Implosion of living <i>Nautilus</i> under increased pressure

In a hyperbaric chamber, a living mature specimen of Nautilus pompilius withstood a hydrostatic pressure of 8.05 MPa (80.5 kg/cm 2 ) equivalent to 785 m deep in the sea. Thereafter it was killed instantly by implosion of the shell. Before implosion, the animal reacted physiologically to increasing pressure. Therefore, the depth of 785 m can be assigned the depth limit of N. pompilius. The result bears on critical interpretations on the paleoecology and paleobiology of extinct nautiloids and ammonoids with similar shells.