Sahel Alma (fossil site)

Sahel Alma or Sahel Aalma is a Late Cretaceous paleontological site and Konservat-Lagerstätte in Keserwan-Jbeil, Lebanon. Located near the town of the same name, it documents well-preserved deepwater marine fossils dating to the late Santonian stage of the Cretaceous. It is often associated with the slightly older, similarly famous Sannine Formation sites (Haqel, Hadjula, and Nammoura), with these four sites being together referred to as the "Fish Beds" of Lebanon.[1]

Sahel Alma
Stratigraphic range: Late Santonian
~85–84 Ma
TypeLagerstätte
Unit ofChekka Formation
Lithology
PrimaryChalk, limestone
Location
Coordinates34°00′N 35°42′E / 34.0°N 35.7°E / 34.0; 35.7
Approximate paleocoordinates12°54′N 30°24′E / 12.9°N 30.4°E / 12.9; 30.4
RegionKeserwan-Jbeil Governorate
Country Lebanon
Type section
Named forSahel Alma
Sahel Alma (fossil site) is located in Lebanon
Sahel Alma (fossil site)
Sahel Alma (fossil site) (Lebanon)

It is one of the few fossiliferous units of the Chekka Formation, a wider geological formation in Lebanon deposited from the Late Cretaceous to the early Paleogene.[2]

Description

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Much like the fossil sites of the older Sannine Formation, Sahel Alma contains exquisitely preserved marine fossils from the Tethys Ocean, deposited off the northern coast of the Afro-Arabian continent. However, unlike the Sannine Formation sites, which were deposited in relatively shallow waters near the shore on the inner continental shelf, Sahel Alma was deposited in a deepwater habitat off the continental slope, at depths estimated to be greater than 150 metres (490 ft), likely at the transition between the sublittoral and bathyal zones in dysphotic or aphotic conditions. This has caused it to preserve a distinct fauna from the Sannine Formation, with a significant number of deepwater arthropods and chondrichthyans.[1][3]

As with the sites of the Sannine Formation, the fossils of Sahel Alma are very well-preserved, and include the soft body parts of cartilaginous fish and cephalopods. Palaeoctopus, the first fossil octopus discovered with preserved soft tissues, was discovered from Sahel Alma.[1]

History

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The Sahel Alma monastery, built with bricks from the site

Sahel Alma is one of the oldest-known fossil sites in Lebanon, second only to the Haqel site of the Sannine Formation. It has been known of since the Seventh Crusade in the 13th century, when bricks quarried out of it were used to build the eponymous Maronite monastery at Sahel Alma. A fossil fish presented to King Louis IX around this time may have been from the site. The site was also likely documented by C. F. Volney during the early 1780s. British adventurer Lady Hester Stanhope settled near Sahel Alma in the early 19th century, and helped to collect and circulate fossils from the site and Haqel. Paul-Émile Botta was also another prolific early researcher of the site.[4]

The site is no longer accessible for scientific research as buildings were constructed over it, due to the purchase of the site by a private company, which restored the Sahel Alma monastery as a hotel.[1][5]

Paleobiota

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Vertebrates

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Cartilaginous fish

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Chondrichthyans reported from Sahel Alma[6][7]
Genus Species Notes Images
Acanthoscyllium A. sahelalmae A bamboo shark.
Almascyllium A. cheikheliasi A bamboo shark.
Anomotodon A. plicatus A goblin shark.  
Britobatos B. primarmata A potential relative of the thornback rays.[8]
Centrophoroides C. latidens A dogfish shark.
Centrosqualus C. primaevus A dogfish shark.
Cretascymnus C. adonis A sleeper shark.
Harriotta H. lehmani A long-nosed chimaera.  
Hexanchus H. gracilis A sixgill shark.  
Paratriakis P. curtirostris A houndshark.  
Propristiophorus P. tumidens A sawshark.  
Pteroscyllium P. dubertreti A catshark.
P. signeuxi
'Raja' 'R.' davisi A ray, either a guitarfish or a skate.[9][10]
"Rhinobatos" (gen. nov. 2) 'R.' tenuirostris A potential relative of the wedgefishes. Likely its own genus.[11]
"Rhinobatos" (gen. nov. 4) 'R.' intermedius A guitarfish-like ray. Likely its own genus, and its status as a guitarfish is disputed.[11]
'R.' latus
Scapanorhynchus S. lewisii A goblin shark.  
Sclerorhynchus S. atavus A sawskate.  
Scyliorhinus S. elongatus A catshark.  

