View source for Elrhaz Formation

{{Infobox Rockunit
| name           = Elrhaz Formation
| image          = Gadoufaoua.png
| caption        = Outcrops of the formation near Gadoufaoua
| type           = [[Geological formation]]
| age            = [[Early Cretaceous]] ([[Barremian]] to [[Albian]]), {{fossilrange|125|112|earliest=125}}
| period         = Albian
| prilithology   = [[Sandstone]]
| otherlithology =
| namedfor       =
| namedby        =
| region         = [[Africa]]
| country        = {{flag|Niger}}
| coordinates    = {{coord|16.8|N|9.5|E|display=inline,title}}
| paleocoordinates = {{coord|3.1|N|4.9|E|display=inline}}
| unitof         = [[Tegama Group]]
| subunits       =
| underlies      = [[Echkar Formation]]
| overlies       = [[Tazolé Formation]]
| thickness      =
| extent         = [[Tenere|Tenere desert]]
| area           =
| map            =
| map_caption    =
}}

The '''Elrhaz Formation''' is a geological [[Formation (geology)|formation]] in [[Niger]], [[West Africa]].

Its strata date back to the [[Early Cretaceous]], about 125 to 112 million years ago. Dinosaur remains are among the fossils that have been recovered from the formation, alongside those of multiple species of crocodyliformes.

== Gadoufaoua ==
[[File:African pterosaur.jpg|thumb|left|Reconstructed skeleton of an [[anhanguerid]] from the formation]] 
'''Gadoufaoua''' ([[Tuareg language|Tuareg]] for "the place where camels fear to go") is a site within the Elrhaz Formation (located at {{coord|16|50|N|9|25|E|region:NE-1_type:landmark_source:kolossus-dewiki|display=inline}}) in the [[Tenere]] desert of [[Niger]] known for its extensive [[fossil]] graveyard. It is where remains of ''[[Sarcosuchus imperator]]'', popularly known as [[SuperCroc]], were found (by [[Paul Sereno]] in 1997, for example), including vertebrae, limb bones, armor plates, jaws, and a nearly complete {{convert|6|ft|m}} skull.

[[File:Erlhaz Formation.jpg|right|thumb|Dinosaurs of Elrhaz formation]]
[[File:Claw of Spinosaur.jpg|right|thumb|The claw of Spinosaur from the formation]]

Gadoufaoua is very hot and dry.  However, it is supposed that millions of years ago, Gadoufaoua had trees, plants, and wide rivers.  The river covered the remains of dead animals, the fossilized remains of which were protected by the drying rivers over millions of years.<ref>[http://www.voanews.com/specialenglish/Archive/a-2001-11-12-2-1.cfm SCIENCE IN THE NEWS - Nov. 13: Digest - 12 November 2001 Voice of America]</ref>

== Vertebrate paleofauna ==

=== Chondrichthyes ===
{| class="wikitable"
! colspan="5" |[[Chondrichthyes]]
|-
! Genus !! Species !! Material !! Notes !! Images
|-
|''[[Hybodus]]''<ref name=Taquet1970/>
|''H. sp.''
|Dorsal spines<ref name=Taquet1970/>
|
|[[File:Hybodus model.jpg|center|150px]]
|}

