Sansan paleontological site

The paleontological site is located inside the commune of Sansan, on the Campané hill at 238 m (781 ft) above sea level, in the Gers department, 16 km (9.9 mi) south of Auch. The hill and its surroundings were historically called "Camp de las hossos".[4]

The deposits were excavated regularly from 1834 to 1999. Francis Duranthon from the Toulouse Museum and Pascal Tassy from the Paris Museum were the last researchers to have worked on Sansan, specifically on the southern flank.

Outcrops were backfilled, vegetation grew back and a paleontological trail[5] was created in 2018 by the Communauté de communes du Val de Gers. Today, research have stopped but the site is open for public access.[6] A 2.5 km (1.6 mi) trail, marked by interpretive panels, helps to teach how Edouard Lartet discovered the site and how his discovery revolutionized the scientific theories of the time and exposed the richness of its Miocene fauna and flora.

• The paleontological trail
• 
  Panel of Édouard Lartet at the beginning of the trail
• 
  The trail
• 
  Interpretive panel on the trail
• 
  Archaeobelodon skeleton near the Ferme du Campané
• 
  Amphycion skeleton

The site of Sansan gave 85 mammal species from 9 orders, 30 families and 75 genera, being one of the richest Miocene sites in Europe. One of the most important discoveries on the site was the description by Edouard Lartet in 1837 of Pliopithecus, a catarrhini monkey, which was a keystone in the reject of creationism by scientists and the advance towards the evolution theory.

The first fossil was discovered in 1834 by the shepherd Joseph Débats, who lived on the hilltop. It was a proboscidean molar. He told the Gers lawyer Edouard Lartet, who explored the site. The Sansan mastodont, Archaeobelodon, was entirely reconstructed in 1851 by Laurillard, a first in Europe.

Edouard Lartet describes in 1834 a large carnivore, which he named Amphicyon major.

The first fossils of the chalicothere species Anisodon grande were also recovered in Sansan.

The following table shows all 85 species of mammals found in Sansan.

Proboscidea

Genus	Species	Family	Images
Gomphotherium	G. angustidens	Gomphotheriidae
Archaeobelodon	A. filholi	Gomphotheriidae
Deinotherium	D. giganteum	Deinotheriidae
Prodeinotherium	P. bavaricum	Deinotheriidae
Zygolophodon	Z. turicensis	Mammutidae

Perissodactyla

Genus	Species	Family	Images
Anchitherium	A. aurelianense hippoides	Equidae
Anisodon	A. grande	Chalicotheriidae
Aceratherium	A. (Alicornops) simorrense	Rhinocerotidae
Brachypotherium	B. brachypus	Rhinocerotidae
Lartetotherium	L. sansaniense	Rhinocerotidae

Artiodactyla

Genus	Species	Family	Images
Micromeryx	M. flourentianus	Moschidae
Dicrocerus	D. elegans	Cervidae
Heteroprox	H. larteti	Cervidae
Eotragus	E. clavatus	Bovidae
cf. Ampelomeryx	cf. A. magnus	Palaeomerycidae
Choeromorus	C. mammillatus	Palaeomerycidae
Dorcatherium	D. crassum	Tragulidae
Listriodon	L. splendens	Suidae
Conohyus	C. simorrensis	Suidae

Rodentia

Genus	Species	Family	Images
Euroxenomys	E. minutus	Castoridae
Steneofiber	S. sp. aff. S. eseri	Castoridae
Eumyarion	E. medius	Cricetidae
Cricetodon	C. sansaniensis	Cricetidae
Democricetodon	D. gaillardi	Cricetidae
	D. sp. aff. D. gracilis	Cricetidae
Megacricetodon	M. gersii
	M. minor	Cricetidae
Keramidomys	K. carpathicus octaviae
	K. mohleri	Eomyidae
Albanensia	A. sansaniensis	Sciuridae
Blackia	B. miocaenica	Sciuridae
Spermophilinus	S. bredai	Sciuridae
Heteroxerus	H. grivensis	Sciuridae
Tamias	T. minutus	Sciuridae
Palaeosciurus	P. sp. cf. P. minutus	Sciuridae
Sciuridae gen. indet.		Sciuridae

Lagomorpha

Genus	Species	Family	Images
Prolagus	P. oeningensis sansaniensis	Ochotonidae
Lagopsis	L. sp. aff. L. verus	Ochotonidae
Leporidae indet.

Primates

Genus	Species	Family	Images
Pliopithecus	P. antiquus	Pliopithecidae
Plesiopliopithecus	P. auscitanensis	Pliopithecidae

Carnivora

Genus	Species	Family	Images
Sivanasua	D. sp. indet.	Lophocyonidae
Amphicyon	A. major	Amphicyonidae
Pseudocyon	P. sansaniensis	Amphicyonidae
Alopecocyon	A. goeriachensis	Ailuridae
Hemicyon	H. sansaniensis	Ursidae
Ursidae gen. indet.	sp. indet.	Ursidae
Plithocyon	P. armagnacensis	Ursidae
Pseudaelurus	P. quadridentatus	Felidae
Styriofelis	S. lorteti	Felidae
	S. turnauensis	Felidae
Sansanosmilus	S. palmidens	Nimravidae
Ischyrictis	I. zibethoides	Mustelidae
Martes	M. sansaniensis	Mustelidae
Proputorius	P. sansaniensis	Mustelidae
Mustelidae indet.		Mustelidae
Taxodon	T. sansaniensis	Mustelidae
Lartetictis	L. dubia	Mustelidae
Semigenetta	S. sansaniensis	Viverridae
Viverrictis	V. modica	Viverridae
Leptoplesictis	L. atarus	Herpestidae
Carnivora indet.	sp. indet.	Carnivora
Carnivora indet.	sp. indet.	Carnivora

• DREAL Occitanie (ed.). "Le paléosite classé de Sansan (32) valorisé".
• Museum national d'Histoire naturelle (ed.). "Le paléosite de Sansan".
• " Le paléosite de Sansan", Communauté de Communes Val de Gers