Ray-finned fishes

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Actinopterygians reported from Sahel Alma[12][13][14]
Genus Species Notes Images
Acrogaster A. daviesi A trachichthyiform.
A. heckeli
Alloberyx A. syriacus A holocentriform.  
A. robustus
Benthesikyme B. gracilis A dercetid aulopiform.[15]  
Charitosomus C. lineolatus A gonorynchid.
C. major
Cheirothrix C. lewisii A flying fish-like eurypterygian, possibly an aulopiform.
C. libanicus  
Ctenocephalichthys C. brevispinus A holocentriform.
C. lorteti
Davichthys D. dubius An elopid.  
Dercetis D. triqueter A dercetid aulopiform.[15]  
Dinopteryx D. spinosus A dinopterygid beardfish.
Enchelurus E. syriacus An elopomorph sister to eels and notacanthiforms.[16]
Enchodus E. major An enchodontid aulopiform.  
E. longidens
Gnathoberyx G. stigmosus A trachichthyiform.
Histiothrissa H. crassapinna A clupeiform.  
Hoplopteryx H. spinulosus A trachichthyiform.  
H. syriacus
Ichthyotringa I. ferox An ichthyotringid aulopiform.  
I. furcata
I. damoni  
Istieus I. lebanonensis A bonefish.  
Omosoma O. intermedium A polymixiid beardfish.  
O. pulchellum
O. sahelalmae
Opistopteryx O. curtus A presumed elopiform.
O. gracilis
Osmeroides O. attenuatus A stem-bonefish.[17]
O. gracilis
O. sardinioides  
Pantopholis P. dorsalis An enchodontid aulopiform.
Parospinus P. cupulus A holocentriform.
Pronotacanthus P. sahelalmae A protostomiid fish (previously considered a spiny eel)[18]
Pycnosterinx P. discoides A polymixiid beardfish.  
P. dubius
P. gracilis
P. russeggeri
Sardinioides (=Leptosomus) S. macrurus A sardinioidid myctophiform.
S. megapterus  
S. pusillus
Spaniodon S. elongatus A euteleost, possibly an osmeriform.[19][17]  
S. latus  
Thrissopteroides T. tenuiceps An indeterminate teleost, possibly related to Spaniodon.
Urenchelys U. avus An eel.

Invertebrates

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Arthropods

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Arthropods reported from Sahel Alma[20]
Genus Species Notes Images
Carpopenaeus C. garassinoi A carpopenaeid prawn.[21]  
Cirolana C. cottreaui A cirolanid isopod.[22]  
C. garassinoi
Cretasergestes C. sahelalmaensis A sergestid prawn.
Hamaticaris H. damesi A protozoeid thylacocephalan.[23]
Keelicaris K. deborae A protozoeid thylacocephalan.[23]
Loriculina L. noetlingi A stramentid barnacle.[24]
Palaeobenthesicymus P. libanensis A benthesicymid shrimp.[3]  
Palaeobenthonectes P. arambourgi A benthesicymid shrimp.[25]
Palaeognathophausia P. libanotica A gnathophausiid crustacean.
Protozoea P. hilgendorfi A protozoeid thylacocephalan.[23]  
Pseuderichtus P. cretaceus A protozoeid thylacocephalan.[23]
Pseudodrobna P. natator A penaeid prawn.[25]
Pseudoranina P. guinotae A raninid crab.
Thylacocephalus T. cymolopos A microcaridid thylacocephalan.[23]

Molluscs

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Molluscs reported from Sahel Alma
Genus Species Notes Images
?Boreopeltis B. smithi A plesioteuthid coleoid, known from a lost specimen.[26]
Dorateuthis D. syriaca A plesioteuthid coleoid.[5]
 
