Huge Ammonite Argonauticeras besairei from early Cretaceous of Madagascar. This big specimen show surface view of the conch with the suture line slightly shining through the shell wall. Suture lines are normally visible only on the external part of the shell. In this case the amazing preservation of the shell and an expert preparation made possible to observe the fractal structure of the hidden septum. A painstaking preparation, many hours to remove all the matrix with extreme care as the shell is very fragile, make it possible, make visible all the hidden details of the internal structure. An amazing example of the frilled septal lobe margin as demonstration for how complex( fractals geometric sequence) ammonite septa can be. Fantastic mineralization, original internal shell preserved. Ammonite is 15 cm diameter, 7 cm thick. A "must piece" for all the Ammonite Lovers.