=== Sarcopterygii ===
{| class="wikitable"
! colspan="5" |[[Sarcopterygii]]
|-
! Genus !! Species !! Material !! Notes !! Images
|-
|''[[Asiatoceratodus]]''<ref name="Taquet1970" />
|''A. tiguidiensis<ref name="Taquet1970" />''
|
|[[Dipnomorpha|Dipnomorph]] fish. Originally described as ''Ceratodus tiguidiensis'',<ref>N. Tabaste. 1963. Étude derestes de poissons du Crétacé saharien [Study of fish remains from the Saharan Cretaceous]. Mélanges Ichthyologiques Dédiés à la Mémoire d’Achille Valenciennes (1794–1865). Mémoires de l’Institute Français d’Afrique Noire 68:437-485</ref> assigned to ''[[Arganodus]]'' by M. Martin (1984)<ref>Martin, M., 1984. Révision des Arganodontidés et des Néocératodontidés (Dipnoi,
Ceratodontiformes) du Crétacé africain. Neues Jb. Geol. Paläontol. Abh. 169, 225–260.</ref> and reassigned by Kemp (1998) to the genus ''Asiatoceratodus''.<ref>Kemp, A. 1998. Skull structure in post-paleozoic lungfish. Journal of Vertebrate Paleontology, 18(1): 43-63.</ref>
|
|-
|[[Mawsonia (fish)|''Mawsonia'']]<ref name="fossilworks.org">{{Cite web |title=Fossilworks: Gateway to the Paleobiology Database |url=http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=37200 |access-date=2022-05-16 |website=www.fossilworks.org}}</ref>
|''M. tegamensis''<ref name="fossilworks.org"/>
|
|A small species.<ref>{{Cite book |last=Taquet |first=Philippe |url=http://archive.org/details/dinosaurimpressi00taqu |title=Dinosaur impressions : postcards from a paleontologist |date=1998 |publisher=Cambridge ; New York : Cambridge University Press |others=Internet Archive |isbn=978-0-521-58372-5}}</ref>
|[[File:MawsoniaDB16 (cropped).jpg|center|150px]]
|-
|''[[Neoceratodus]]''<ref name=Taquet1970/>
|''[[Neoceratodus africanus|N. africanus]]''<ref name=Taquet1970/>
|Tooth plates.<ref>Federico Fanti, Gabriele Larocca Conte, Luana Angelicola, Andrea Cau, 2016. "Why so many dipnoans? A multidisciplinary approach on the Lower Cretaceous lungfish record from Tunisia." Palaeogeography, Palaeoclimatology, Palaeoecology. 449: 255-265. DOI:10.1016/j.palaeo.2016.02.024</ref>
|[[Dipnomorpha|Dipnomorph]] fish. Originally described as ''Ceratodus africanus'', assigned to ''Neoceratodus'' by M. Martin, 1982.<ref name=Martin1982>M. Martin. 1982. Nouvelles données sur la phylogénie et la systématique des dipneustes postpaléozoïques [New data on the phylogeny and systematics of post-Paleozoic dipnoans]. Comptes Rendues de l'Academie des Sciences, Paris, Série II 294:611-614</ref>
|[[File:Neoceratodus forsteri Cologne Zoo.jpg|center|thumb|150px|''[[Neoceratodus forsteri]]'', a modern species]]
|}

=== Actinopterygii ===
{| class="wikitable"
! colspan="5" |[[Actinopterygii]]
|-
! Genus !! Species !! Material !! Notes !! Images
|-
|''[[Pliodetes]]''<ref name=Wenz>S. Wenz. 1999. Pliodetes nigeriensis, gen. nov. et. sp. nov., a new semionotid fish from the Lower Cretaceous of Gadoufaoua (Niger Republic): phylogenetic comments. In G. Arratia & H.-P. Schultz (ed.), Mesozoic Fishes 2—Systematics and Fossil Record 107-120</ref> 
|''P. nigeriensis''<ref name=Wenz/>
|Skull and postcranial material including body scales.<ref name=Lopez>A. López-Arbarello. 2012. [https://www.researchgate.net/publication/229162077_Phylogenetic_Interrelationships_of_Ginglymodian_Fishes_Actinopterygii_Neopterygii Phylogenetic interrelationships of ginglymodian fishes (Actinopterygii: Neopterygii)]. PLoS ONE</ref>
|Originally thought to be a [[Semionotidae|semionotid]], later assigned to [[Lepisosteoidei]].<ref name=Lopez/>
|[[File:Scales of Pliodetes nigeriensis.png|center|150px]]
|-
|[[Pycnodontidae]] indet.<ref name=Taquet1970>"On the dinosaurian and crocodilian locality of Gadoufaoua (Republic of
Niger)" ([https://paleoglot.org/files/Taquet_2070.pdf PDF]). From Mr. Philippe Taquet (1970), presented by Mr. Jean Piveteau.</ref>
|Indeterminate
|
|
|
|}

