{{Short description|Geologic formation in Niger}} {{Infobox rockunit | name = In Beceten Formation | image = | caption = | type = Geological formation | age = Coniacian-Santonian | period = Santonian | prilithology = Limestone, sandstone | otherlithology = Shale | namedfor = | namedby = | region = Tahoua | country = Niger | coordinates = {{coord|15.1|N|6.0|E|display=inline,title}} | paleocoordinates = {{coord|1.7|N|0.9|E|display=inline}} | unitof = | subunits = | underlies = Igdaman Group | overlies = White Limestone Formation | thickness = | extent = Iullemmeden Basin | area = | map = {{Location map+ | Niger | relief = 1 | width = 250 | float = center | places = {{Location map~ | Niger | lat_deg = 15.1 | lon_deg = 6.0 | mark = Lightgreen pog.svg | marksize = 12 }} }} | map_caption = }} The '''In Beceten Formation''', also '''Beceten''' or '''Ibecten''' is a Coniacian to Santonian geologic formation in the Iullemmeden Basin of Niger. It has yielded a diverse fauna and some angiosperms.<ref name="de Broin et al. 1974">{{cite journal |last1=DE |first1=BROIN |last2=E |first2=BUFFETAUT |last3=JC |first3=KOENIGUER |last4=JC |first4=RAGE |last5=D |first5=RUSSELL |last6=P |first6=TAQUET |last7=C |first7=VERGNAUD GRAZZINI |last8=C |first8=WENZ |title=LA FAUNE DE VERTEBRES CONTINENTAUX DU GISEMENT D'IN BECETEN (SENONIEN DU NIGER). |journal=La Faune de Vertebres Continentaux du Gisement d'In Beceten (Senonien du Niger). |date=1974 |volume=279 |pages=469–472 |url=https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=PASCALGEODEBRGM7520012195}}</ref> Among others, it has yielded polypterifoms,<ref name="Gayet & Meunier 1996">{{cite journal |last1=GAYET |first1=M |last2=MEUNIER |first2=F. J. |title=Nouveaux Polypteriformes du gisement coniacien-sénonien d'In Becetem (Niger) |journal=Nouveaux Polypteriformes du gisement coniacien-sénonien d'In Becetem (Niger) |date=1996 |volume=322 |issue=8 |pages=701–707 |url=https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=3048354 |issn=1251-8050}}</ref> urodeles,<ref name="Gardner & Rage 2016">{{cite journal |last1=Gardner |first1=James D. |last2=Rage |first2=Jean-Claude |title=The fossil record of lissamphibians from Africa, Madagascar, and the Arabian Plate |journal=Palaeobiodiversity and Palaeoenvironments |date=1 March 2016 |volume=96 |issue=1 |pages=169–220 |doi=10.1007/s12549-015-0221-0 |bibcode=2016PdPe...96..169G |language=en |issn=1867-1608}}</ref> anurans,<ref name="Báez & Rage 1998">{{cite journal |last1=Báez |first1=A. M. |last2=Rage |first2=J.-C. |title=Pipid frogs from the upper cretaceous of in beceten, niger |journal=Palaeontology |date=1998 |volume=41 |issue=4 |pages=669–691 |url=https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310239_v41_n4_p669_Baez}}</ref><ref name="Lemierre et al. 2023">{{cite journal |last1=Lemierre |first1=Alfred |last2=Bailon |first2=Salvador |last3=Folie |first3=Annelise |last4=Laurin |first4=Michel |title=A new pipid from the Cretaceous of Africa (In Becetèn, Niger) and early evolution of the Pipidae |journal=Journal of Systematic Palaeontology |date=January 2023 |volume=21 |issue=1 |doi=10.1080/14772019.2023.2266428 |bibcode=2023JSPal..2166428L |language=en |issn=1477-2019}}</ref><ref name="Lemierre et al. 2025">{{cite journal |last1=Lemierre |first1=Alfred |last2=Bailon |first2=Salvador |last3=Folie |first3=Annelise |last4=Laurin |first4=Michel |title=New pipimorphs from the Late Cretaceous of Niger |journal=Annales de Paléontologie |date=1 April 2025 |volume=111 |issue=2 |article-number=102751 |doi=10.1016/j.annpal.2024.102751 |issn=0753-3969}}</ref> and turtles.