Multiple trackways from the Cenomanian Djoua series, in In Amenas region (southeastern Algeria), represent the first ichnological evidence of gregarious behavior in Cretaceous sauropods from Africa

For the first time, a complete study of sauropod trackways has been carried out in the lower part of the Djoua series in the In Amenas region (southeastern Algeria). Several locomotion tracks have been discovered in this area. In the present work, we report the discovery of sauropod tracks exposed on a bedding surface of the Lower Formation attributed to the early Cenomanian that we assign to cf. Brontopodus isp. The tracks are located in two different areas approximately 2 km apart and are oriented N00° and N330° at the first and second sites, respectively. These tracks were formed when dinosaurs crossed an emergent or lightly submerged river plain. At the second site, trackways show several tracks generated by sauropods. They are sub-parallel in orientation and provide the first ichnological evidence of gregarious behavior in Cretaceous sauropods in Africa