=== Testudines ===
{| class="wikitable"
! colspan="5" |[[Testudines]]
|-
! Genus !! Species !! Material !! Notes !! Images
|-
|''[[Francemys]]''<ref name="Perez_Garcia2019" />
|''F. gadoufaouaensis''<ref name="Perez_Garcia2019" />
|"Shell of a juvenile individual and several articulated and disarticulated plates."<ref name="Perez_Garcia2019" />
|[[Pelomedusoides|Pelomedusoid]] turtle. Named in honour of France de Lapparent de Broin.<ref name="Perez_Garcia2019" />
|
|-
|''[[Taquetochelys]]''<ref name="Broin1980" />
|''T. decorata''<ref name="Broin1980" />
|A few disarticulated plates and nearly complete skeleton.<ref name="Perez_Garcia2018">{{cite journal |last1=Pérez-García |first1=Adán |title= Identification of the Lower Cretaceous pleurodiran turtle Taquetochelys decorata as the only African araripemydid species |journal=Comptes Rendus Palevol |date=2018 |volume=18 |pages=24–32 |doi=10.1016/j.crpv.2018.04.004 |language=en |issn=1631-0683|doi-access=free }}</ref>
|[[Araripemydidae|Araripemydid]] turtle, similar in shell size to South American ''[[Araripemys]]'' (20–30&nbsp;cm). ''Laganemys tenerensis'' was synonymysed with ''Taquetochelys'' by Pérez-García, 2018.<ref name="Perez_Garcia2018" />
|
|-
|''[[Teneremys]]''<ref name=Broin1980>F. de Broin. 1980. Les tortues de Gadoufaoua (Aptien du Niger); aperçu sur la Paléobiogéographie des Pelomedusidae (Pleurodira). Mémoires de la Société Géologique de France</ref>
|''T. lapparenti''<ref name=Broin1980/>
|"Several relatively complete skeletons."<ref name=Perez_Garcia2019>{{cite journal |last1=Pérez-García |first1=Adán |title=The African Aptian Francemys gadoufaouaensis gen. et sp. nov.: New data on the early diversification of Pelomedusoides (Testudines, Pleurodira) in northern Gondwana |journal=Cretaceous Research |date=1 October 2019 |volume=102 |pages=112–126 |doi=10.1016/j.cretres.2019.06.003 |language=en |issn=0195-6671|doi-access=free |bibcode=2019CrRes.102..112P }}</ref>
|
|
|}

=== Crocodyliformes ===
{| class="wikitable" align="center"
|-
! colspan="5" align="center" | '''[[Crocodyliform]]es'''
|-
! Genus !! Species !! Material !! Notes !! Images
|-
| ''[[Anatosuchus]]''<ref name="elrhaz" />
| ''A. minor''<ref name="elrhaz" />
| "Nearly complete skull"
|
| [[File:Anatosuchus BW.jpg|center|150px]]
|-
| ''[[Araripesuchus]]''<ref name="elrhaz">"68.1 Departement D'Agedez, Niger; 1. Elrhaz Formation," in Weishampel, et al. (2004). Page 572</ref>
| ''A. wegeneri''<ref name="elrhaz" />
| "Nearly complete skull"
|
| [[File:Araripesuchus wegeneri.jpg|center|150px]]
|-
| ''[[Sarcosuchus]]''<ref>Sereno et al., 2011</ref>
| ''S. imperator''
| "Partial skeletons, numerous skulls"
| 
| [[File:Sarcosuchus Illustration.jpg|center|150px]]
|-
| ''[[Stolokrosuchus]]''
| ''S. lapparenti''
| 
| 
| 
|-
|}

=== Dinosaurs ===
==== Ornithischians ====
{| class="wikitable" align="center"
|-
! colspan="6" align="center" | '''[[Ornithischian]]s'''
|-
! Genus !! Species !! Material !! Notes !! Images
|-
| ''[[Elrhazosaurus]]''<ref name="elrhaz" />
| ''E. nigeriensis''<ref name="elrhaz" />
| "Femora."<ref name="table-19-1-415">"Table 19.1," in Weishampel, et al. (2004). Page 415.</ref>
| A dryosaurid
| [[File:Elrhazosaurus NT.png|center|150px]]
|-
| ''[[Lurdusaurus]]''<ref name="elrhaz"/>
| ''L. arenatus''<ref name="elrhaz" />
| "Partial skull, fragmentary postcranial skeleton."<ref name="table-19-1-416">"Table 19.1," in Weishampel, et al. (2004). Page 416.</ref>
|
| [[File:Lurdusaurus1.jpg|center|150px]]
|-
| ''[[Ouranosaurus]]''<ref name="elrhaz" />
| ''O. nigeriensis''<ref name="elrhaz" />
| "Skull and poscrania, second skeleton."<ref name="table-19-1-417">"Table 19.1," in Weishampel, et al. (2004). Page 417.</ref>
|
| [[File:Ouranosaurus nigeriensis restoration.png|center|150px]]
|-
|}

