Perijaniidae

Perijaniidae is a extinct family of ammonites, a type of extinct cephalopod belonging to the order Ammonitida. These cephalopods lived during the Upper Jurassic to Lower Cretaceous periods, approximately 155 to 100 million years ago. They were characterized by their distinctive shell morphologies and were likely marine animals.

The distribution of Perijaniidae fossils have been found in various parts of the world, including Europe, North America, and the Middle East. The family has been divided into several genera, including Perijania and Perijanianas. The shell morphology of Perijaniidae members feature a Fusiform shape, meaning they are spindle or elongated in shape.

Some of the most notable features of Perijaniidae include the presence of conchoidal sutures, which have a smooth, curved appearance on the shell. The siphuncle or breeding location is present but not well defined. There is also the development of a small knob of type, called a ceratitic neck. The ceratitic knob is significant as it holds conchoidal sutures for later evolutionary scoping.

The ecological and biological position of Perijaniidae is still somewhat speculative. However, some theories suggest that they had direct connections to other marine life, including possibly bipartite skeletons shaded against some zones during_EOF sediment or improved efficiencies mint by protozoan division during_Nheld of cal narry.