Elrhaz Formation

The Elrhaz Formation is a geological formation in Niger, West Africa.

Elrhaz Formation
Stratigraphic range: Early Cretaceous (Barremian to Albian), 125–112 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Outcrops of the formation near Gadoufaoua
Type	Geological formation
Unit of	Tegama Group
Underlies	Echkar Formation
Overlies	Tazolé Formation
Lithology
Primary	Sandstone
Location
Coordinates	16.8°N 9.5°E / 16.8; 9.5
Approximate paleocoordinates	3.1°N 4.9°E / 3.1; 4.9
Region	Africa
Country	Niger
Extent	Tenere desert
Elrhaz Formation (Niger)

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

Reconstructed skeleton of an anhanguerid from the formation

Gadoufaoua (Tuareg for "the place where camels fear to go") is a site within the Elrhaz Formation (located at 16°50′N 9°25′E) 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 6 feet (1.8 m) skull.

Dinosaurs of Elrhaz formation

A spinosaurid claw from the Elrhaz formation

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.^[1]

Vertebrate paleofauna

Chondrichthyes

Chondrichthyes
Genus	Species	Material	Notes	Images
Hybodus[2]	H. sp.	Dorsal spines[2]

Sarcopterygii

Sarcopterygii
Genus	Species	Material	Notes	Images
Asiatoceratodus[2]	A. tiguidiensis[2]		Dipnomorph fish. Originally described as Ceratodus tiguidiensis,[3] assigned to Arganodus by M. Martin (1984)[4] and reassigned by Kemp (1998) to the genus Asiatoceratodus.[5]
Mawsonia[6]	M. tegamensis[6]		A small species.[7]
Neoceratodus[2]	N. africanus[2]	Tooth plates.[8]	Dipnomorph fish. Originally described as Ceratodus africanus, assigned to Neoceratodus by M. Martin, 1982.[9]	Neoceratodus forsteri, a modern species

Actinopterygii

Actinopterygii
Genus	Species	Material	Notes	Images
Pliodetes[10]	P. nigeriensis[10]	Skull and postcranial material including body scales.[11]	Originally thought to be a semionotid, later assigned to Lepisosteoidei.[11]
Pycnodontidae indet.[2]	Indeterminate

Testudines

Testudines
Genus	Species	Material	Notes	Images
Francemys[12]	F. gadoufaouaensis[12]	"Shell of a juvenile individual and several articulated and disarticulated plates."[12]	Pelomedusoid turtle. Named in honour of France de Lapparent de Broin.[12]
Taquetochelys[13]	T. decorata[13]	A few disarticulated plates and nearly complete skeleton.[14]	Araripemydid turtle, similar in shell size to South American Araripemys (20–30 cm). Laganemys tenerensis was synonymysed with Taquetochelys by Pérez-García, 2018.[14]
Teneremys[13]	T. lapparenti[13]	"Several relatively complete skeletons."[12]

Crocodyliformes

Crocodyliformes
Genus	Species	Material	Notes	Images
Anatosuchus[15]	A. minor[15]	"Nearly complete skull"
Araripesuchus[15]	A. wegeneri[15]	"Nearly complete skull"
Sarcosuchus[16]	S. imperator	"Partial skeletons, numerous skulls"
Stolokrosuchus	S. lapparenti

Dinosaurs

Ornithischians

Ornithischians
Genus	Species	Material	Notes	Images
Elrhazosaurus[15]	E. nigeriensis[15]	"Femora."[17]	A dryosaurid
Lurdusaurus[15]	L. arenatus[15]	"Partial skull, fragmentary postcranial skeleton."[18]
Ouranosaurus[15]	O. nigeriensis[15]	"Skull and poscrania, second skeleton."[19]

Theropods

Theropods
Genus	Species	Material	Notes	Images
Afromimus	A. tenerensis	"caudal vertebrae, chevrons and portions of the right hind limb"[20]	A putative noasaurid[21]
Cristatusaurus[22]	C. lapparenti[22]	Jaw bones and vertebral fragments.[22]	A spinosaurid potentially synonymous with Suchomimus[23]
Eocarcharia[15]	E. dinops[24]	"Partial skull and postcranial remains."[25]	Known from chimaeric remains; the holotype and skull roof material likely derive from a baryonychine spinosaurid, while the referred maxilla is from a carcharodontosaurid.[26]
Kryptops[15]	K. palaios[15]	Postcranial skeleton and partial skull.[27]	An abelisaurid
Suchomimus[15]	S. tenerensis[15]	Partial skull and associated skeleton.[28]	A baryonychine spinosaurid

Sauropods

Sauropods
Genus	Species	Material	Notes	Images
Nigersaurus	N. taqueti	Skull and skeletal remains	A rebbachisaurid.

Flora

Plants
Genus	Species	Material	Notes	Images
Paradoxopteris[29]	P. stromeri		A tree fern and member of Matoniaceae.
Protophyllocladoxylon	P.chudeaui		A conifer[29]

See also

• List of dinosaur-bearing rock formations
• Crato Formation
• Romualdo Formation