settus

Settus is a genus of extinct ammonites, a type of marine cephalopod, that lived during the Early Jurassic period. The fossils of Settus have been found in various parts of the world, including Europe, North America, and Russia. These fossils are characterized by their distinctive shell morphology, which includes coiled ribs and a distinctive "shoulder" or "knee" at the juncture of the body chamber and the last whitened coil.

The shell of Settus was narrow and elongated, typically measuring up to 30 centimeters in length. The sutures, or the lines where the shell's individual components meet, were relatively complex and often featured a distinctive fan-shaped pattern. This suggests that the Settus genus was a relatively advanced form of ammonite compared to its contemporaries.

The species of Settus were adapted to life in warm, subtropical waters, which is consistent with the evidence of the Early Jurassic paleoclimate. Fossil evidence suggests that Settus species fed on small marine animals, such as plankton and invertebrates, using their radial rows of suckers to trap their prey.

Settus species went extinct at the end of the Early Jurassic period, along with a number of other co-occurring ammonite and bivalve species. This extinction event is thought to have been triggered by significant environmental changes, possibly related to climate disruption or sea-level changes, although the exact causes are still debated among paleontologists.