Integrative phylogenomic and morphological evidence for Pseudothelogorgiidae fam. nov., with a redescription of Pseudothelogorgia hartogi (Octocorallia, Malacalcyonacea)

The octocoral genus Pseudothelogorgia van Ofwegen, 1994 has presented taxonomic challenges since its original description, with its higher-level placement uncertain and obscured by morphological convergence and lack of molecular data. Here, we integrate detailed morphological examination with phylogenomic analyses of newly collected shallow-water specimens from the Gulf of Oman, alongside a redescription of the type material.

Our results recover Pseudothelogorgia as a deeply divergent lineage within Malacalcyonacea, sister to Plexauridae but unrelated to Keroeididae, the family in which it was formerly placed. Distinct morphological characters, together with strong phylogenomic support, warrant the establishment of Pseudothelogorgiidae fam. nov. The shallow-water occurrences documented here extend the known depth range of the genus from mesophotic to shallow reef habitats, indicating ecological plasticity and highlighting the need for targeted exploration of under-surveyed Indian Ocean coral assemblages.