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Elrhaz Formation#Gadoufaoua

{{Short description|Geological formation in Niger, West Africa}}

{{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 = 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 desert

| area =

| map =

| map_caption =

}}

The Elrhaz Formation is a geological 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 from the formation]]

Gadoufaoua (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

File:Claw of Spinosaur.jpg

Gadoufaoua is very hot and dry. Based on the sedimentary and fossil record, Gadoufaoua had trees, plants, and wide rivers 112 million years ago. The river covered the remains of dead animals, the fossilized remains of which were protected by the drying rivers over millions of years.[https://web.archive.org/web/20050620052229/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]

Vertebrate paleofauna

= Chondrichthyes =

class="wikitable"

! colspan="5" |Chondrichthyes

GenusSpeciesMaterialNotesImages
Hybodus

|H. sp.

|Dorsal spines

|

|File:Hybodus model.jpg

= Sarcopterygii =

class="wikitable"

! colspan="5" |Sarcopterygii

GenusSpeciesMaterialNotesImages
Asiatoceratodus

|A. tiguidiensis

|

|Dipnomorph fish. Originally described as Ceratodus tiguidiensis,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 assigned to Arganodus by M. Martin (1984)Martin, M., 1984. Révision des Arganodontidés et des Néocératodontidés (Dipnoi,

Ceratodontiformes) du Crétacé africain. Neues Jb. Geol. Paläontol. Abh. 169, 225–260. and reassigned by Kemp (1998) to the genus Asiatoceratodus.Kemp, A. 1998. Skull structure in post-paleozoic lungfish. Journal of Vertebrate Paleontology, 18(1): 43-63.

|

Mawsonia{{Cite web |title=Fossilworks: Gateway to the Paleobiology Database |url=https://paleobiodb.org/classic/displayCollResults?collection_no=37200 |access-date=2022-05-16 |website=Paleobiology Database}}

|M. tegamensis

|

|A small species.{{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}}

|File:MawsoniaDB16 (cropped).jpg

Neoceratodus

|N. africanus

|Tooth plates.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

|Dipnomorph fish. Originally described as Ceratodus africanus, assigned to Neoceratodus by M. Martin, 1982.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

|File:Neoceratodus forsteri Cologne Zoo.jpg, a modern species]]

= Actinopterygii =

class="wikitable"

! colspan="5" |Actinopterygii

GenusSpeciesMaterialNotesImages
PliodetesS. 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

|P. nigeriensis

|Skull and postcranial material including body scales.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

|Originally thought to be a semionotid, later assigned to Lepisosteoidei.

|File:Scales of Pliodetes nigeriensis.png

Pycnodontidae indet."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.

|Indeterminate

|

|

|

= Testudines =

class="wikitable"

! colspan="5" |Testudines

GenusSpeciesMaterialNotesImages
Francemys

|F. gadoufaouaensis

|"Shell of a juvenile individual and several articulated and disarticulated plates."

|Pelomedusoid turtle. Named in honour of France de Lapparent de Broin.

|

Taquetochelys

|T. decorata

|A few disarticulated plates and nearly complete skeleton.{{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 }}

|Araripemydid turtle, similar in shell size to South American Araripemys (20–30 cm). Laganemys tenerensis was synonymysed with Taquetochelys by Pérez-García, 2018.

|

TeneremysF. de Broin. 1980. Les tortues de Gadoufaoua (Aptien du Niger); aperçu sur la Paléobiogéographie des Pelomedusidae (Pleurodira). Mémoires de la Société Géologique de France

|T. lapparenti

|"Several relatively complete skeletons."{{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 }}

|

|

= Crocodyliformes =

class="wikitable" align="center"
colspan="5" align="center" | Crocodyliformes
GenusSpeciesMaterialNotesImages
Anatosuchus

| A. minor

| "Nearly complete skull"

|

| File:Anatosuchus BW.jpg

Araripesuchus"68.1 Departement D'Agedez, Niger; 1. Elrhaz Formation," in Weishampel, et al. (2004). Page 572

| A. wegeneri

| "Nearly complete skull"

|

| File:Araripesuchus wegeneri.jpg

SarcosuchusSereno et al., 2011

| S. imperator

| "Partial skeletons, numerous skulls"

|

| File:Sarcosuchus Illustration.jpg

Stolokrosuchus

| S. lapparenti

|

|

|

= Dinosaurs =

== Ornithischians ==

class="wikitable" align="center"
colspan="6" align="center" | Ornithischians
GenusSpeciesMaterialNotesImages
Elrhazosaurus

| E. nigeriensis

| "Femora.""Table 19.1," in Weishampel, et al. (2004). Page 415.

