Tetraclitella Hiro 1939

Buckeridge, John S., 2008, Two new species and a new subspecies of Tetraclitella (Cirripedia: Thoracica) from the Cainozoic of Australia and New Zealand and a consideration of the significance of tubiferous walls, Zootaxa 1897, pp. 43-52 : 44

Genus Tetraclitella Hiro 1939

Diagnosis: Small, shell depressed, wall comprising carina, rostrum and paired latera, parietes permeated by numerous longitudinal pores, articular margins lacking teeth, radii broad with horizontal summits, permeated by horizontal pores; orifice rhombohedral; scutum transversely elongated without depressor muscle crests; tergum short, with short broad spur; base membranous or thinly calcareous.

Distribution and age: Miocene to Recent, hyperbiotic, littoral. Indo-west Pacific.

Type: Tetraclita purpurascens ( Wood, 1815) , in Hiro 1939: 273.

Remarks: With recognition of these new species and subspecies, there are 13 taxa within this genus ( Table 1 ), although very few of these have a fossil record. This reflects the relatively high-energy environment that Tetraclitella typically inhabits.

Specimens of the earliest Tetraclitella have been described from the Miocene of both northern New Zealand and Victoria, Australia ( Buckeridge, 1983). At that time, there were no complete shells available for study, and as Tetraclitella purpurascens ( Wood, 1815) was considered to be a trans-Tasman species, all the available material was combined and described as Tetraclitella sp. cf. T. purpurascens ( Wood, 1815) . This cautious decision now requires re-evaluation following the revision of a number of shallow water barnacles from the region by Foster and Anderson (1986), who showed that Tetraclitella purpurascens ( Wood, 1815) was confined to southern Australia.