Molecular phylogenetic evaluation of classification and scenarios of character evolution in calcareous sponges (Porifera, Class Calcarea)

Calcarea build calcite spicules and exhibit varied aquiferous-system organization; Voigt and colleagues illustrate asconoid, syconoid, sylleibid and leuconoid examples, rather than one body plan shared unchanged by every species.

Expanded ribosomal-gene sampling rejects several traditional internal Calcarea groups and tests character evolution; the recovered trees are sample-dependent and do not date the class.

Calcarea has no supported scalar temporal range in the cited evidence: the sampled extant phylogeny does not establish a 535 Ma fossil occurrence or crown boundary, so the former 535–0 Ma display is withheld.