Arén Formation

The Arén Formation or Arén Sandstone (Catalan: Calcàries i gresos d’Areny)^[1] is a geological formation in the Tremp-Graus Basin around Arén, Catalonia, Spain whose strata date back to the Late Cretaceous.^[2] Dinosaur remains are among the fossils that have been recovered from the formation.^[3] The formation dates to the Campanian to Maastrichtian and underlies the Tremp Group.

Arén Formation
Stratigraphic range: Campanian-Maastrichtian ~84–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Tremp-Graus Basin
Underlies	Tremp Group
Lithology
Primary	Sandstone
Other	Limestone
Location
Coordinates	42.3°N 1.6°E / 42.3; 1.6
Approximate paleocoordinates	34.0°N 1.6°E / 34.0; 1.6
Region	Lérida
Country	Spain
Type section
Named for	Arén
Arén Formation (Spain) Show map of Spain Arén Formation (Catalonia) Show map of Catalonia

Fossil content

Dinosaurs

Paleogeography of the Maastrichtian and distribution of titanosaur nesting sites

Dinosaur eggs (Megaloolithus baghensis,^[4] Sankofa pyrenaica),^[5] sauropod tracks, unnamed sauropod remains, theropod tracks, euornithopod tracks, and an unnamed iguanodont remains present in Lérida Province.

Dinosaurs of the Arén Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Ricardoestesia[6]	Indeterminate[6]	Lérida[7]
Hypselosaurus[7]	Indeterminate[7]	Lérida[7]			Later found to be unknown sauropod remains[7]
Orthomerus[7]	Indeterminate[7]	Lérida[7]
Pararhabdodon[7]	P. isonensis[7]	Lérida[7]
Rhabdodon[7]	R. priscus[7]	Lérida[7]
Titanosaurus[8]	T. indicus[8]	Lérida[7]			Later found to be indeterminate sauropod remains[7]

See also

• List of dinosaur-bearing rock formations

Paleontological sites of interest

-Les Serretes. It is a place in Vilamitjana municipality known by the finding of an important paleontological site. In this site there have found dinosaur remains that belongs to the Second biggest hadrosaur found in Spain, and the biggest of Catalonia. Also there have been found two carnívor dinosaur tooth that belongs to two new dinosaur species morphotypes.^[9][10]

• 

Picture of the dentary from les Serretes. Nowadays exposed on the Museum of Isona.