In recent years, scientists have made remarkable progress reconstructing the animal
phylogeny. There is broad agreement regarding many deep animal relationships, including …

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

The position of Xenacoelomorpha in the tree of life remains a major unresolved question in
the study of deep animal relationships. Xenacoelomorpha, comprising Acoela …

Meiobenthology is the science of the tiny animals that live in huge numbers in all aquatic
sediments. This fully revised and enlarged second edition emphasizes new discoveries and …

A clear picture of animal relationships is a prerequisite to understand how the morphological
and ecological diversity of animals evolved over time. Among others, the placement of the …

Systematics has developed rapidly during the past two decades. A multitude of new
methods and contributions from a diversity of biological fields including molecular genetics …

SUMMARY A review of the old and new literature on animal morphology/embryology and
molecular studies has led me to the following scenario for the early evolution of the …

How complex body plans evolved in animals such as fruit flies and vertebrates, as compared
to the relatively simple jellyfish and sponges, is not known, given the similarity of …

Ten phosphatized specimens of a small (< 180 micrometers) animal displaying clear
bilaterian features have been recovered from the Doushantuo Formation, China, dating from …

The central nervous system (CNS) in different animals develops under the control of genes
that are often conserved both structurally and functionally. The question of whether such …