A natural ammonite fossil of the species Trachyceras multituberculatum, preserved in matrix from the Xiaowa Formation of Guizhou Province, China. This species dates to the Carnian stage of the Late Triassic, roughly 237 - 227 million years ago, and belongs to a group of coiled cephalopods related to modern squid and nautilus.
The fossil shows the characteristic coiled, ribbed shell with rows of small spiny bumps (tubercles) that give the species its name and distinctive knobby texture. Trachyceras multituberculatum is considered an index fossil - its presence helps geologists date and correlate marine rock layers from this period across the region.
Sold with matrix rock intact. Each piece is natural and one-of-a-kind.
Natural fossils may show matrix variation, surface texture, and minor imperfections from the fossilization process. These are authentic characteristics, not defects.
