I agree with Dieter Korn, it looks like some of the measurments are in the wrong columns. Whorl Height can surely not exceed Diameter.

OOOOOOOOOOOOOH

I`m sorry.

I agree whit you. It is Typographical error.

Please download the correct meassurements.

Tayyeb,

I hope the measurments and calculated parameters shown in this source can hlp you along:

An example of  graphic explainations can be found on the following google books excerpt of the book

Neil H. Landman, Richard Arnold Davis, Royal H. Mapes 2007, Cephalopods Present and Past: New Insights and Fresh Perspectives: New Insights and Fresh Perspectives. Springer Science & Business Media, 500 pages

http://books.google.de/books?id=Q19AwHOqOZ0C&pg=PA63&lpg=PA63&dq=whorl+expansion&source=bl&ots=LDnpJ7mnGn&sig=7KNAcvRIouQDfccCjZ1k8PIDUtM&hl=de&sa=X&ei=LFjBU9aeLebI0QW12oDwAQ&ved=0CDUQ6AEwAg#v=onepage&q=whorl%20expansion&f=false

Very very thanks dear Jens

Hi, I usually list Diameter (D) if possible at aperture, end of phragmocone and somewhere between. At these same three points Whorl height (Wh), Whorl breadth (Wb) and Umbilical diameter (Ud) and express these as percentages of Diameter. Bivariate graphs of these against D, a line for each specimen, gives a clear indication of variability with growth and in the population. In addition count the number of primary and secondary ribs, most practical usually per half whorl. More difficult to measure are angles - curvature and projection of ribs,angle between whorl sides and venter and shape and width of venter. Hope this helps

Dear Nicol Morton, Very very thanks. 

good.good

Dear Tayyeb,

Keep in mind that in coiled ammonoids, diameter is directly linked with whorl height as a consequence of coiling, so be very careful with the correlations you will obtain between D and Wh. Check articles by Richard Reyment.

In my opinion, even before starting your measurements, the first question is what do you want to quantify or study ? There are already plenty of statistic studies on ammonites, so what more do you want to aim at ?

Indeed so. Check out my algebraic studies of ammonites, male and female in www.richardreyment.com.