Few species of animals or plants reproduce only asexually--and those that do seldom make up an entire genus, let alone a taxon of higher rank. These observations have been taken to mean that the loss of sexual reproduction is a dead end in evolution, leading to early extinction. Against this generalization, the entire Class Bdelloidea of the Phylum Rotifera stands out as an apparently radical exception, an "evolutionary scandal"

Welch, D. M. and M. Meselson (2000). Evidence for the Evolution of Bdelloid Rotifers Without Sexual Reproduction or Genetic Exchange. Science 288(5469): 1211-15.

Nothing here.