Tertiary Mollusca from South-East Wairarapa
[Read before Wellington Branch by title April 9, 1953; received by Editor, April 14, 1953.]
Molluscan fossils are described from Miocene and Plio-Pleistocene rocks in South-East Wairarapa. Descriptions include 3 new genera (Wairarapa, Maoricrassus, Mangaoparia), a new subgenus of Awateria (Mioawateria), 22 new species, a new subspecies and a new name.
The nature, age and distribution of the fossiliferous sediments are discussed briefly, and the Hurupi Formation is redefined.
The fossils described in this paper were collected during the last six years by M.Sc. students of the Geology Department, Victoria University College, and by the writer while on the staff of the same department. The collections come from a much greater area than that covered by L. C. King (1933) and R. K. Dell (1952), although most of the sediments that have yielded fossils are of the same age as either the “Onoke Series” (Waitotaran to Nukumaruan) or the “Hurupi Series” (lower Tongaporutuan) of King. In addition, fossils have been collected from:
Blue-grey sandstone and mudstone in the Te Wharau Syncline (Mac-Beath, 1950) and near the Brocken Range, correlated with the Altonian, Clifdenian and Lilburnian stages.
Blue-grey mudstone of middle Tongaporutuan age overlying basement rocks west of the Mangaopari Fault, in Mangaopari Stream and in Bell's Creek (tributary of the Mangaopari flowing north between Big Hill and Te Ahitaitai trigs).
This paper is chiefly the result of the writer's research at the Geology Department, Victoria University College, from 1950 until 1951. Much of the new material collected remains undescribed.
Outline of Stratigraphy
The two new Southlandian species were collected from compact blue-grey silty mudstone in the south branch of Whakatahine Stream about a mile north of the Motukai Road. The associated fauna includes a Neocola closely related to N. demissus Marwick, described from the basal Tutamoe conglomerate of Gisborne district. The Wairarapa horizon is about the middle of the Southlandian sequence which comprises several thousand feet of beds, chiefly blue-grey mudstone. The lowest Foraminifera obtained from these beds, from about 500 feet above the base, appear to be Clifdenian, but Mollusca from the basal beds suggest that they are Altonian. The lower Tongaporutuan Hurupi Formation overlies the Southlandian beds, generally with disconformity but locally with unconformity. The
fossils in the south branch of the Whakatahine River are therefore about Lilburnian or upper Clifdenian.
The name Hurupi Formation was used by MacBeath in his unpublished M.Sc. thesis (1950), and by the writer in subsequent mapping, for the Hurupi Series of L. C. King (1933, p. 334). As defined by King the Hurupi Series includes all the fossiliferous rocks at Hurupi Creek overlying the basement and underlying unfossiliferous mudstones in the Palliser Bay Cliffs north-west of Hurupi Creek. The term requires further definition to allow its use for rocks further afield. The formation consists chiefly of compact blue-grey sandy mudstones between 1,000 and 1,500 feet thick; the lower part is coarser and usually sorted into alternating layers, while the upper part is finer and typically quite massive. Generally there is a fine basal conglomerate six to twelve inches thick. The fossil Mollusca are diagnostic of the formation and were used by MacBeath and the writer to identify it in the field. King (1933, p. 334) and Dell (1952, p. 85) remarked upon the striking uniformity of the faunas from Putangirua Stream and Hurupi Creek. The Hurupi Formation is equally uniform in fossil content throughout its extent, and the field worker can rely on finding in it several of the following easily identified Mollusca: Callusaria callosa Marw., Maoricrypta radiata (Hutt.), Polinices huttoni v. Iher or closely related forms, Acominia hendersoni (Marw.), Alcithoe hurupiensis Marw., Glycymeris hurupiensis Marw., Cucullaea n.sp., Limopsis lawsi King, Dosinia cottoni Marw., or D. macroptera Fleming, Marama hurupiensis Marw., Eumarcia thomsoni Marw.
The Hurupi Formation has been identified by the above criteria overlying basement on the north-east side of the Haurangi Range, and along the valleys of the Pahaoa and Wainuioru rivers. North of the junction of the Wainuioru and the Kuamahanga Stream, the Hurupi Formation overlies Southlandian rocks for a distance of several miles along its strike.
