Original text from Janssen et al (2015), p. 87 (citation): "Our results strongly support a monophyletic grouping of the Microstomidae and the Dolichomacrostomidae—a clade we propose to name Dolichomicrostomida—and they do not support the traditional placement of the Microstomidae at the base of the Macrostomorpha. The presence of asexual fissioning was thought to be a basal trait, linking the Microstomidae with the Catenulida, a hypothesis clearly rejected by our ASR (see Section 3.3.1). Tyler (1976), in a comparative study of adhesive gland morphology, concluded, with cautious reservation, that the Microstomidae may be closer to the Macrostomidae, with which they share insunk anchor cells and long papillae, than to the Dolichomacrostomidae, which have a similar branching pattern of the releasing gland neck. He also suggested that the association between rhabdites and adhesive papillae indicated a closer association of Dolichomacrostomidae to Bradynectes than to the Microstomidae. Both hypotheses are rejected by our results. Indeed, Rieger (2001) argued that the insunk anchor cells could have evolved convergently, as the anchor cells in the Microstomidae are not insunk as deeply as those in Macrostomum, and that the association between rhabdite glands and adhesive papillae is debatable, suggesting a closer relationship between the adhesive glands of the Microstomidae and Dolichomacrostomidae. Likewise, Riedel (1932) grouped Microstomidae and Dolichomacrostomidae, based on similarities in the process of oogenesis. Finally, two rDNA based molecular phylogenies (Littlewood et al., 1999; Litvaitis and Rohde, 1999) also recovered this grouping, albeit with low taxonomic coverage of the Macrostomorpha. Despite the strong molecular evidence for the Dolichomicrostomida there are currently no morphological apomorphies to diagnose this clade."
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