlanorbidae indet.IndeterminateGuelb el AhmarUpper MemberIsolated shellsFreshwater snailsProvalvataP. sp.AnoualUpper MemberIsolated shellsFreshwater snail of the family ProvalvatidaeValvatidae indet.IndeterminateGuelb el AhmarUpper MemberIsolated shellsFreshwater snails
Fish Abundant osteichthyan ichthyoliths are known. An isolated spine displaying characters seen in extant cypriniform or siluriform fishes has been recovered, alternatively can belong to a member of Myriacanthidae. GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesArganodus A. sp.Guelb el AhmarUpper MemberIsolated tooth platesLungfishLepidotes/Scheenstia L./S. sp.Guelb el AhmarUpper MemberIsolated teeth and scalesLepidotidae bony fishcf.Ionoscopiformes indet. IndeterminateGuelb el AhmarUpper MemberRhomboidal scalesTentatively assigned to OphiopsidaeMawsoniidae indet. IndeterminateGuelb el AhmarUpper MemberSkull bones including a parasphenoidCoelacanthOsteoglossiformes indet. IndeterminateGuelb el AhmarUpper MemberSquamules (small scales)The oldest record of the group
Amphibians GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAlbanerpetontidae indet. IndeterminateGuelb el AhmarUpper MemberIncomplete premaxilla and incomplete frontalLikely represents a new taxonCaudata? indet.IndeterminateGuelb el AhmarUpper MemberFragment of a dentaryLissamphibia? indet.IndeterminateGuelb el AhmarUpper MemberFragment of a maxilla
Turtles GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesTestudinata indet."Morphotype 1"Guelb el AhmarUpper MemberFifty plate fragmentsSimilar to Solemydidae and Pleurosternidae turtles"Morphotype 2"Guelb el AhmarUpper MemberSingle neural platePlate slightly longer than wide"Morphotype 3"Guelb el AhmarUpper MemberMultiple platesBy far the most abundant, maybe a larger taxon with smooth plates"Morphotype 4"Guelb el AhmarUpper MemberTwo costal platesSimilar to Araripemys and some Trionychidae
Lepidosaurs GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesParviraptor Cf.P.sp.Guelb el AhmarUpper MemberFour vertebral centraSquamatan, previously identified as a stem-snakeRhynchocephalia indet.IndeterminateGuelb el AhmarUpper MemberOne fragment of dentary bearing two incomplete teeth; one fragment of maxilla bearing the bases of two teeth.Similar to the co-regional but younger genus Tingitana, but also to Clevosaurus.Scincomorpha indet.IndeterminateGuelb el AhmarUpper MemberA fragment of bone bearing teeth; potentially a fragment of bone bearing one complete toothSquamatanSquamata indet.IndeterminateGuelb el AhmarUpper MemberIncomplete maxilla, incomplete dorsal vertebra, one proximal part of femur
Choristoderes GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesChoristodera indet.IndeterminateGuelb el AhmarUpper MemberFragmentary dentary, centrum of an anterior caudal vertebra, possibly centrum of a dorsal vertebraSimilar to Cteniogenys
Dinosaurs GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesOrnithischia indet.IndeterminateGuelb el AhmarUpper MemberToothSimilar to Alocodoncf.Stegosauria indet.IndeterminateGuelb el AhmarUpper MemberPoorly preserved toothTheropoda indet. IndeterminateGuelb el AhmarUpper MemberSeveral teeth
Pterosaurs GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesPterosauria indet.IndeterminateGuelb el AhmarUpper MemberTeethSimilar to wukongopteridsRhamphorhynchidae indet. IndeterminateGuelb el AhmarUpper MemberTeeth
Crocodyliformes GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAtoposauridae indet.IndeterminateGuelb el AhmarUpper MemberTeethTeleosauridae indet.IndeterminateGuelb el AhmarUpper MemberTeethThalattosuchia indet.IndeterminateGuelb el AhmarUpper MemberTeeth, various skeletal elements probably belonging to a single individualTheriosuchusCf.T. sp.Guelb el AhmarUpper MemberTeethAn Atoposaurid
Mammals GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAmphitheriidae indet.IndeterminateGuelb el AhmarUpper MemberFragment of juvenile right dentary; fragment of an edentulous right dentary, probably middle-posterior part.If true is the 1st Gondwanic member of the familyCf.Dryolestida/Donodontidae indet.IndeterminateGuelb el AhmarUpper MemberFragment of a tooth bearing one cusp and one rootSimilar to Donodon
Charophyta GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAclistocharaA. africanaGuelb el AhmarUpper MemberGyrogonitesA Characean algae of the family CharaceaePorocharaP. hiansAnoualUpper MemberOogoniaA characean algae of the family Porocharaceae
Palynology GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAlisporites A. spp.Guelb el AhmarUpper MemberPollenAffinities with the families Peltaspermaceae or CorystospermaceaeAraucariacites A. australisGuelb el AhmarUpper MemberPollenAffinities with Araucariaceae inside Coniferae. Callialasporites C. spp.Guelb el AhmarUpper MemberPollenAffinities with Araucariaceae inside Coniferae.Classopollis C. spp.Guelb el AhmarUpper MemberPollenAffinities with Cheirolepidiaceae inside Coniferae.Cyathidites C. sp.Guelb el AhmarUpper MemberSporesAffinities with the family Cyatheaceae inside Cyatheales. Arboreal Fern SporesCycadopites C. spp.Guelb el AhmarUpper MemberPollenAffinities with the Cycadopsida inside Cycadales. Pollen related with modern CycasInaperturopollenites I. spp.Guelb el AhmarUpper MemberPollenAffinities with the Pinidae inside Coniferae. Ischyosporites I. cf. variegatus I. spGuelb el AhmarUpper MemberSporesAffinities with Pteridopsida, likely derived from a member of AnemiaceaeLeptolepidites L. spp.Guelb el Ahmar Upper MemberSporesAffinities with the family Dennstaedtiaceae in the Polypodiales. Forest fern spores.Pityosporites P. sp.Guelb el AhmarUpper MemberPollenAffinities with the Pinidae inside Coniferae.
Fossil Wood GenusSpeciesLocationStratigraphic PositionMaterialNotesImagesAgathoxylon A. aff. sahariense Guelb el Ahmar Oued MetliliUpper MemberFossil WoodConifer fossil wood of the family AraucariaceaeMetapodocarpoxylon M. libanoticum Guelb el Ahmar Oued MetliliUpper MemberFossil WoodConifer fossil wood of the family PodocarpaceaeProtopodocarpoxylon P. subrochii P. teixeirae Guelb el Ahmar Oued MetliliUpper MemberFossil WoodConifer fossil wood of the family HirmeriellaceaePhyllocladoxylon P. atlasicum Guelb el Ahmar Oued MetliliUpper MemberFossil WoodConifer fossil wood of the family Podocarpaceae
See also
Ksar Metlili Formation, from the Same area Guettioua Formation, coeval from the Azilal Region El Mers Group, coeval from the Skoura syncline Tafraout Group, older, from the Central High Atlas Azilal Formation, older, from the Central High Atlas
References