(A) Cumulative growth distances in cm for each specimen against time, showing the difference between the Paris and Hampshire Basins. (B) Growth Rate in mm per day for each specimen against time, showing the similarity in timing of growth cessations and difference in maximum growth rate between the Paris and Hampshire Basins. Idealized growth rates, estimating the average growth rate per species, per basin shown as a colored (blue and green for the Paris and Hampshire Basins, respectively) dotted line.