ammonitisch

Ammonitisch is a German adjective that denotes a relationship to ammonites (Ammonit), an extinct group of marine cephalopods. In geological and paleontological usage, the term describes fossils, rocks, or features that are related to ammonites or resemble them, rather than a strict taxonomic category.

The term is most often encountered in two contexts. First, it refers to ammonite fossils themselves or to parts of their shells, such as the characteristic planispiral coiling and the varied suture patterns between septa. In particular, ammonitic sutures—intricate and highly segmented lines—are a key morphological feature associated with certain ammonite groups and time intervals. Second, ammonitisch is used in stratigraphy and lithology to describe rock types or beds that are richly fossiliferous with ammonites, or that commonly preserve ammonite assemblages. For example, rock units known for abundant ammonite fossils in the Jurassic or Cretaceous may be described as ammonitisch.

Geographically and historically, the term appears in German-language paleontological and geological literature and can appear in discussions of specific formations, such as ammonite-rich limestones. It is important to note that ammonitisch is descriptive rather than taxonomic; it does not designate a distinct lineage or species, but rather the ammonite-related character of fossils or rocks.

See also: ammonite, ammonite sutures, biostratigraphy, ammonite-rich formations.