Sentence examples for of shell characters from inspiring English sources

Covariation of shell characters is well-known for ammonoids [ 166].

The species and subspecies determination was based on a combination of shell characters (expression of aperture folds and shell form) and the geographic distributions reported in literature [ 2, 21].

Vectors of shell characters (length and direction compared to the PC axes) revealed that variation on PC1 is mainly associated with Dmx, WSC, NLb/OLb, FCI and UWI, PC2 with WER and IZR, and PC3 with WSC.

Recent reports of Tricula from Nepal (e.g., Tricula godawariensis Nesemann & Sharma 2007) [ 41] are simlarly data deficient, with descriptions of new taxa based on shell characters only – as noted by Davis [ 42], one cannot distinguish these taxa on the basis of shell and radula characters alone.

Hence, although adaptation and covariation largely shape the morphological evolution of ammonoids, the still divergent evolution of several shell characters of both lineages in our case of parallel evolution imply that the unique histories of organisms still play a large role in shaping the evolutionary trajectory of clades [ 2].

The descriptions in the 2012 study appear to be based on shell character states and so the possibility that these snails were derived from early Pliocene Chinese Gammatricula in the nearby provinces of Yunnan and Guangxi cannot be excluded.

Both ammonoid lineages display empirical morphological evolutionary trends of some shell characters.

A delimitation of the two taxa is problematic, because the shell characters are highly variable and do not allow to clearly distinguish the two species (see pictures in [ 16] and [ 21]).

The PCA plots indicate which shell characters contribute to the morphological evolution of Devonian ammonoids by creating high variation.

However, this expectancy does not hold on a continental scale; morphs belonging to clades 1 and 2 of our phylogeny cannot be readily distinguished from one another using shell characters.

Only few individuals show intermediate shell characters indicating possible hybridization.