Dell (1952, pp. 85–86) has discussed the age and facies of the Hurupi beds and classed them in the Tongaporutuan Stage. The Geological Survey paleontological staff have long regarded them as lower Tongaporutuan. Further information on the age of the formation was obtained from collections of Foraminifera made by R. A. Couper and the writer from the cliffs north-west of Hurupi Creek. Here the whole of the Hurupi Formation and a part of the underlying greywacke are repeated by a fault clearly exposed in the cliff, striking north-north-east and running out to sea a few chains west of Hurupi Creek. The results of the collection are summarised as follows:—
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|Mudstone, sandstone, shell-beds||more than||Nukumaruan to Kapitean|
|Fine blue-grey mudstone without macrofossils.||600 feet||upper Tongaporutuan|
|200 feet||middle Tongaporutuan|
|300 feet||middle Tongaporutuan|
|Hurupi Formation.||500 feet||lower Tongaporutuan|
|300 feet||uncertain (no micro-fauna)||Unconformity.|
The lower Tongaporutuan determination is based on the presence of Bolivinita quadrilatera (Schwager) and the absence of B. pohana Finlay; middle Tongaporutuan on the presence of B. pohana without B. compressa Finlay; upper Tongaporutuan on the presence of B. compressa. The Foraminifera thus show
that the uppermost part of the Hurupi Formation here is middle Tongaporutuan, the bulk of it, probably including the lowest beds, is lower Tongaporutuan.
Elsewhere neither B. quadrilatera nor B. pohana has been found in the formation. In most sections, however, mudstones containing B. pohana overlie the formation so that its upper beds may always represent the lower part of the middle Tongaporutuan.
MacBeath and the writer consider the Hurupi Formation to be the first beds deposited during a widespread transgression over south-east Wairarapa. Dell's remarks (1952, p. 85) are consistent with this view. He states that “deposition was rapid, in depths equivalent to comparatively shallow off shore waters to-day.” The formation is not clearly marked off from the overlying beds, grading upwards to fine-grained mudstones without Molluscan fossils. Grit, coarse sand, shellbeds, and generally well-sorted sediments are characteristic of the lower beds in most localities. Higher beds are mostly massive sandy mudstones interbedded with rare sandy phases. Probably, therefore, the lower beds were deposited in shallow water; depth increased with time at a rate probably depending on the rate of recession of the shore-line due to subsidence. The Hurupi Formation thus is not uniform in facies but represents a series of facies in a constantly changing environment of deposition.
Couper (1948) described and mapped the Bell's Creek beds, and classed them as middle Tongaporutuan, from a microfaunal determination by Dr. H. J. Finlay. The Mollusca are quite consistent with this determination. The Bell's Creek beds, in contrast to the Hurupi Formation, are fine blue-grey mudstone containing sparse, angular particles of greywacke of grit size. They overlie a conglomerate resting on the basement. The mudstones lack bedding, but apparently the sea bottom was subject to a good deal of disturbance during their deposition, for many of the molluscan fossils present have been broken during growth.
The fauna includes many small species not hitherto recorded from the Wairarapa. The largest fossils collected are Marshallena curtata (Marw.) and species of Ellicea. Marshallena curtata and Marginella aff. whitecliffensis Marw. link the Bell's Creek mudstone with the middle and upper Tongaporutuan of North Taranaki. Gemmula peraspera (Marw.) in the Mangaopari Stream is elsewhere known only from the Ormond Series of Gisborne district (Marwick, 1931, p. 32).
Fossiliferous Pliocene rocks of the district have already been discussed (Vella, 1953).
Mr. R. A. Couper and Mr. D. M. MacBeath collected fossils in south-east Wairarapa and left well-labelled material in the collection of the Geology Department, Victoria University College Collections made by Mr. D. Campbell, in 1951, have also been available for study.
