The relationships at the root of the animal tree have proven difficult to resolve, with the current debate focusing on whether sponges (phylum Porifera) or comb jellies (phylum Ctenophora) are the sister group of all other animals [1-5]. The choice of evolutionary models seems to be at the core of the problem because Porifera tends to emerge as the sister group of all other animals ("Porifera-s...

One new species of the genus Ctenophora Meigen, 1803, C. fumosa Men, sp. nov. (southern China: Anhui) is described and illustrated. A key to known species along with a checklist of known species of the genus Ctenophora are provided. The type specimens of the new species are deposited in the animal specimen room, School of Life Science, Anqing Normal University, Anqing, Anhui Province, China. 

Understanding how complex traits, such as epithelia, nervous systems, muscles, or guts, originated depends on a well-supported hypothesis about the phylogenetic relationships among major animal lineages. Traditionally, sponges (Porifera) have been interpreted as the sister group to the remaining animals, a hypothesis consistent with the conventional view that the last common animal ancestor was...

Six alternative hypotheses for the phylogenetic origin of Bilateria are evaluated by using complete 18S rRNA gene sequences for 52 taxa. These data suggest that there is little support for three of these hypotheses. Bilateria is not likely to be the sister group of Radiata or Ctenophora, nor is it likely that Bilateria gave rise to Cnidaria or Ctenophora. Instead, these data reveal a close rela...

The role of the cellular microenvironment in enabling metazoan tissue genesis remains obscure. Ctenophora has recently emerged as one of the earliest-branching extant animal phyla, providing a unique opportunity to explore the evolutionary role of the cellular microenvironment in tissue genesis. Here, we characterized the extracellular matrix (ECM), with a focus on collagen IV and its variant, ...

The phylogenetic relationships of deep metazoans, specifically in the phylum Ctenophora, are not totally understood. Previous studies have been developed on this subject, mostly based on morphology and single gene analyses (rRNA sequences). Several loci (protein coding and ribosomal RNA) from taxa belonging to this phylum are currently available on public databases (e.g. GenBank). Here we revis...

In their letter, Halanych et al. (1) criticize our recent assertion (2) that the phylogenetic placement of ctenophores as the sister group to all other animals (the Ctenophora-sister hypothesis) in three previous studies (3–5) was an artifact caused by undetected systematic error. Halanych et al. (1) claim we used no “objective approaches” to identify sources of systematic error. In fact, we us...

A new genus, Dendrogramma, with two new species of multicellular, non-bilaterian, mesogleal animals with some bilateral aspects, D. enigmatica and D. discoides, are described from the south-east Australian bathyal (400 and 1000 metres depth). A new family, Dendrogrammatidae, is established for Dendrogramma. These mushroom-shaped organisms cannot be referred to either of the two phyla Ctenophora...