- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Elongated belemnites illustrated by Albert and Arnold Heim were not deformed as brittle bodies, because the guards have undergone recrystallization. A tentative hypothesis is put forward to integrate the mechanical and chemical processes in the belemnites. During progressive extension of the belemnites carbonate material has diffused from highly stressed fragments of the guards into 'low-stress' spaces between the fragments.