6533b7d8fe1ef96bd126a138

RESEARCH PRODUCT

Mode and Rate of Growth in Ammonoids

Susan M. KlofakJean GuexNeil H. LandmanHugo Bucher

subject

Whorl (mollusc)Evolutionary biologyOntogenyMode (statistics)Generalized GrowthSoft bodyGrowth curve (biology)BiologyRate of growth

description

In this chapter we discuss the mode and rate of growth in ammonoids, focusing primarily on postembryonic growth. We first discuss the general mode of growth and then describe the ontogenetic sequence of growth stages. These stages are recognized on the basis of changes in morphology. For example, a graph of the increase in size of whorl width versus shell diameter in an individual reveals changes through ontogeny that pinpoint the end of one growth stage and the beginning of another. We next discuss the overall rate of growth through ontogeny and establish a generalized growth curve. In this discussion, we refer to other cephalopods whose rate of growth is known. Fluctuations in the rate of growth that are superimposed on this growth curve are indicated in ammonoids by the presence of such shell features as varices and constrictions.

yearjournalcountryeditionlanguage
1996-01-01
https://doi.org/10.1007/978-1-4757-9153-2_12