Anoual Formation

Anoual Formation
Stratigraphic range: Early Bathonian
TypeGeological formation
Unit ofAnoual Syncline
Sub-unitsLower Member, Upper Member
UnderliesUnconformity with Ksar Metlili Formation
OverliesPholadomya Marls and Limestones Formation
Thickness~500 m (1,600 ft)
Lithology
PrimaryMudstone (Lower), limestone (Upper)
OtherSandstone, limestone, marl (Lower)
Location
Coordinates32°30′N 3°06′W / 32.5°N 3.1°W / 32.5; -3.1
Approximate paleocoordinates26°54′N 0°54′E / 26.9°N 0.9°E / 26.9; 0.9
RegionFiguig Province
CountryMorocco
ExtentHigh Atlas
Type section
Named forAnoual
Anoual Formation is located in Morocco
Anoual Formation
Anoual Formation (Morocco)

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

Genus Species Location Stratigraphic Position Material Notes Images
Burmirhynchia
  • B. gr. termierae-athiaensis
 Anoual Lower Member Isolated shells A brachiopod of the family Tetrarhynchiidae
Kallirhynchia
  • K. oranensis
 Anoual Lower Member Isolated shells A brachiopod of the family Tetrarhynchiidae
Kallirhynchia specimen

Crustacea

Genus Species Location Stratigraphic Position Material Notes Images
Asciocythere
  • A. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the family Schulerideidae.
Bythocypris
  • B. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the family Bythocyprididae
Asciocythere
  • A. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the family Schulerideidae.
Cypridea
  • C. cf. postelongata
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the family Cyprididae
Cypris
  • C. spp.
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the family Cyprididae
Darwinula
  • D. magna
  • D. cf. leguminella
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the family Darwinulidae
Fabanella
  • F. bathonica
  • F. sp.
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the order Podocopida
Fastigocythere
  • F. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the order Podocopida
Klieana
  • K. levis
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the order Cytherideidae
Kinkelinella
  • K. sp.
 Anoual Lower Member Isolated Valves A Freshwater/Brackish Ostracod of the family Protocytheridae
Mantelliana
  • M. sp.
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the family Cyprididae
Metacypris
  • M. sp.
 Anoual Upper Member Isolated Valves A Freshwater/Brackish Ostracod of the family Limnocytheridae
Paracypris
  • P. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the family Candonidae. Dominant marine taxon
Pneumatocythere
  • P.? juglandiformis
 Anoual Lower Member Isolated Valves A Marine Ostracod of the order Podocopida
Praeschuleridea
  • P. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the family Candonidae.
Procytheridea
  • P. sp.
 Anoual Lower Member Isolated Valves A Marine Ostracod of the order Podocopida
Scabriculocypris
  • S. sp.
 Anoual Upper Member Isolated Valves A Freshwater Ostracod of the family Cyprididae
Theriosynoecum
  • T. sp.
 Anoual Upper Member Isolated Valves A Freshwater/Brackish Ostracod of the family Limnocytheridae

Mollusca

Genus Species Location Stratigraphic Position Material Notes Images
Lymnaeidae indet. Indeterminate Guelb el Ahmar Upper Member Isolated shells Freshwater snails
Nerineidae indet. Indeterminate Anoual Lower Member Isolated shells Marine snails
Planorbidae indet. Indeterminate Guelb el Ahmar Upper Member Isolated shells Freshwater snails
Provalvata P. sp. Anoual Upper Member Isolated shells Freshwater snail of the family Provalvatidae
Valvatidae indet. Indeterminate Guelb el Ahmar Upper Member Isolated shells Freshwater 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.

Genus Species Location Stratigraphic Position Material Notes Images
Arganodus A. sp. Guelb el Ahmar Upper Member Isolated tooth plates Lungfish
Arganodus reconstruction
Lepidotes/Scheenstia L./S. sp. Guelb el Ahmar Upper Member Isolated teeth and scales Lepidotidae bony fish
Lepidotes reconstruction
cf. Ionoscopiformes indet. Indeterminate Guelb el Ahmar Upper Member Rhomboidal scales Tentatively assigned to Ophiopsidae
Mawsoniidae indet. Indeterminate Guelb el Ahmar Upper Member Skull bones including a parasphenoid Coelacanth
Osteoglossiformes indet. Indeterminate Guelb el Ahmar Upper Member Squamules (small scales) The oldest record of the group

Amphibians

Genus Species Location Stratigraphic Position Material Notes Images
Albanerpetontidae indet. Indeterminate Guelb el Ahmar Upper Member Incomplete premaxilla and incomplete frontal Likely represents a new taxon
Caudata? indet. Indeterminate Guelb el Ahmar Upper Member Fragment of a dentary
Lissamphibia? indet. Indeterminate Guelb el Ahmar Upper Member Fragment of a maxilla

