A typical and largely followed morphological based taxonomy is that of Groves (1993)[ 35] with two families: 1. Callitrichidae, including the genera Callimico, Callithrix, Leontopithecus, Saguinus, and 2. Cebidae: including genera Alouatta, Aotus, Ateles, Brachyteles, Lagothrix, Callicebus, Cebus, Saimiri, Cacajao, Chiropotes, and Pithecia.
Alpha taxonomy in spiders is typically approached from a morphological perspective that is based primarily on differences in genitalic structures [35].
Although the biological species concept (BSC; groups of actually or potentially inter-breeding natural populations, which are reproductively isolated from other such groups) [19], is accepted by most zoologists, species descriptions and names are most often based on morphological difference that should be shown to be non-overlapping between species.
Scotti [ 5] presented the automatic morphological method that is based on the morphological analysis of WBCs.
Finally, glomerulonephritides are still classified based on morphological criteria that date back to the seventies.
Several earlier hypotheses based on morphological features that claim to diagnose certain groups also remain untested across larger groups.
As a consequence, species boundaries are based on morphological characters that are not expressed under all conditions.
For all species present in the streams, we constructed a trait matrix based on morphological features that are known to be of ecological relevance (Table 1).
To ensure consistency in identifications among localities, each coral was sampled by at least two authors, based on morphological features that can be recognized in the field.
In order to place the newly described fossil in a phylogenetic context, we assembled a morphological matrix that is based on the phylogenetic assessment of Miller [ 30], including all extant and fossil members of the extant genera plus those fossil rhizome species that agree in all anatomical features with those of modern genera [see Additional file 1; ESA].
