Data from: Morphometric analysis of inter- and intraspecific variation in the Cambrian helcionelloid mollusc Mackinnonia ...

• Main Authors: Jackson, Illiam S.C., Claybourn, Thomas M.
• Format: Dataset
• Language: English
• Published: Dryad 2019
• Subjects: Helcionelloida; species concept; incipient species; Elliptical Fourier Analysis; Early Cambrian; Davidonia; Cambrian Series 2; Ajax; Shackleton; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.5061/dryad.5b7n3; https://datadryad.org/stash/dataset/doi:10.5061/dryad.5b7n3

Phylogenetic relationships within the helcionelloids have been difficult to establish. One of the reasons for this is that qualitative approaches to investigating morphological variation in this group have struggled to identify clear patterns. An alternative method of identifying these patterns is to study these organisms quantitatively. Here this approach is exemplified by employing morphometric methods to investigate patterns of subtle morphological variation in two species of Mackinnonia Runnegar in Bengtson et al from Cambrian Series 2, Stages 3–4. Specifically, a combination of elliptical Fourier and multivariate analyses were conducted to study intra- and interspecific variation in protoconch form as well as variation in ontogenetic trajectory of the teleoconch of two species of Mackinnonia. The material used consists of two assemblages of Mackinnonia rostrata (Zhou & Xiao), from the Shackleton Limestone of Antarctica and Ajax Limestone of Australia, and an assemblage of Mackinnonia taconica ... : Ontogeny dataset.jmp file (type used in analysis in JMP software) including EFA residuals and PCA results for all data including for each rib and protoconchs of all data.Ontogeny dataset.csv file including EFA residuals and PCA results for all data including for each rib and protoconchs of all data.Protoconch dataset.jmp file (type used in analysis in JMP software) including EFA residuals and PCA results for protoconch data onlyProtoconch dataset.csv file including EFA residuals and PCA results for protoconch data only ...