SINCLAIR STAMMERS / SCIENCE PHOTO LIBRARY. SINCLAIR STAMMERS / SCIENCE PHOTO LIBRARY.
Fossilized nautilus shell, Nautilus striatus, from the lower Jurassic period (195 to 172 m.y.), found in Lyme Regis. Nautilus, a Cephalopod, is represented today by one family found in the Indo-Pacific region. The shell is spirally coiled & divided by transverse septa (covered with calcite crystals here) into numerous gas-filled chambers, which maintain the animal's buoyancy. The living animal occupies the most recently formed chamber. The enclosure of gas is through the siphuncle or shelly tube (visible at centre), which connects the gas-filled chambers with the animal. In newly formed chambers water is pumped out by the siphuncle. Locomotion is by water jets.
Model release not required. Property release not required.