Neubauer, Thomas A; Harzhauser, Mathias; Kroh, A (2013): Phenotypic evolution in a fossil gastropod species lineage: evidence for adaptive radiation? PANGAEA, https://doi.org/10.1594/PANGAEA.803659, Supplement to: Neubauer, TA et al. (2013): Phenotypic evolution in a fossil gastropod species lineage: evidence for adaptive radiation? Palaeogeography, Palaeoclimatology, Palaeoecology, 370, 117-126, https://doi.org/10.1016/j.palaeo.2012.11.025
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Detecting speciation in the fossil record is a particularly challenging matter. Palaeontologists are usually confronted with poor preservation and limited knowledge on the palaeoenvironment. Even in the contrary case of adequate preservation and information, the linkage of pattern to process is often obscured by insufficient temporal resolution. Consequently, reliable documentations of speciation in fossils with discussions on underlying mechanisms are rare. Here we present a well-resolved pattern of morphological evolution in a fossil species lineage of the gastropod Melanopsis in the long-lived Lake Pannon. These developments are related to environmental changes, documented by isotope and stratigraphical data. After a long period of stasis, the ancestral species experiences a phenotypic change expressed as shift and expansion of the morphospace. The appearance of several new phenotypes along with changes in the environment is interpreted as adaptive radiation. Lake-level high stands affect distribution and availability of habitats and, as a result of varied functional demands on shell geometry, the distribution of phenotypes. The on-going divergence of the morphospace into two branches argues for increasing reproductive isolation, consistent with the model of ecological speciation. In the latest phase, however, progressively unstable conditions restrict availability of niches, allowing survival of one branch only.
Median Latitude: 47.856093 * Median Longitude: 16.421120 * South-bound Latitude: 47.181667 * West-bound Longitude: 16.164722 * North-bound Latitude: 48.493333 * East-bound Longitude: 16.658889
The dataset stored here includes the measurements of the gastropod shells, the data used for the boxplots, the 448 tps-files used for the Fast Fourier Analysis, and the resulting matrix of Fourier coefficients. The tps-files generated with the program TpsDig2 contain pairwise x,y-coordinates, each file describing one outline of a digitised gastropod shell.