Dr. J. Marwick and Dr. C. A. Fleming, New Zealand Geological Survey, have helped in the identification and description of fossils. Dr. Fleming has guided the writer in the task of searching for references, and his help in the past to several Victoria College students in determining fossils for their M. Sc. theses is here acknowledged. Free access to the Geological Survey collections and library has been a great practical help.
The holotypes of new species will be deposited with the New Zealand Geological Survey.
Genus Pectunculina dapos;Orbigny, 1843
Paleontologie Francaise: Terrain Cretace, vol. 3, p. 182.
Type Species, by subsequent designation (Sacco, 1898) Pectunculus scalaris Sowerby, Eocene, London Basin.
The distinguishing characters of P. scalaris are its denticulate margins and moderately strong radial riblets crossed by weaker concentric sculpture. Aspalima Iredale, 1929, appears to be a synonym, since the type species (by original designation Limopsis erectus Hedley and Petterd, 1906 [390 fathoms off Sydney, Recent] differs chiefly in its much finer radial sculpture and deeper cardinal area, both of which seem to be quite variable features. The Jamaican Miocene form P. ovalis silova Woodring, 1925, has weaker radials than scalaris and erectus. The new species described below has very weak radials anteriorly and medially but quite strong radials posteriorly, and cannot be separated generically from either erectus or scalaris. The recent north Atlantic Limopsis minuta (Phil), referred to Pectunculina by Cossman and Peyrot (1913, p. 201), is very similar in outline to erectus and has similar fine radials, but differs in its very shallow cardinal area, and wide chondrophore. Wood's figures of L. scalaris (1864, Pl. XVII, figs. 9a, b) however, show a cardinal area similar to that of the new species here described—i.e., shallower than in L. erectus but deeper than in L. minuta.
Another New Zealand species of Pectunculina is Limopsis lata E. A. Smith, 1885, from 700 fathoms off the north-east coast (Challenger Station 169). Pectunculina lata (E. A. Smith) has a comparatively broad shell with fine radial sculpture.
Pectunculina is generally used as a sub-genus of Limopsis, but the long Tertiary history of small shells with denticulate margins justifies generic separation (compare Iredale, 1929).
Pectunculina aoteana n.sp. (Plate 26, figs. 9, 10.
Shell very small, sub-circular, nearly equilateral. Sculpture, about 18 broad, bevelled, concentric ridges, irregularly spaced, crossed by faint, narrow, distant radial ribs strongest at the posterior end. Cardinal area short and shallow, chondrophore wide. Five posterior teeth, seven anterior.
Height, 4·8 mm.; length, 4·8 mm.; thickness (1 valve), 1·7 mm.
Localities: N165/507 (holotype, a left valve) and N165/508 (an imperfect right valve), Bell's Creek, middle Tongaporutuan.
Myrtea haurangiensis n.sp. (Pl. 26, figs. 7, 8.)
Closest to M. papatikiensis (Marw.) but larger, with shorter, more concave anterior dorsal margin and longer, more convex posterior dorsal margin. Unlike M. papatikiensis, haurangiensis tapers posteriorly and the posterior end is vertically truncated. Sculpture, sharp, spaced concentric lamellae, about 4 per mm., with very faint concentric striations in the interspaces; radial sculpture lacking.
i pulcherimus n. sp. paratype (N165/507), × 6
Fig 2—Awateria striata n.sp., holotype, × 8.
Fig 3—Austrosassia pahaoacusis n. sp, holotype, × 2.
Fig 4—Antiguraleus maarainsis n. sp, holotype, × 8.
Fig 5—Bathytoma wairarapaensis n. sp, holotype, × 29.
Fig 6—Venustas couperi n. sp. holotype × 19
Fig 7, 8—Myrtea haurangiensis n. sp, holotype. × 5
Fig 9, 10—Pectunculina aotcana n.sp holotype. × 7.9
Fig 11—Baryspira macbeathi n. sp, holotype. × 13
Fig 12—Micantaper murdochi (Fin) prior n. subsp, holotype, × 27
Fig 13.—Antigui [ unclear: ] aleus rishworthi n. sp. holotype, × 11.8.