Turtles

Genus Species Location Stratigraphic Position Material Notes Images
Testudinata indet. "Morphotype 1" Guelb el Ahmar Upper Member Fifty plate fragments Similar to Solemydidae and Pleurosternidae turtles
"Morphotype 2" Guelb el Ahmar Upper Member Single neural plate Plate slightly longer than wide
"Morphotype 3" Guelb el Ahmar Upper Member Multiple plates By far the most abundant, maybe a larger taxon with smooth plates
"Morphotype 4" Guelb el Ahmar Upper Member Two costal plates Similar to Araripemys and some Trionychidae

Lepidosaurs

Genus Species Location Stratigraphic Position Material Notes Images
Parviraptor cf. P. sp. Guelb el Ahmar Upper Member Four vertebral centra Squamatan, previously identified as a stem-snake
Rhynchocephalia indet. Indeterminate Guelb el Ahmar Upper Member One 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. Indeterminate Guelb el Ahmar Upper Member A fragment of bone bearing teeth; potentially a fragment of bone bearing one complete tooth Squamatan
Squamata indet. Indeterminate Guelb el Ahmar Upper Member Incomplete maxilla, incomplete dorsal vertebra, one proximal part of femur

Choristoderes

Genus Species Location Stratigraphic Position Material Notes Images
Choristodera indet. Indeterminate Guelb el Ahmar Upper Member Fragmentary dentary, centrum of an anterior caudal vertebra, possibly centrum of a dorsal vertebra Similar to Cteniogenys

Dinosaurs

Genus Species Location Stratigraphic Position Material Notes Images
Ornithischia indet. Indeterminate Guelb el Ahmar Upper Member Tooth Similar to Alocodon
Illustration of a fossil of Alocodon
cf. Stegosauria indet. Indeterminate Guelb el Ahmar Upper Member Poorly preserved tooth
Theropoda indet. Indeterminate Guelb el Ahmar Upper Member Several teeth

Pterosaurs

Genus Species Location Stratigraphic Position Material Notes Images
Pterosauria indet. Indeterminate Guelb el Ahmar Upper Member Teeth Similar to wukongopterids
Rhamphorhynchidae indet. Indeterminate Guelb el Ahmar Upper Member Teeth

Crocodyliformes

Genus Species Location Stratigraphic Position Material Notes Images
Atoposauridae indet. Indeterminate Guelb el Ahmar Upper Member Teeth
Ctenosuchus C. tenuidens Anoual–Talsint Lower Member? Two specimens, both including a partial skull and osteoderms. One also preserves a partial postcranial skeleton. A teleosaurid thalattosuchian Holotype specimen
Teleosauridae indet. Indeterminate Guelb el Ahmar Upper Member Teeth
Thalattosuchia indet. Indeterminate Guelb el Ahmar Upper Member Teeth, various skeletal elements probably belonging to a single individual
Theriosuchus cf. T. sp. Guelb el Ahmar Upper Member Teeth An atoposaurid

Mammals

Genus Species Location Stratigraphic Position Material Notes Images
Amphitheriidae indet. Indeterminate Guelb el Ahmar Upper Member Fragment of juvenile right dentary; fragment of an edentulous right dentary, probably middle-posterior part. If true is the 1st Gondwanic member of the family
cf. Dryolestida/Donodontidae indet. Indeterminate Guelb el Ahmar Upper Member Fragment of a tooth bearing one cusp and one root Similar to Donodon

Charophyta

Genus Species Location Stratigraphic Position Material Notes Images
Aclistochara A. africana Guelb el Ahmar Upper Member Gyrogonites A Characean algae of the family Characeae
Porochara P. hians Anoual Upper Member Oogonia A characean algae of the family Porocharaceae