==== Theropods ====
{| class="wikitable" align="center"
|-
! colspan="6" align="center" | '''[[Theropoda|Theropods]]'''
|-
! Genus !! Species !! Material !! Notes !! Images
|-
| ''[[Afromimus]]''
| ''A. tenerensis''
| "caudal vertebrae, chevrons and portions of the right hind limb"<ref>Sereno, P. (2017). "Early Cretaceous ornithomimosaurs (Dinosauria: Coelurosauria) from Africa". Ameghiniana. 54 (5): 576–616. doi:10.5710/AMGH.23.10.2017.3155.</ref>
| A [[Noasaurid]]
| [[File:Afromimus LM (gray).png|center|150px]]
|-
| ''[[Eocarcharia]]''<ref name="elrhaz" />
| ''E. dinops''<ref>Sereno & Brusatte, 2008</ref>
| "Partial skull and postcranial remains."<ref name="table-4-1-73">"Table 4.1," in Weishampel, et al. (2004). Page 73.</ref>
| Carcharodontosaurid
| [[File:Eocarcharia, improved.png|center|150px]]
|-
| ''[[Kryptops]]''<ref name="elrhaz" />
| ''K. palaios''<ref name="elrhaz" />
| Postcranial skeleton and partial skull.<ref>"Table 4.1," in Weishampel, et al. (2008). Page 72.</ref>
| Abelisaurid
| [[File:Kryptops life restoration.jpg|center|150px]]
|-
| ''[[Suchomimus]]''<ref name="elrhaz" />
| ''S. tenerensis''<ref name="elrhaz" />
| Partial skull and associated skeleton.<ref>"Table 4.1," in Weishampel, et al. (2004). Page 72.</ref>
| A second, spinosaurid found in the formation, ''[[Cristatusaurus]]'', is considered either a separate species or a synonym to'' Suchomimus''<ref>Rauhut, O.W.M. (2003). "The interrelationships and evolution of basal theropod dinosaurs". Special Papers in Palaeontology 69: 1-213.</ref>
| [[File:Suchomimus2.jpg|center|150px]]
|}

==== Sauropods ====
{| class="wikitable"
|+
! colspan="5" align="center" | [[Sauropoda|Sauropods]]
|-
! Genus !! Species !! Material !! Notes !! Images
|-
| ''[[Nigersaurus]]''
| ''N. taqueti''
| Skull and skeletal remains
| A [[rebbachisaurid]].
| [[File:Nigersaurus BW.jpg|center|150px]]
|}

== See also ==
* [[List of dinosaur-bearing rock formations]]
* [[Crato Formation]]
* [[Romualdo Formation]]

== References ==
{{Reflist}}

=== Bibliography ===
* {{citation |last1=Sereno |first1=P. C. |last2=Larsson |first2=H. C. |last3=Sidor |first3=C. A. |last4=Gado |first4=B. |year=2001 |title=The giant crocodyliform ''Sarcosuchus'' from the Cretaceous of Africa |journal=[[Science (journal)|Science]] |volume=294 |issue=5546 |pages=1516–1519 |doi=10.1126/science.1066521 |pmid=11679634 |bibcode=2001Sci...294.1516S |author1-link=Paul Sereno }}{{issn|0036-8075}}{{PMID|11679634}}
* {{citation |last1=Sereno |first1=Paul C. |last2=Brusatte |first2=Stephen L. |year=2008 |title=Basal abelisaurid and carcharodontosaurid theropods from the Lower Cretaceous Elrhaz Formation of Niger |url=https://www.research.ed.ac.uk/portal/files/8231129/PDF_SerenoBrusatte2008NigerTheropods.pdf |journal=[[Acta Palaeontologica Polonica]] |volume=53 |pages=15–49 |doi=10.4202/app.2008.0102 |accessdate=2018-10-06 |author1-link=Paul Sereno }}
* {{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 |accessdate=2019-02-21 |isbn=0-520-24209-2 |author1-link=David B. Weishampel }}

== Further reading ==
* P. M. Galton and P. Taquet. 1982. ''Valdosaurus'', a hypsilophodontid dinosaur from the Lower Cretaceous of Europe and Africa. Géobios 15(2):147-159
* H. C. E. Larsson and B. Gado. 2000. A new Early Cretaceous crocodyliform from Niger. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 217(1):131-141
* P. C. Sereno and S. J. ElShafie. 2013. A New Long-Necked Turtle, ''Laganemys tenerensis'' (Pleurodira: Araripemydidae), from the Elrhaz Formation (Aptian–Albian) of Niger. In D. B. Brinkman, P. A. Holroyd, J. D. Gardner (eds.), Morphology and Evolution of Turtles 215–250
* P. C. Sereno and H. C. E. Larsson. 2009. Cretaceous crocodyliformes from the Sahara. ZooKeys 28:1-143
* P. C. Sereno, A. L. Beck, D. B. Dutheil, B. Gado, H. C. E. Larsson, G. H. Lyon, J. D. Marcot, O. W. M. Rauhut, R. W. Sadleir, C. A. Sidor, D. D. Varricchio, G. P. Wilson, and J. A. Wilson. 1998. A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids. Science 282:1298-1302

[[Category:Geologic formations of Niger]]
[[Category:Upper Cretaceous Series of Africa]]
[[Category:Cretaceous Niger]]
[[Category:Albian Stage]]
[[Category:Sandstone formations]]
[[Category:Fluvial deposits]]
[[Category:Paleontology in Niger]]
[[Category:Cretaceous paleontological sites of Africa]]