| A dryosaurid

| File:Elrhazosaurus NT.png

Lurdusaurus

| L. arenatus

| "Partial skull, fragmentary postcranial skeleton.""Table 19.1," in Weishampel, et al. (2004). Page 416.

|

| File:Lurdusaurus1.jpg

Ouranosaurus

| O. nigeriensis

| "Skull and poscrania, second skeleton.""Table 19.1," in Weishampel, et al. (2004). Page 417.

|

| File:Ouranosaurus nigeriensis restoration.png

== Theropods ==

class="wikitable" align="center"
colspan="6" align="center" | Theropods
GenusSpeciesMaterialNotesImages
Afromimus

| A. tenerensis

| "caudal vertebrae, chevrons and portions of the right hind limb"Sereno, P. (2017). "Early Cretaceous ornithomimosaurs (Dinosauria: Coelurosauria) from Africa". Ameghiniana. 54 (5): 576–616. doi:10.5710/AMGH.23.10.2017.3155.

| A putative noasaurid{{cite journal |first1=M.A. |last1=Cerroni |first2=F.L. |last2=Agnolin |first3=F. |last3=Brissón Egli |first4=F.E. |last4=Novas |year=2019 |title=The phylogenetic position of Afromimus tenerensis Sereno, 2017 and its paleobiogeographical implications |journal=Journal of African Earth Sciences |volume=159 |pages=103572 |doi=10.1016/j.jafrearsci.2019.103572|bibcode=2019JAfES.15903572C |s2cid=201352476 }}

| File:Afromimus LM (gray).png

Cristatusaurus{{Cite journal|last1=Taquet|first1=Philippe|last2=Russell|first2=Dale A|date=1998|title=New data on spinosaurid dinosaurs from the early cretaceous of the Sahara|journal=Comptes Rendus de l'Académie des Sciences, Série IIA|language=en|volume=327|issue=5|pages=347–353|doi=10.1016/S1251-8050(98)80054-2|issn=1251-8050|bibcode=1998CRASE.327..347T}}

| C. lapparenti

| Jaw bones and vertebral fragments.

| A spinosaurid potentially synonymous with SuchomimusRauhut, O.W.M. (2003). "The interrelationships and evolution of basal theropod dinosaurs". Special Papers in Palaeontology 69: 1-213.

| File:Cristatusaurus_lapparenti_by_PaleoGeek.png

Eocarcharia

| E. dinopsSereno & Brusatte, 2008

| "Partial skull and postcranial remains.""Table 4.1," in Weishampel, et al. (2004). Page 73.

| Known from chimaeric remains; the holotype and skull roof material likely derive from a baryonychine spinosaurid, while the referred maxilla is from a carcharodontosaurid.{{Cite journal |last1=Cau |first1=Andrea |author1-link=Andrea Cau |last2=Paterna |first2=Alessandro |date=May 2025 |title=Beyond the Stromer's Riddle: the impact of lumping and splitting hypotheses on the systematics of the giant predatory dinosaurs from northern Africa |url=https://www.italianjournalofgeosciences.it/297/article-1220/beyond-the-stromer-s-riddle-the-impact-of-lumping-and-splitting-hypotheses-on-the-systematics-of-the-giant-predatory-dinosaurs-from-northern-africa.html |journal=Italian Journal of Geosciences |volume=144 |issue=2 |pages=1–24 |doi=10.3301/IJG.2025.10|url-access=subscription }}

| File:Eocarcharia, improved.png

Kryptops

| K. palaios

| Postcranial skeleton and partial skull."Table 4.1," in Weishampel, et al. (2008). Page 72.

| An abelisaurid

| File:Kryptops life restoration.jpg

Suchomimus

| S. tenerensis

| Partial skull and associated skeleton."Table 4.1," in Weishampel, et al. (2004). Page 72.

| A baryonychine spinosaurid

| File:Suchomimus2.jpg

== Sauropods ==

class="wikitable"

|+

! colspan="5" align="center" | Sauropods

GenusSpeciesMaterialNotesImages
Nigersaurus

| N. taqueti

| Skull and skeletal remains

| A rebbachisaurid.

| File:Nigersaurus BW.jpg

== Flora ==

class="wikitable"

|+

! colspan="5" align="center" | Plants

GenusSpeciesMaterialNotesImages
Paradoxopteris{{Cite web |title=Niveau des Innocents, Gadoufaoua (Cretaceous of Niger) |url=https://paleobiodb.org/classic/basicCollectionSearch?collection_no=37200 |access-date=2025-05-29 |website=paleobiodb.org}}

| P. stromeri

|

| A tree fern and member of Matoniaceae.

|

Protophyllocladoxylon

|P.chudeaui

|

|A conifer

|

See also

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 |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