The exact taxonomic relationships between these species remains unclear.

The challenge with this lies in the fact that a shared environment also indicates a common evolutionary history and thus a close taxonomic relationship.

They are little studied and even their taxonomic relationships with other birds are uncertain.

Further study is expected to clarify the taxonomic relationships between different species of caecilians.

Specific molecular techniques led to a closer analysis of taxonomic relationships, which is one factor that can lead to extinctions if unclear.

These eversible organs play an important role in determining taxonomic relationships.

The only close relative to the family is the stitchbird; their taxonomic relationships to other birds remain to be determined.

In mapping other taxonomic relationships, however, morphological data has been troublesome.

The taxonomic relationship of this family to associated genera is still not determined.

The taxonomic and evolutionary relationship of these two groups is poorly understood.