Cancellocochlea heatherae, Shea & Colgan & Stanisic, 2012

Shea, M., Colgan, D. J. & Stanisic, J., 2012, 3585, Zootaxa 3585, pp. 1-109 : 80

Cancellocochlea heatherae n. sp.

( Figs 29H; 31H; 33H; 35H; 37E)

Etymology. For Heather, daughter of the late Graeme Annabell.

Diagnosis. Shell (slightly sub-adult) very small, pale orange-brown, biconcave with depressed spire. Protoconch sculpture spiral comprising 20 prominent, crowded, beaded spiral cords and very weak, regularly spaced, curved radial ridges which become more prominent toward the protoconch/teleoconch boundary. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, prosocline to orthocline radial ribs. Ribs on body whorl 108. Umbilicus wide U-shaped.

Type material examined. Holotype. AM C.464074, Pacific Highway rest area south of Johns River, north of Taree, NSW (31˚45´53” S, 152˚40´19” E), 17.x.2000, coll. G. Annabell. Paratype. AM C.472879, same locality as holotype .

Description. Shell slightly sub-adult, very small, pale orange-brown, biconcave with depressed spire. Whorls 3.85, tightly coiled, the last inflated and descending in front. Sutures strongly impressed. Shell diameter 3.03 mm, height 1.55, H/D 0.51. Protoconch flat, of one whorl, diameter 0.46 mm. Protoconch sculpture spiral comprising 20 prominent, crowded, beaded spiral cords and weak, regularly spaced, curved radial ridges which become more prominent toward the protoconch-teleoconch boundary. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, prosocline to orthocline radial ribs. Ribs on body whorl 108, width of interstices on the first teleoconch whorl equal to or greater than width of four ribs; on the penultimate whorl equal to or greater than width of six ribs; each rib with two or more periostracal blades. Interstitial sculpture of low prominent microradial ribs and low, weaker microspiral cords forming weak beads at their intersection; number of microradials between ribs on the first teleoconch whorl 6–7; on first quarter of body whorl 8–9. Aperture broadly ovately-lunate. Parietal callus prominent, transparent. Umbilicus wide U-shaped, diameter 0.88 mm, D/U 3.43. Based on one measured sub-adult.

Anatomy unknown.

Distribution and habitat. Known only from the type locality; found in sclerophyll forest, presumably under logs.

Remarks. Cancellocochlea heatherae n. sp. is known only from the type locality. Although only the type and another slightly sub-adult specimen were available for study, a formal description of the species is provided at this time because it represents yet another grade of shell organisation in an area which the nautiliform charopids appear to be extremely diverse. The shell morphology (protoconch sculpture, shell coiling, umbilical shape) is similar to Planorbacochlea from the Hunter/Port Stephens area. COI and ITS-2 DNA sequences showed the species to be more closely related to Ca. coolongolook than P. planorbis . However, this does not necessarily indicate close relationship with Cancellocochlea s.s. given that Ca. coolongolook has a reticulate protoconch. These seemingly conflicting results would seem to question the reliability of using protoconch sculpture as an accurate indicator of generic placement. However, it more probably indicates the need to categorise the protoconch types more carefully in terms of their micro-architecture.