AtlantaRoger R. Seapy This tree diagram shows the relationships
between several groups of organisms. The root of the current
tree connects the organisms featured in this tree to their
containing group and the rest of the Tree of Life. The basal
branching point in the tree represents the ancestor of the other
groups in the tree. This ancestor diversified over time into
several descendent subgroups, which are represented as internal
nodes and terminal taxa to the right. You can click on the root
to travel down the Tree of Life all the way to the root of all
Life, and you can click on the names of descendent subgroups to
travel up the Tree of Life all the way to individual
species.close box Atlanta is the type genus of the Atlantidae,
containing all but two of the species in the family (the other
two genera, Protatlanta and Oxygyrus, are monospecific). The
shell and keel are calcareous (composed of aragonite). The
larval shell is retained following metamorphosis, becoming the
spire in the adult shell. All specie