A
typical HISTORICAL phylogenetic tree of invertebrate phyla:
Absolute horizontal distance on
the above diagram does not imply relative evolutionary time since divergences.
Instead, the diagram above should only be interpreted as order (sequence)
of divergence within a particular taxonomic lineage.
Click here
to compare with a more modern (simplified) version
Some major difference shown above compared
to the more modern version include:
-
A generally more 'bushy' tree in the modern
version than in the above historical phylogeny
-
Nematodes are more closely related to arthropods
than in the above historical phylogeny
-
Arthropods are more distantly related to annelids
and molluscs than in the above historical phylogeny
-
Bryozoans and other lophophorates are more closely
related to annelids and molluscs than in the above historical phylogeny
-
Platyhelminthes are more closely related to
annelids and molluscs than in the above historical phylogeny
Some other differences (not shown in the tree
above) involving more minor phyla
-
lophophorate phyla have been considered as intermediates,
or as deuterostomes, or as unrelated groups with some being protostomes
and others deuterostomes
-
Onychophorans historically have been considered
by some to be closely related to annelids while others have considered
them more closely related to arthropods (as in the modern version).
-
Tardigrades historically have been considered
by some to be closely related to rotifers while others have considered
them more closely related to arthropods (as in the modern version).
-
Pogonophora were often considered a phylum within
the dueterostomes, but more recently have been included as a sub-taxon
within the protostome phylum Annelida.
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with the more modern full version with all animal phyla
