Hi friends, can you help me with this? I went to Al Hasi city, Sulaiy formation ( Berriasian) , Cretaceous , to the north of Riyadh and found this strange fossils. It was a surface find; it is 20 cm long, 18 cm wide, and 3-4 cm thick. The outer face is rough and in layers , the inner surface is semicircular and smooth , similar fossils are everywhere in the same area in varies sizes . So what could it be?