New insights into the phylogeny of glass sponges (Porifera, Hexactinellida): Monophyly of Lyssacinosida and Euplectellinae, and the phylogenetic position of Euretidae

Integrative taxonomy justifies a new genus, Nodastrella gen. nov., for North Atlantic "Rossella" species (Porifera: Hexactinellida: Rossellidae)

“…Our molecular phylogenetic analysis confirms previous reports (Dohrmann et al 2008(Dohrmann et al , 2009(Dohrmann et al , 2012 that N Atlantic hexactinellid sponges originally assigned to Rossella are more closely related to Aulosaccus and Acanthascus than to Southern Ocean Rossella spp. (Rossella s.s.).…”

“…DNA extraction, PCR amplification, Sanger sequencing, alignment with previously published hexactinellid sequences, and concatenation into a supermatrix of 18S ribosomal DNA (rDNA), partial 28S rDNA, partial mitochondrial (mt) 16S rDNA, and partial mt cytochrome oxidase subunit I (COI) were carried out as previously described (Dohrmann et al 2008(Dohrmann et al , 2009(Dohrmann et al , 2012; new sequences have been deposited in GenBank (accession-numbers HE858263-HE858272). To allow the inclusion of additional nucleotide positions whose alignment was ambiguous within the full set of available hexactinellid sequences, we restricted the ingroup to the Rossellidae and used published sequences of two Leucopsacidae specimens as the outgroup for phylogenetic analysis (see also Dohrmann et al 2011).…”

Molecular paleobiology of early-branching animals: integrating DNA and fossils elucidates the evolutionary history of hexactinellid sponges

“…Paleontologists naturally have to rely on morphological characters for taxonomic assignment, and the task for sponges is complicated by a fossil record biased toward groups with fused or articulated skeletons, leaving substantial gaps for taxa that more readily disintegrate after death (Pisera 2006). This difficult situation, however, is less severe in the Hexactinellida (glass sponges), which have recently been shown to have an evolutionary history, as elucidated by molecular sequence data, that is largely consistent with the distribution of morphological features across its traditional taxa (Dohrmann et al 2008(Dohrmann et al , 2009). However, the fossil record presently provides incomplete or ambiguous evidence regarding the origin and evolution of extant hexactinellid subtaxa (see next section).…”

“…Curiously, dictyonal skeletons are not documented from the Carboniferous, Permian, or Early Triassic (Pisera and Bodzioch 1991;Mehl and Mostler 1993;Mehl 1996), an absence that is hypothesized to be a preservational artifact (Mehl 1996;Rigby et al 2001). Although molecular data (Dohrmann et al 2008(Dohrmann et al , 2009 suggest that the ''Hexactinosida'' are paraphyletic with respect to Lyssacinosida, the majority of hexactinosidans form a highly supported clade, the Sceptrulophora (Mehl 1992;Dohrmann et al 2011), which is the sister group of the remaining hexasterophorans (Dohrmann et al 2008(Dohrmann et al , 2009). This taxon is characterized by the possession of sceptrules, a scepter-like spicule type that occurs in various forms, mostly scopules or clavules (see Dohrmann et al 2011).…”

“…This taxon is characterized by the possession of sceptrules, a scepter-like spicule type that occurs in various forms, mostly scopules or clavules (see Dohrmann et al 2011). In contrast, sceptrules are lacking in the Dactylocalycidae, which were resolved as the sister group of Lyssacinosida in molecular studies (Dohrmann et al 2009(Dohrmann et al , 2012a. Spicule fragments interpreted as sceptrules have been reported from late Cambrian and Ordovician strata (e.g., Bengtson 1986;Webby and Trotter 1993;Dong and Knoll 1996;Kozur et al 1996;Zhang and Pratt 2000).…”