<ref name="De Lapparen 2000">{{cite journal |last1=De Lapparent De Broin |first1=France |last2=Broin |first2=France De Lapparent De |title=African chelonians from the Jurassic to the present: phases of development and preliminary catalogue of the fossil record |journal=Palaeontologia Africana |date=2000 |volume=36 |pages=43–82 |url=https://bionames.org/references/bd1dc11b677a1f0d8faae180c7583f7c |issn=0078-8554}}</ref> Dinosaur remains are among the other fossils that have been recovered from the formation, although none have yet been referred to a specific genus.<ref name="dinosaurdistribution">Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.</ref> The lithology primarily consists of clays, fine limestones and sandy clays.<ref>{{Cite journal|last1=Moody|first1=R.T.J.|last2=Sutcliffe|first2=P.J.C.|date=April 1991|title=The Cretaceous deposits of the Iullemmeden Basin of Niger, central West Africa|journal=Cretaceous Research|volume=12|issue=2|pages=137–157|doi=10.1016/s0195-6671(05)80021-7|bibcode=1991CrRes..12..137M |issn=0195-6671}}</ref><ref>{{Cite journal|last1=Meunier|first1=Louise M V|last2=Larsson|first2=Hans C E|date=2017-10-26|title=''Trematochampsa taqueti'' as a nomen dubium and the crocodyliform diversity of the Upper Cretaceous In Beceten Formation of Niger|journal=Zoological Journal of the Linnean Society|volume=182|issue=3|pages=659–680|doi=10.1093/zoolinnean/zlx061|issn=0024-4082}}</ref>
== Fossil content == The following fossils have been reported from the formation:<ref>[https://paleobiodb.org/classic/displayCollResults?collection_no=48867 In Beceten] at Fossilworks.org</ref> ;Fish: * ''Amia sp.'' * ''Stromerichthys sp.'' * Lepisosteidae indet.
;Reptiles {{divcol|colwidth=20em}} * ''Erymnochelys madagascariensis'' * ''Madtsoia aff. madagascariensis'' * ''Trematochampsa taqueti'' * ''Libycosuchus sp.'' * Carnosauria indet. * Goniopholididae indet. * Lacertilia indet. * Pelomedusidae indet. * Serpentes indet. * Titanosaurinae indet. {{colend}}
;Amphibians {{divcol|colwidth=20em}} * ''Pachycentrata taqueti'' * ''Inbecetenanura ragei'' * Ranidae indet. * Urodela indet. {{colend}}
;Dipnoi * ''Ceratodus sp.'' * ''Protopterus sp.''
;Flora * Dicotyledonae
== See also == * List of dinosaur-bearing rock formations ** List of stratigraphic units with indeterminate dinosaur fossils * Lists of fossiliferous stratigraphic units in Africa ** List of fossiliferous stratigraphic units in Niger * Geology of Niger
== References == {{Reflist}}
{{clear}}
=== Bibliography === * {{citation |last1=Weishampel |first1=David B. |author2-link=Peter Dodson |last2=Dodson |first2=Peter |author3-link=Halszka Osmólska |last3=Osmólska |first3=Halszka |year=2004 |title=The Dinosauria, 2nd edition |url=https://books.google.com/books?id=vtZFDb_iw40C |publisher=Berkeley: University of California Press |pages=1–880 |access-date=2019-02-21 |isbn=0-520-24209-2 |author1-link=David B. Weishampel }}
== Further reading == * F. de Broin, E. Buffetaut, J.-C. Koeniguer, J.-C. Rage, D. E. Russell, P. Taquet, C. Vergnaud-Grazzini and S. Wenz. 1974. La fauna de Vertébrés continentaux du gisement d'In Beceten (Sénonien du Niger) [The continental vertebrate fauna from the In Beceten locality (Senonian of Niger)]. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences de Paris, série D 279:469-472
Category:Geologic formations of Niger Category:Upper Cretaceous Series of Africa Category:Cretaceous Niger Category:Coniacian Stage Category:Santonian Stage Category:Shale formations Category:Limestone formations Category:Sandstone formations Category:Fluvial deposits Category:Lacustrine deposits Category:Paleontology in Niger Formations