2008/07/28 by M. Hess, F. X. Beck, Heidemarie Gensler +3 · 12 citations
Earth and Planetary Sciences · Environmental Science · #Marine Biology and Ecology Research #Marine Bivalve and Aquaculture Studies #Marine and coastal plant biology
paper · pdf · doi:10.1093/mollus/eyn030
openalex publication_date 2008/07/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/23
The helicoid microgastropod genera Leptogyra, Xyleptogyra and Leptogyropsis from deep, sunken wood off New Zealand, were originally classified among the poorly defined Skeneidae (Vetigastropoda, Trochoidea) based on shell characters, external morphology and fine-structure of radulae. We investigated the microanatomy and histology of several representatives by means of serial semi-thin sectioning followed by computer-aided 3D-reconstruction, studied the shell structure, and performed phylogenetic analyses of histone (H3) and COI-sequences in order to substantiate the neomphalidan nature of these genera. The anatomical data, in particular the lack of sensory papillae, the presence of a single left kidney, left-side innervated copulatory organs, glandular gonoducts, eggs without a vitelline layer, a single pair of radular cartilages, a rectum passing beneath the heart and statocysts with a single statolith clearly exclude Leptogyra, Xyleptogyra and Leptogyropsis from the Skeneidae and from the Vetigastropoda as a whole, but strongly suggest a systematic position among the Neomphalida, where the small, helicoid genus Melanodrymia shows most similarities. This conclusion is also supported by shell structure (in particular by the presence of shell pores similar to Neomphalus), and by the molecular trees. Similar to whale falls, the sunken wood habitat might have served as an ecological bridge between the ancestral regular deep benthos and the hydrothermal vent habitat otherwise typical for Neomphalida. We argue that Neomphalida is a separate basal clade of rhipidoglossate Gastropoda.