Cephalopods Like Fractals, TooThis is a featured page

Cephalopods Like Fractals, Too - What Lies BeneathOne often pictures fractals as consisting of pretty pictures generated by computer programs, but they are quite prevalent in nature. A notable example can be found in the fossils of ancient cephalopods, specifically nautiloids and ammonoids. Nautoloids and ammonoids are the ancient ancestors of modern squids, octopi, and the nautilus. The ancient organisms looked like modern squids and octopi with shells, some elongated and some coiled like a snail. These shells had internal chambers that the organism filled with gas for buoyancy. Each chamber is separated by a wall, or septa. The contact line between the septa and the inner shell wall is called a suture line. The structure of the suture line determines how well the organism can resist water pressure and adjust its buoyancy. The evolution of suture lines follows an increasingly fractal-like pattern from straight sutures to highly undulated sutures. In complex sutures, the dips and folds in the undulations are called lobes and saddles, respectively.Cephalopods Like Fractals, Too - What Lies Beneath

Paleontologists (Daniel et al. 1997) have found that simple sutures, as in Permian (290 – 248 million years ago) nautiloids Cephalopods Like Fractals, Too - What Lies Beneath and ammonoids, are very resistant to high pressures, but are poor for buoyancy regulation. As a result, such organisms moved slowly. Conversely, the more complex suture lines of Cretaceous (144 – 66 million years ago) organisms have less pressure resistance along with excellent buoyancy control. These findings indicate that the evolution of Cephalopods proceeded from high-pressure deep water to low-pressure shallow water over millions of years, with increasing complexity in suture lines to compensate. Daniel, T.L., B.S. Helmuth, W.B. Saunders, and P.D. Ward. 1997. Septal complexity in ammonoid cephalopods increased mechanical risk and limited depth. Paleobiology 23(4):470-481. Cephalopods Like Fractals, Too - What Lies Beneath Cephalopods Like Fractals, Too - What Lies Beneath


No user avatar
lamontequinn 		Latest page update: made by lamontequinn , Apr 25 2008, 3:08 PM EDT (about this update About This Update lamontequinn Edited by lamontequinn


view changes
- complete history)
Keyword tags: None
More Info: links to this page

Threads for this page

There are no threads for this page.  Be the first to start a new thread.