34


Journal of Paleontology 90(1):31–42


(Danian, early Paleocene) rocks; these are Wangaluta henaconstricta n. gen. n. sp. and Alcithoe s.l. wangaloaensis n. sp., and are described below. These new records are of apparently endemic, short-lived taxa with little in common compared with Paleogene volutes within and outside the Zealandian region in the Gondwana realm, further attesting to New Zealand geographic and genetic isolation during the Paleocene. In addition, a possible ‘Wangaloan’ volute here referred to Volutidae? n. sp., attributed tentatively to an early Fulgorariine, is recorded form the Steel Greensand of East Taieri, Dunedin. Paleopsephaea neozelanica Finlay and Mar- wick, 1937, is reassigned questionably to Wangaluta n. gen. More than 40 years after the initial discovery of fossils at


Wangaloa, the first papers on these significant earliest Cenozoic fossils were published by Henry Suter (1911) and Patrick Marshall (1916, 1917) on a few characteristic, common elements in the Wangaloa Formation, but it would not be until Finlay and Marwick’s (1937) epic monograph on the ‘Wangaloan fauna’ that the assemblages preserved at Wangaloa and Boulder Hill would receive the taxonomic treatment they deserved. The very hard, concretionary sandstone renders any fossil preparation difficult with specimens being notoriously hard to extract without breakage. Amongst the best preservation of the Wangaloan assemblages are to be found at Boulder Hill, and as Finlay and Marwick relayed, they collected ‘out’ a small lens of loose specimens, which were beautifully preserved. Few works have been published since on the ‘Wangaloan’ molluscan faunas, except for a checklist of coeval taxa in localities other than Wangaloa and Boulder Hill in Fleming in Harrington (1958), a review of the Paleocene assemblages in Beu and Maxwell (1990), a paper on three new taxa from the Wangaloa Formation by Stilwell (1993), and a PhD thesis by Stilwell (1994), monographing the entire fauna with new taxa. A further volutid, Teremelon onoua n. sp. (Fig. 6), is repre-


sented in upper Paleocene rocks of Chatham Islands, south-western Pacific (Figs. 3, 4; Campbell et al., 1993, table 4.11; Stilwell, 2003, appendix, p. 346), collected in 1977 on Pitt Island, and is not closely allied with the ‘Wangaloan’ forms recorded from the Sobral Formation of Seymour Island, Antarctic Peninsula; this species is probably an early undescribed Alcithoe (W.J. Zinsmeister, unpublished data, 1990; J.D.S., personal observation).As far as I amaware, no Paleocene volutes have been recorded from either Australia or South America (oldest in Patagonia are middle? Eocene, del Río and Martínez, 2006; however, new research indicates the possibility of volutes in the Patagonian record, but they remain undescribed, see del Río and Martínez, 2015) and few Cretaceous volutes have been reported from the Southern Hemisphere apart from probable early records from the Late Cretaceous of India by Stoliczka (1867) and Late Cretaceous of Pondoland, South Africa by Woods (1906), who identified species belong to Fulgoraria, Athleta, Volutilithes,and Lyria. The early Paleogene volutid gastropod record is poor in the Southern Hemisphere in contrast to coeval taxa in the north. The presence of perhaps as many as four volute species in the ‘Wangaloan’ significantly extends the stratigraphic range from the late early Paleocene to early? -middle Eocene and sig- nificantly expands our knowledge of the early evolution of the Volutidae in the Zealandia region (Fig. 5). Significantly, these new volute taxa, along with the large number of Paleocene


Figure 4. Southern cliff section of the RBT denoted by the red arrow, which is non-slumped and in situ. The only access to the fossiliferous outcrops is in the slumped section and at low tide along the wave-cut platform.


invertebrates now recorded from the Zealandian Paleocene, belonged to the shrinking Weddellian Biotic Province of W. J. Zinsmeister (see Zinsmeister, 1982; Stilwell, 2003), which had all but disappeared by the mid-Paleogene.


Systematic paleontology


Superfamily Muricoidea Rafinesque, 1815 Family Volutidae Rafinesque, 1815


Phylum Mollusca Linnaeus, 1758 Class Gastropoda Cuvier, 1797


?Subfamily Fulgorariinae Pilsbry and Olsson, 1954 Wangaluta new genus


Type species.—Wangaluta henaconstricta new species (by original designation).


Diagnosis.—Medium-sized, moderately robust volute with subtrapezoid and medially concave whorls; spire angle approximately 43°; sutures moderately clasping, wrapped around axials of succeeding whorls, partially concealing axials; last whorl with adapical, subsutural, convex, swollen band or welt about 5.0mm broad, bordered abapically by moderately strong constriction; basal constriction moderately rapid to rapid; sculpture of 14 widely spaced, strong, axially extending ribs that fade adapically at constriction and weak spiral threads; axials on spire whorls strongest at abapical third;


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