About 183 million years ago, the Volga region and most of Eastern Europe were buried under the warm sea waters inhabited with various extraordinary live organisms. Many have not survived to this day but we can imagine what they were by observing their petrified remains. The Volga riverbed in the Kashpir area provides access to Jurassic deposits containing fossils of ancient species. Researchers believe the petrified ammonite shells to be the most essential of those. Due to the rapid evolution and widespread distribution of ammonites, deposits can be attributed to different time periods.

They are named after the Egyptian god Ammon (Amun). He was typically depicted wearing rams' horns which resemble ammonite shells. In 1789, French zoologist Jean Bruguier (bru-ghi-´ey) ‘legalized’ the name of the mollusk by introducing the Latin term ‘ammonites.’

Most ammonites had a tightly coiled shell. However, some of them were the so-called heteromorphs. They had uncoiled, hook-shaped or straight shells. So far, no prints of ammonites' interior have been discovered. Nevertheless, scientists believe ammonites had soft body tissue with 10 tentacles and well-developed eyes.

Their shell was divided into chambers (septa). The front one, which was the biggest, had the body itself. The buoyancy of the shell was regulated with a siphuncle. The aperture was closed with aptychus (´ap-ti-chus), calcite or horny hatch. Ammonites only inhabited in normal-salinity seas without ever entering freshwaters. The last representatives of this group disappeared from the face of the Earth at the end of the Mesozoic Era.

Two specific ammonite genera are of interest for residents and visitors of the city of Syzran, as well as for geologists, since they were named after the settlements in the Samara region. One of them, a large ammonite (up to 60 cm in diameter), is Simbirskites. The name dates back to the late 19th century and refers to Simbirsk, the former name of the city of Ulyanovsk. Speetoniceras versicolor, also belonging to the genus, is exhibited in the museum. The second genus is KashpUrites. Merely 3–6 cm in diameter, it was not particularly remarkable. However, its name is derived from Kashpir, the old settlement near Syzran where cropped out Mesozoic rocks over 180 million years of age can be found and where the first records of the genus were made.