Annulonemertes (phylum Nemertea): when segments do not count
2007
The Phylogenetic Position of Annulonemertes minusculus
Sample size: 1
publication
Evidence: moderate
Author Information
Author(s): Per Sundberg, Malin Strand
Primary Institution: Göteborg University
Hypothesis
Does the metameric segmentation in Annulonemertes have any phylogenetic significance at all?
Conclusion
The external constrictions in Annulonemertes minusculus are not phylogenetically informative and are likely convergent structures.
Supporting Evidence
- The phylogenetic analysis places Annulonemertes among the hoplonemerteans.
- The segmentation in Annulonemertes is shown to be an apomorphic character.
- The study suggests that the body constrictions may be adaptations for life in sand.
Takeaway
This study looked at a worm called Annulonemertes and found that its body segments don't really help us understand how it is related to other animals.
Methodology
The study involved sequencing the 18S rDNA gene from a specimen of Annulonemertes and conducting a phylogenetic analysis.
Limitations
The study could not include other related genera in the analysis, limiting the ability to establish relationships.
Digital Object Identifier (DOI)
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