The top of the Serravallian (the base of the Tortonian stage) is at the last common appearance of calcareous nannoplanktons Discoaster kugleri and planktonic foram Globigerinoides subquadratus.
The fossil remains of Titanocetus was discovered within some marine deposits dating back to the Serravallian (middle Miocene) and belonging to the "Fumaiolo Formation" (Republic of San Marino).