Glyphanostomum Levinsen, 1884

Reuscher, Michael G. & Fiege, Dieter, 2016, Ampharetidae (Annelida: Polychaeta) from cold seeps off Pakistan and hydrothermal vents off Taiwan, with the description of three new species, Zootaxa 4139 (2), pp. 197-208 : 202

Glyphanostomum Levinsen, 1884

Type species: Samytha pallescens Théel, 1879

Generic diagnosis (emended). Prostomium without glandular ridges. Buccal tentacles smooth. Three pairs of cirriform branchiae. Segment II without chaetae. Thorax with 14 chaetigers and 11 uncinigers. Modified thoracic unciniger 8 with elevated notopodia and dorsal glandular ridge absent or present. Two intermediate uncinigers. Abdominal rudimentary notopodia absent.

Remarks. The generic diagnosis had to be emended to accommodate the newly described species, which has a modified segment in the posterior thorax, reminiscent of the modification in the genera Anobothrus and Zatsepinia Jirkov, 1986 .

We decided against the erection of a new genus because all morphological characters, with the exception of the modified segment, agree with the generic diagnosis of Glyphanostomum . In contrast, Anobothrus , which is distinguished by a similar modification from Ampharete has additional morphological differences, most notably smooth, rather than pinnate, buccal tentacles.