Hoplitoides ammonite 220mm taken from the longest width measurement.The Hoplitoides (KOENEN 1897), has an evolute, discus shaped shell type, with strong narrow or thinning keel form, with a small umbilicus (central inner whorls). The outer shell has been removed and the whole has undergone precise and exacting preparation with an acid conservation enabling a fine semi matt surface. This process has revealed the delightful colouration within the limestone shell, also given the whole an organic appeal. Each chamber is picked out by the chalcedony quartz minerals that have been absorbed into the body cavities via per-mineralisation, when silts or mud's filled the empty shell eons ago, of the now extinct marine mollusc. The cause of the fossilisation action developing over millions of years.
Fossil shells of the ammonoids have fascinated scholars for many centuries. Part of the Ammonoidea subclass, the class of Cephalopoda, related to our extant octopi. This is fossil remains of the internal shell of the marine animal, which created the outer shell or exoskeleton from chitin, a substance of a long-chain polymer of an N-acetylglucosamine (glucosamine and acetic acid), a derivative of glucose, an important building block mineral for the exoskeletons of many cephalopods, cephalopods are from the mollusca family, nautili, lobsters, crabs and shrimps.