Gaudrycerataceae

Gaudrycerataceae is a family of extinct ammonites, a group of cephalopods closely related to modern-day nautiluses. These ammonites are characterized by their generally small to medium-sized, involute to semi-involute shells, meaning the inner whorls are largely or entirely covered by the outer whorls. Their sutures, the lines where the internal walls of the shell meet the external shell, are typically simple, often trifid or bifid with broad saddles and narrow lobes. The shell ornamentation is usually smooth, with faint growth lines being the most prominent feature. Some species may exhibit very fine ribbing or lirae.

Fossils of Gaudrycerataceae are found in marine sedimentary rocks dating from the Late Cretaceous period. They are known from various locations worldwide, indicating a widespread distribution during their time. This family is important for biostratigraphy, helping paleontologists date rock layers. The genus Gaudryceras is the type genus for this family and is recognized by its smooth, involute shell and complex suture patterns. Other notable genera include Eogaudryceras and Ductoroceras. The precise ecological role of Gaudrycerataceae is not fully understood, but like other ammonites, they were likely nektonic predators or scavengers inhabiting open marine environments. Their extinction at the end of the Cretaceous period coincided with the Cretaceous-Paleogene extinction event.