Beu: Evolution of Janthina and Recluzia 
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collected by C. A. Fleming from the lowest lens of Nukumaru 
Limestone on the Waitotara coast, west of Whanganui 
(Fleming, 1953b: 139). This formation was labelled “not 
resolved” stratigraphically by Abbott et al. (2005: fig. 3), 
i.e., it is significantly older than MIS 77, the oldest MIS 
stage recognized in the analysis by Abbott et al. (2005), but 
younger than the Pliocene-Pleistocene boundary in MIS 
103. Darkies Spur Formation on Darkies Spur Road, west 
of Devil’s Elbow, c. 30 km north of Napier, Hawke’s Bay 
(Haywick & Henderson, 1991; Haywick etal, 1991, 1992; 
Haywick, 2004) has yielded one specimen and a fragment 
(Figs 281, K). Several specimens were collected by D. Cowe 
(Greytown) from a thin shell lens within “undifferentiated 
Upper Okiwa Group” (Fleming, 1953: 133-136) between 
Tuha Sand and Ohingaiti Sand in a road cut on Highway 
1 uphill from Makohine Stream, 2 km south of Ohingaiti, 
Rangitikei Valley (one specimen in GNS; Figs 28B, E, 
H). The youngest record of Janthina chavani in New 
Zealand lies within early Calabrian (Pleistocene) rocks: one 
incomplete specimen from a shellbed enclosing Vinegar 
Hill Tephra (MIS 61, 1.75 Ma; Pillans et al. , 2005: 79, figs 
5A, 11), within Tewkesbury Formation (late Nukumaruan) 
on Brunswick Road, Kai Iwi Valley, west of Whanganui 
(locality illustrated in colour by Townsend et al , 2008: 
fig. 35). The stratigraphical positions of Whanganui Basin 
specimens are shown in Fig. 17. 
New Zealand successions are important for indicating 
an abrupt, apparently punctuational speciation event when 
Janthina chavani (Mangapanian and Nukumaruan New 
Zealand Stages, late Piacenzian-early Calabrian) originated 
from J. typica (Kapitean, Opoitian and Waipipian New 
Zealand Stages, late Messinian-early Piacenzian) at 3.0 Ma. 
The one post-Nukumaruan fossil record of Janthina in New 
Zealand is a Holocene specimen of J. janthina from Table 
Cape, Mahia Peninsula (see below under J. janthina). Thick, 
younger, normal marine successions crop out extensively 
in New Zealand, in Nukumaruan successions throughout 
Hawke’s Bay and Wairarapa district, in the Castlecliffian 
succession at Cape Kidnappers, Hawke’s Bay, and in the 
Nukumaruan-Castlecliffian successions in Whanganui 
Basin and North Canterbury. They record complex glacial- 
interglacial sequences deposited during the last 1.63-0.3 
Ma (Fleming, 1953b; Naish et al ., 1998). However, apart 
from the one Holocene specimen, Janthina fossils have not 
been recorded from rocks younger than MIS 61. There is no 
reason to assume that Janthina chavani became extinct at 
1.75 Ma, however. The lack of specimens probably simply 
results from sea temperatures being too cool around New 
Zealand to be inhabited by Janthina , particularly during 
glacial stages. The sparseness of Janthina fossils younger 
than Waipipian might also have resulted partly from a lack 
of persistent onshore winds after 3.0 Ma. This conceivably 
resulted from sheltering of basins in eastern New Zealand 
from prevailing westerly winds as a result of changing 
paleogeography, e.g., late Pliocene-Pleistocene uplift of the 
central mountain ranges, rather than from a lack of Janthina 
specimens in the seas around New Zealand. 
The succession in southern Australia. Successions from 
which fossil Janthina specimens have been collected occur 
widely but sparsely across southern Australia (Figs 18-19). 
The relative ages of all these formations, other than those 
on Kangaroo Island, South Australia, were summarized by 
Darragh (1985) and refined by Beu & Darragh (2001: fig. 
6), based on pectinid bio stratigraphy. However, correlation 
with international stages is less precise than in New Zealand. 
Janthina typica (= Heligmope dennanti Tate, 1893) was 
first recorded by Tate (1893) from Grange Burn Formation 
(Zanclean) at “MacDonald’s bank”, on Muddy Creek, near 
Hamilton in western Victoria. The fauna at this locality forms 
the basis of Darragh’s (1985: 106) molluscan assemblage 
XVI (Kalimnan Australian Stage). Janthina typica also 
occurs in the same formation nearby at Grange Burn, a 
tributary of Muddy Creek. It also occurs uncommonly at one 
locality (road cutting at Bunga Creek, Princes Highway) in 
Jemmys Point Formation near Lakes Entrance in Gippsland, 
easternmost Victoria, within the same Kalimnan molluscan 
assemblage XVI (Zanclean). It is surprising that J. typica 
does not occur more widely in Jemmys Point Formation, 
which is richly fossiliferous and crops out extensively around 
Lakes Entrance in Gippsland. Janthina fossils similarly are 
absent from Cameron Inlet Formation (Pliocene) and the 
overlying Memana Formation (early Pleistocene) on Flinders 
Island, Bass Strait, again despite highly diverse faunas and 
extensive outcrop and collecting. As with the more southern 
New Zealand outcrops, eastern Victorian and Bass Strait 
localities presumably were either too cool for Janthina to 
occur or lay outside areas where water movements or wind 
carried Janthina specimens into shallow water. 
Ludbrook (inMilnes etal., 1983: 23) cautiously recorded 
“what may be Hartungia dennanti dennanti ” (i.e., Janthina 
typica) among poorly preserved molluscs collected from an 
unnamed early Pliocene limestone unit overlying Kingscote 
Limestone at Table Rock, near Point Reynolds, south coast 
of Kangaroo Island, South Australia. The only other record 
of J. typica from Australia is in Tate’s type material from 
Hallett Cove Sandstone, Adelaide. One incomplete specimen 
among the syntypes of H. dennanti from Hallett Cove is J. 
typica , with an evenly subspherical shape, a low spire, and 
prominent spiral folds over the entire exterior. Tate’s two 
other syntypes from Hallett Cove Sandstone are J. chavani. 
Parkin (1969: 220, fig. 115) provided a photograph of the 
coastal exposure near Blanche Point, on the coast south of 
Adelaide, showing “Hallett Cove Sandstone, upper bed of 
?Pleistocene limestone over a lower bed of Pliocene sand”. 
The two species evidently are segregated stratigraphically 
at Hallett Cove, late Piacenzian-Gelasian specimens of J. 
chavani occurring higher in the section than early Piacenzian 
specimens of J. typica. It seems likely that Hallett Cove 
Sandstone spans at least the central part and perhaps all of 
the Piacenzian Stage. Marine successions in Victoria have 
not yielded J. chavani. 
Bridgewater Limestone, a complex series of late Pliocene- 
Pleistocene-Holocene marginal marine units deposited 
during interglacial high-stands, crops out extensively south- 
westwards from Naracoorte to the present coastline in 
southeastern South Australia (Sprigg, 1952; Murray-Wallace 
etal. , 2001; Blakemore etal., 2015). It includes unusual thin 
(5-10 cm thick), laterally continuous, strongly cemented 
limestone beds with concentrations of huge specimens of 
Janthina chavani covering large bedding-plane exposures in 
some lime quarries near Naracoorte, alternating with thicker 
unconsolidated sand beds barren of macrofossils. This was 
observed by the writer and T. A. Darragh (Museum Victoria) 
at Henske’s Quarry, Elderslie Road, 2.6 km southeast of 
Naracoorte. Here Janthina chavani is abundant in a few thin 
