Metazoa comprises 35–40 phyla that include some 1.3 million described species.
Phylogenetic analyses of metazoan interrelationships have progressed in the past two …

DNA sequence analysis dictates new interpretation of phylogenic trees. Taxa that were once
thought to represent successive grades of complexity at the base of the metazoan tree are …

How, why, and when consciousness evolved remain hotly debated topics. Addressing these
issues requires considering the distribution of consciousness across the animal …

The arthropods constitute the most diverse animal group, but, despite their rich fossil record
and a century of study, their phylogenetic relationships remain unclear1. Taxa previously …

The Class Bdelloidea of the Phylum Rotifera is the largest metazoan taxon in which males,
hermaphrodites, and meiosis are unknown. We conducted a molecular genetic test of this …

Insight into the origin and early evolution of the animal phyla requires an understanding of
how animal groups are related to one another. Thus, we set out to explore animal phylogeny …

Cladistic analysis of traditional (ie morphological, developmental, ultrastructural) and
molecular (18S rDNA) data sets (276+ 501 informative characters) provides a hypothesis …

The Cambrian explosion is named for the geologically sudden appearance of numerous
metazoan body plans (many of living phyla) between about 530 and 520 million years ago …

Triploblastic relationships were examined in the light of molecular and morphological
evidence. Representatives for all triploblastic “phyla”(except Loricifera) were represented by …

We used a data matrix of 65 morphological characters from 25 ingroup and 6 outgroup taxa,
and an alignment comprising complete 18S rDNA sequences from 82 species of parasitic …