Diagnosis: Shell medium-sized to large (43 98 mm) fusiform or turriform, with high spire. Protoconch normally multispiral, up to five whorls, later whorls bearing arcuate rather widely set ribs.
Spire whorls usually rounded, but sometimes distinctly shouldered due to strengthened angulate peripheral cord at mid-whorl or shifted towards abapical suture. In the latter case, spire whorls with flattened outline. Sculpture of strong spiral cords, sometimes with secondary cordlets. Cords widely spaced and sharp, often bearing fine brown threads on their crests (e.g. A. nadaensis and A. omnipurpurata) or strongly elevated, rounded or flattened, separated by deep grooves. Subsutural cord sometimes bi- or tripartite; sinus cord above periphery usually weaker than both preceding (subsutural) and succeeding (peripheral) cord. Peripheral cord usually the strongest, sometimes crenulate. Last whorl rounded or with notably angulate profile, usually abruptly constricted towards siphonal canal. Siphonal canal normally short and stout, rarely long and slender, unnotched. Aperture ovate, visibly constricted at transition to siphonal canal. Outer aperture lip with moderately deep U-shaped anal sinus, often lirate inside. Shell uniformly palé to uniformly brown, often with brown pattern of tiger bands or of regular dark-brown blotches on spirals, inner wall of aperture often with purplish colouration. Radula with elongated dúplex marginal teeth, often with notably thickened accessory limb. Central formation well-developed, with central cusp and lateral flaps fused without borders and looking like integral tooth, bearing long pointed central cusp.
Remarks: Powell (1966) included Pleurotoma annulata Reeve, 1843 in Turris (Annulaturris), along with the type species Pleurotoma amicta. While some subsequent authors accepted the validity of the subgenus, most did not. However, Fedosov et al. (2011) demonstrated the presence of two phylogenetic lineages witíiin Tunis, readily distinguishable on the basis of radular morphology. The first clade included the type species, Murex babylonius, and so the name Turris was applied to it, whereas the second lineage was provisionally ascribed to Annulaturris. This was based on the fact that the Philippine species identified by the authors as Turris annulata (but later found to be undescribed and named Turris kathiewayae) fell in the second clade, along with Turris postcristata, T cryptorrhaphe, T nadaensis and T. undosa, and shared a characteristic radular morphology. This ev-idence, nevertheless, was considered too weak for rearrangements of taxonomy, and the subsequent revisión of the genus (Kilburn et al, 2012) treated all relevant species as Turris.
Chase et al. (2022) synonymized Annulaturris with Turris without any justification and described the new genus Purpuraturris (type species Pleurotoma cryptorrhaphe), the scope of which corresponds to the clade defined by Fedosov et al. (2011) as Annulaturris. Here we present additional evidence for the close affinity of this lineage (which was also distinctive in the phylogenetic analysis of Zaharias et ai, 2024) with true Annulaturris. Although Annulaturris annulata and A. amicta have not been sequenced, their radulae, studied here (Fig. 5E), closely resemble the radulae of the sequenced Turris postcristata, T. cryptorrhaphe, T. nadaensis and T. undosa. These observations contradict the unjustified dismissal of the ñame Annulaturris by Chase et al. (2022), and because the ñame Annulaturris has priority over Purpuraturris, we restore it as a valid genus name for the respective clade. Nevertheless, if the type species Pleurotoma amicta, once sequenced, would prove to be unrelated to the Turris cryptorrhaphe complex, the name Purpuraturris would have to be restored as valid.
The species within Annulaturris, as defined here, exhibit a wide range of shell sizes, proportions and colour patterns. Species of Annulaturris share with Turris a characteristic position of the anal sinus, located above the whorl periphery, and indeed the boundaries between the two taxa have remained unclear for a long time. Distinction of the two taxa based on shell morphology is challenging, but a few characters have been observed in Annulaturris that do not occur in Turris species. These include gemmate spiral cords (A. kathiewayae), a very short siphonal canal resulting in a turriform shell [A. falároi and A. cryptorrhaphe), a purplish interior of the aperture (A. postcristata, A. nadaensis, A. undosa and A. cryptorrhaphe) and a characteristic tigerstripe colour pattern (A. postcristata, A. nadaensis, A. undosa, A. kantori,A. tanyspira and A. clausifossata). The allocation of A. tanyspira to Annulaturris is tentative and remains to be confirmed.


Distribution: Broadly distributed in the Indo-Pacific, from South Africa in the southwest to Japan in the north and east to the Marshall Islands and Fiji; at bathyal and subtidal depths.