I consider its loss in some Chyromyidae an apomorphy
The dramatic remodeling of the free-living larva into the sessile, tentacle-bearing adult constitutes an entoproct apomorphy
and obscures the shared characters with Mollusca, thus impeding the immediate recognition of Tetraneuralia.
Coddington's (1988) proposed test relies upon the central assumption that the apomorphic and plesiomorphic characters borne by sister taxa in current environments have equivalent selective consequences relative to their counterparts in the ancestral population in which the apomorphy
The other uses of "specialization"--evolution, adaptation, apomorphy
, or uncommon features--are synonyms of existing terms or are simply vague.
Because we do not have access to a diverse set of planktotrophs from additional taxa, we cannot yet determine whether the ADL is present and functions similarly to lytechinids in enough taxa to distinguish between an echinoid apomorphy
and that of smaller clades such as Toxopneustidae + Echinometridae.
They present an anterior branchial cluster as the only non-homoplastic morphological apomorphy
to support the Poeobius/Flota/flabelligerid clade.
The types of definitions permitted in phylogenetic nomenclature basically fall into three categories: node-based definitions, stem-based definitions, and apomorphy
The first one is a name defined by specifying a phylogenetic definition (node based, stem based, or apomorphy
based) and by designating two (or more) specifiers to refer to a particular taxon (or clade) under a particular phylogenetic hypothesis (or cladogram).
Accordingly, definitions might be of three types: node based, stem based, or apomorphy
These definitions (node based, stem based and apomorphy
based) are based solely on common descent, the idea being to "point at" a common ancestor and all of its descendants.
# 13) may be an additional apomorphy
of Cassiope, but such leaves commonly occur within Clade 1 (Fig.
It is significantly different from the plasmodial type as found in Haemodoraceae and Commelinaceae, and may be an apomorphy
for some Zingiberales.