Ambulacraria Ambulacraria Ambulacraria or Coelomopora is a Superphylum of invertebrate phyla which includes echinoderms and hemichordates; a member of this group is called an ambulacrarian. Phylogenetic analysis suggest the echinoderms and hemichordates separated around 533 million years ago. The Ambulacraria are part of the deuterostomes, a larger clade that also includes the Chordata, Vetulicolia and Saccorhytus. The two living clades with representative organisms are: The group Xenoturbellida (two species of worm-like animals) has previously been considered to be in this clade, but is now considered to be placed more basally among Metazoans. Fossil taxa that may lie on the stem lineage:
Branching order of bacterial phyla (Cavalier-Smith, 2002) Branching order of bacterial phyla (Cavalier-Smith, 2002) There are several models of the Branching order of bacterial phyla, one of these was proposed in 2002 and 2004 by Thomas Cavalier-Smith. In this frame of work, the branching order of the major lineage of bacteria are determined based on some morphological characters, such as cell wall structure, and not based on the molecular evidence (molecular phylogeny). Whereas modern molecular studies point towards the root of the tree of life being between a monophyletic Bacteria and Archaea+Eukarya (Neomura), in the Cavalier-Smith theory, the last common ancestor (cenansestor) was a Gram-negative diderm bacterium