?Glyphiteuthis G. libanotica A trachyteuthid coleoid.[5]
Muniericeras M. blanfordianum A muniericeratid ammonoid.[5]
Palaeoctopus P. newboldi An octopus.  
Syrionautilus S. libanoticus A cymatoceratid nautiloid.[27]
Texanites T. texanus A collignoniceratid ammonoid.[5]  

References

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  1. ^ a b c d George, Hady; Bazzi, Mohamad; El Hossny, Tamara; Ashraf, Nida; Abi Saad, Pierre; Clements, Thomas (2024-09-02). "The famous fish beds of Lebanon: the Upper Cretaceous Lagerstätten of Haqel, Hjoula, Nammoura and Sahel Aalma". Journal of the Geological Society. 181 (5). doi:10.1144/jgs2023-210. ISSN 0016-7649.
  2. ^ Walley, C. D. (1997). "The Lithostratigraphy of Lebanon: A Review 1". Lebanese Science Bulletin. 10 (1).
  3. ^ a b Audo, Denis; Charbonnier, Sylvain (2011). "The crestbearing shrimps from the Sahel Alma Lagerstatte (Late Cretaceous, Lebanon)". Acta Palaeontologica Polonica. doi:10.4202/app.2011.0056. ISSN 0567-7920.
  4. ^ Capasso, Luigi (2017). "The history and the situation of the world famous fossil fish quarries in Lebanon". Bollettino del Museo Civico di Storia Naturale di Verona. 41: 53–76.
  5. ^ a b c d e Jattiot, Romain; Brayard, Arnaud; Fara, Emmanuel; Charbonnier, Sylvain (2015). "Gladius-bearing coleoids from the Upper Cretaceous Lebanese Lagerstätten: diversity, morphology, and phylogenetic implications". Journal of Paleontology. 89 (1): 148–167. Bibcode:2015JPal...89..148J. doi:10.1017/jpa.2014.13. ISSN 0022-3360.
  6. ^ Pradel, Alan; Denton, John S. S.; Janvier, Philippe; Maisey, John G., eds. (2021). Ancient fishes and their living relatives: a tribute to John G. Maisey. München: Verlag Dr. Friedrich Pfeil. ISBN 978-3-89937-269-4.
  7. ^ Cappetta, Henri (1980-01-01). "Les sélaciens du Crétacé supérieur du Liban. II: Batoïdes". Palaeontographica Abteilung A (in German): 149–229.
  8. ^ Claeson, Kerin M.; Underwood, Charlie J.; Ward, David J. (2013). "† Tingitanius tenuimandibulus, a new platyrhinid batoid from the Turonian (Cretaceous) of Morocco and the cretaceous radiation of the Platyrhinidae". Journal of Vertebrate Paleontology. 33 (5): 1019–1036. doi:10.1080/02724634.2013.767266. ISSN 0272-4634.
  9. ^ Last, Peter R.; Yearsley, Gordon K. (2002). "Zoogeography and relationships of Australasian skates (Chondrichthyes: Rajidae)". Journal of Biogeography. 29 (12): 1627–1641. doi:10.1046/j.1365-2699.2002.00793.x. ISSN 0305-0270.
  10. ^ Villalobos-Segura, Eduardo; Underwood, Charlie J. (2020-05-03). "Radiation and Divergence Times of BatoideaCitation for this article: Villalobos-Segura, E., and C. J. Underwood. 2020. Radiation and divergence times of Batoidea. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2020.1777147". Journal of Vertebrate Paleontology. 40 (3). doi:10.1080/02724634.2020.1777147. ISSN 0272-4634.
  11. ^ a b Georges Kachacha, Gilles Cuny (2017). "Revision of the fossil batomorphs from the Cretaceous of Lebanon, and their impact on our understanding of the early step of the evolution of the clade". Research & Knowledge. 3: 2. doi:10.14456/RANDK.2017.22.
  12. ^ "The Paleobiology Database". paleobiodb.org. Retrieved 2024-08-05.
  13. ^ Murray, Alison M. (2014). "Mid-Cretaceous acanthomorph fishes with the description of a new species from the Turonian of Lac des Bois, Northwest Territories, Canada". Vertebrate Anatomy Morphology Palaeontology. 1: 101–115. doi:10.18435/B5CC78. ISSN 2292-1389.