Palynology

Genus Species Location Stratigraphic Position Material Notes Images
Alisporites
  • A. spp.
 Guelb el Ahmar Upper Member Pollen Affinities with the families Peltaspermaceae or Corystospermaceae
Araucariacites
  • A. australis
 Guelb el Ahmar Upper Member Pollen Affinities with Araucariaceae inside Coniferae.
Example of extant Araucaria cones
Callialasporites
  • C. spp.
 Guelb el Ahmar Upper Member Pollen Affinities with Araucariaceae inside Coniferae.
Classopollis
  • C. spp.
 Guelb el Ahmar Upper Member Pollen Affinities with Cheirolepidiaceae inside Coniferae.
Cyathidites
  • C. sp.
 Guelb el Ahmar Upper Member Spores Affinities with the family Cyatheaceae inside Cyatheales. Arboreal Fern Spores
Modern Cyathea, Cyathidites come probably from similar genera
Cycadopites
  • C. spp.
 Guelb el Ahmar Upper Member Pollen Affinities with the Cycadopsida inside Cycadales. Pollen related with modern Cycas
Encephalartos, Cycadopites come probably from similar genera
Inaperturopollenites
  • I. spp.
 Guelb el Ahmar Upper Member Pollen Affinities with the Pinidae inside Coniferae.
Extant Pinus Cone. Inaperturopollenites is similar to the pollen found on this genus
Ischyosporites
  • I. cf. variegatus
  • I. sp
 Guelb el Ahmar Upper Member Spores Affinities with Pteridopsida, likely derived from a member of Anemiaceae
Extant Anemia specimens; Ischyosporites probably comes from similar genera
Leptolepidites
  • L. spp.
 Guelb el Ahmar Upper Member Spores Affinities with the family Dennstaedtiaceae in the Polypodiales. Forest fern spores.
Extant Dennstaedtia specimens; Leptolepidites probably comes from similar genera
Pityosporites
  • P. sp.
 Guelb el Ahmar Upper Member Pollen Affinities with the Pinidae inside Coniferae.

Fossil Wood

Genus Species Location Stratigraphic Position Material Notes Images
Agathoxylon
  • A. aff. sahariense
  • Guelb el Ahmar
  • Oued Metlili
 Upper Member Fossil Wood Conifer fossil wood of the family Araucariaceae
Metapodocarpoxylon
  • M. libanoticum
  • Guelb el Ahmar
  • Oued Metlili
 Upper Member Fossil Wood Conifer fossil wood of the family Podocarpaceae
Protopodocarpoxylon
  • P. subrochii
  • P. teixeirae
  • Guelb el Ahmar
  • Oued Metlili
 Upper Member Fossil Wood Conifer fossil wood of the family Hirmeriellaceae
Phyllocladoxylon
  • P. atlasicum
  • Guelb el Ahmar
  • Oued Metlili
 Upper Member Fossil Wood Conifer fossil wood of the family Podocarpaceae

See also

References

  1. 1 2 3 4 5 6 7 8 9 Haddoumi, Hamid; Charrière, André; Andreu, Bernard; Mojon, Pierre-Olivier (2008). "Les dépôts continentaux du Jurassique moyen au Crétacé inférieur dans le Haut Atlas oriental (Maroc) : paléoenvironnements successifs et signification paléogéographique". Carnets de Géologie / Notebooks on Geology. CG2008 (A06): 1–29.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Haddoumi, Hamid; Allain, Ronan; Meslouh, Said; Metais, Grégoire; Monbaron, Michel; Pons, Denise; Rage, Jean-Claude; Vullo, Romain; Zouhri, Samir (January 2016). "Guelb el Ahmar (Bathonian, Anoual Syncline, eastern Morocco): First continental flora and fauna including mammals from the Middle Jurassic of Africa" (PDF). Gondwana Research. 29 (1): 290–319. Bibcode:2016GondR..29..290H. doi:10.1016/j.gr.2014.12.004. ISSN 1342-937X.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Haddoumi, Hamid; Aiméras, Yves; Bodergat, Anne-Marie; Charrière, André; Mangold, Charles; Benshili, Khadija (1998-07-01). "Âges et environnements des Couches rouges d'Anoual (Jurassique moyen et Crétacé inférieur, Haut-Atlas oriental, Maroc)". Comptes Rendus de l'Académie des Sciences - Series IIA - Earth and Planetary Science. 327 (2): 127–133. doi:10.1016/S1251-8050(98)80043-8. ISSN 1251-8050.
  4. ↑ Imran, Hamzah; Martill, David M.; Smith, Roy E.; Zouhri, Samir; Gunn, James; Ibrahim, Nizar (2026-10-08). "A new teleosauroid (Crocodylomorpha, Thalattosuchia) with a unique dentition from the Middle Jurassic of eastern Morocco". Journal of Vertebrate Paleontology e2728670. doi:10.1080/02724634.2026.2728670.
  5. ↑ MOJON, Pierre-Olivier; HADDOUMI, Hamid; CHARRIÈRE, André (2009). "Nouvelles données sur les Charophytes et Ostracodes du Jurassique moyen-supérieur - Crétacé inférieur de l'Atlas marocain". Carnets de géologie (Notebooks on geology) (Mémoires). doi:10.4267/2042/29781. ISSN 1634-0744.