Austrohinnites marwicki (Allan, 1946)
ALLAN, R. S. 1946. Hinnites (Pectinidae, Mollusca) from Tertiary strata, New Zealand. Records of the Canterbury Museum, 5 (2): 125-129, pls. 25-27. [p. 127, pl. 26, figs. 1, 2; pl. 27, figs. 1, 2]
1946 Hinnites marwicki Allan, 1946
R. S. Allan, 1946, plates 26, 27.
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«This species is closely related to H. trailli Hutton and is clearly derived from it. The holotype is somewhat larger than that of trailli but the main differences are found in the nature of the ribbing. The eleven-ribbed stage in marwicki is confined to the early neanic part of the shell, while on the later formed part of the pectinoid area there are about 20 ribs, more prominent than in trailli. The ostreiform part of the disc has the same number of ribs which are less clearly defined and tend to disappear towards the ventral margin. The ribs are ornamented by prominent, wide-spaced scales which project above the surface. The scaling commences towards the ventral edge of the pectinoid part of the disc where it is of the trailli type.
The holotype is a beautifully preserved left valve. The rightvalve is extremely thick, massive and heavy, with ribbing confined to a small area around the umbo. Otherwise it is completely ostreiform. Dimensions of holotype: length, 90 mm.; height,110 mm. Holotype in the Canterbury Museum (Cat. No. M421). Type locality: Hinnites shell-bed, Railway Cutting, Weka Pass (Uppermost Mount Brown Beds). Stratigraphical Range: The Hinnites shell-bed, well developed in the Weka Pass Stream, and in the railway-cutting above it, forms the base of the Uppermost Mount Brown Limestone (E) of Thomson. The faunal assemblage is part of what I have termed the epsilon-fauna. (Rec. Cant. Mus., IV (6) 1940, p. 289), which on stratigraphical grounds is clearly post-Hut chinsonian. This fauna is also found in Band 7 at Clifden. On the basis of a comparison of the macrofossils, mollusca and brachiopoda, I would correlate the Uppermost Mount Brown Beds with Band 7 at Clifden. However, I am informed by Dr. Finlay that his study of the foraminifera throws new light on the range of the epsilon-fauna. I do not wish to anticipate his results here. I include in Hinnites marwicki a beautifully preserved left-valve from Band 7A at Clifden. This is figured on Pls. XXVI and XXVII, figs. 2. (Canterbury Museum, Cat. No. M626). This form has more ribs than the holotype, and the sculpture is rather of the trailli-type, except that it is coarser (as in marwicki) and has the well-developed scales of marwicki. It may be that further material from Clifden will show that this form can be separated as a new species.» ROBIN SUTCLIFFE ALLAN, 1946
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