  14. ^ Geology, British Museum (Natural History) Department of; Woodward, Arthur Smith (1901). Catalogue of the Fossil Fishes in the British Museum (Natural History): Actinopterygian Teleostomi of the suborders Isospondyli (in part), Ostariophysi, Apodes, Percesoces, Hemibranchii, Acanthopterygii, and Anacanthini. order of the Trustees.
  15. ^ a b Silva, Hilda M. A.; Gallo, Valéria (2011). "Taxonomic review and phylogenetic analysis of Enchodontoidei (Teleostei: Aulopiformes)". Anais da Academia Brasileira de Ciências. 83: 483–511. doi:10.1590/S0001-37652011000200010. ISSN 0001-3765.
  16. ^ Belouze, Anne (2002). "Compréhension morphologique et phylogénétique des taxons actuels et fossiles rapportés aux anguilliformes («poissons», téléostéens)". Travaux et Documents des Laboratoires de Géologie de Lyon. 158 (1): 3–401.
  17. ^ a b Near, Thomas J.; Thacker, Christine E. (2024-04-18). "Phylogenetic Classification of Living and Fossil Ray-Finned Fishes (Actinopterygii)". Bulletin of the Peabody Museum of Natural History. 65 (1). doi:10.3374/014.065.0101. ISSN 0079-032X.
  18. ^ "PBDB Taxon". paleobiodb.org. Retrieved 2024-08-05.
  19. ^ Taverne, Louis; Filleul, Arnaud (2003). "Osteology and relationships of the genus Spaniodon (Teleostei, Salmoniformes) from the Santonian (Upper Cretaceous) of Lebanon". Palaeontology. 46 (5): 927–944. doi:10.1111/1475-4983.00327. ISSN 0031-0239.
  20. ^ Sylvain Charbonnier; Denis Audo; Alessandro Garassino; Matúš Hyžný (2017). Fossil Crustacea of Lebanon. National Museum of Natural History. pp. 1–252. ISBN 978-2-85653-785-5.
  21. ^ Petit, Gilles; Charbonnier, Sylvain (2012). "Fossil sponge gemmules, epibionts of Carpopenaeus garassinoi n. sp. (Crustacea, Decapoda) from the Sahel Alma Lagerstätte (Late Cretaceous, Lebanon)". Geodiversitas. 34 (2): 359–372. doi:10.5252/g2012n2a6. ISSN 1280-9659.
  22. ^ Feldmann, Rodney M. (2009-01-01). "A New Cirolanid Isopod (Crustacea) from the Cretaceous of Lebanon: Dermoliths Document the Pre-Molt Condition". Journal of Crustacean Biology. 29 (3): 373–378. doi:10.1651/08-3096.1. ISSN 0278-0372.
  23. ^ a b c d e Charbonnier, Sylvain; Teruzzi, Giorgio; Audo, Denis; Lasseron, Maxime; Haug, Carolin; Haug, Joachim T. (2017). "New thylacocephalans from the Cretaceous Lagerstätten of Lebanon". Bulletin de la Société géologique de France. 188 (3): 19. doi:10.1051/bsgf/2017176. ISSN 0037-9409.
  24. ^ Gale, Andrew Scott (2016-08-02). "Origin and phylogeny of the Cretaceous thoracican cirripede family Stramentidae". Journal of Systematic Palaeontology. 14 (8): 653–702. doi:10.1080/14772019.2015.1091149. ISSN 1477-2019.
  25. ^ a b Audo, Denis; Winkler, Norbert; Charbonnier, Sylvain (2021-04-15). "Pseudodrobna natator n. comb., a new link between crustacean faunas from the Jurassic of Germany and Cretaceous of Lebanon". Geodiversitas. 43 (8). doi:10.5252/geodiversitas2021v43a8. ISSN 1280-9659.
  26. ^ Fuchs; Larson, Dirk; Neal L (March 2011). "Diversity, Morphology, and Phylogeny of Coleoid Cephalopods from the Upper Cretaceous Plattenkalks of Lebanon–Part I: Prototeuthidina". Journal of Paleontology. 85 (2): 234–249.
  27. ^ "PBDB Collection". paleobiodb.org. Retrieved 2024-08-05.