Fig 14.—Conospu [ unclear: ] us brockenensis n. sp. holotype. × 3.4
Fig 15.—Verillitra wainuioruensis n. sp., holotype, × 6.9
Fig 16.—Verillitra marwicki n. sp. holotype, × 7
Fig 17.—Micantapex pulcherimus n.sp, holotype, × 4.3.
Fig 18.—Awateria (Mioawateria) pahaoaensis n. subg, n. sp, holotype. × 6.8
itor flemingi n.sp, holotype, × 4.5
Fig 20.—Wairarapa rebeca n. gen. n.sp., holotype, × 7.9.
Fig 21.—Maoricrassus carinatus n. gen, n. sp, holotype, × 7.9.
Fig 22.—Splendrillia whangaimoana n.sp, holotype, × 5.3.
Fig 23.—Neoguraleus hautotaraensis n. sp, holotype, × 11.2
Figs 24. 25—Comitas terrissae n. sp. 24 paratype. × 4.3, 2.5, holotype. × 3.1
Figs. 26. 27.—Mangaoparia powelli n. gen n. sp. 27, holotype, × 10.8; 26. paratype (N165/507), × 11.
Fig 28.—Awateria mwoecnica n. sp. holotype, × 63.
Anterior adductor impression large, sub-oblong, with a re-entrant nick on the inner side; posterior impression oval, smaller; pallial line distinct and narrow.
Height, 6·2 mm.; length, 7·7 mm.; thickness (1 valve), 1·7 mm.
Localities: N165/507 (Holotype a right valve), G.S. 4517 (2 paratypes). Bell's Creek, Middle Tongaporutuan.
M. papatikiensis was described from Urenuian beds in North Taranaki, a horizon probably a little higher than that of Bell's Creek. M. haurangiensis appears to be intermediate between papatikiensis and the Southlandian supra-flexa Marw. The latter has the umbones further forward than haurangiensis and the anterior dorsal margin more strongly concave.
Taras (Zemysina) cf. globus (Finlay).
1926 Zemysia (Zemysina) globus Fin, Trans. N.Z. Inst. 56: 462; figs. 109–111.
Four complete shells (two from L. C. King's collection) have been crushed, but agree closely with recent specimens of Z. globus. King (1933, p. 339) identified his specimens as Zemysia zelandica (Gray).
Locality: N166/522, junction of the Martinborough-Hinakura and Gladstone Roads, Pelicaria media Zone (middle Nukumaruan).
Venustas couperi n. sp. (Pl. 25, fig. 6).
A shell intermediate in most characters between V. spectabile (A. Ad.) and V. foveauxeana Dell. Sculpture of granulose spiral threads similar to those of foveauxeana, but only fifteen in number on the body whorl and base. About the same height as foveauxeana, but more like spectabile in outline; whorls lightly convex with a narrow, flattened shoulder bordering the upper suture, giving a slightly staged appearance, body-whorl sub-angled at the periphery. The apex is broken off the holotype, leaving four whorls.
Height, 34.5 mm.; diameter, 36 mm.
Locality: N165/515, east side of Makara Stream, north of Te Awaite Cutting, top of Pelicaria acuminata zone (Lower Nukumaruan), unique holotype.
The subantarctic Chlamys delicatula (Hutt.) is abundant and widespread in the Nukumaruan of east Wairarapa and the presence of Venustas couperi, a relative of two sub-Antarctic species, in beds of the same age, is further evidence in favour of the hypothesis of a northward advance of cold waters during the Lower Nukumaruan epoch (Fleming, 1944).
Venustas couperi is named after Mr. R. A. Couper.
Struthiolaria (Callusaria) aff. spinifera (Marwick).
1924 Struthiolaria spinifera Marw. Trans. N.Z. Inst., 55: 177, Pl. 13, fig. 3.
Differs from spinifera chiefly in the callus, which is a little heavier and rises higher just in front of the aperture. The callus is much lighter than in typical callosa.
Only one moderately well-preserved specimen has been collected; Callusaria is so variable that a range of specimens is needed for taxonomic work.
Locality: N162/629, South branch of Whakatahine Stream, north-west of Brocken Range, basal beds (Altonian?).
Architectonica (Discotectonica) hokianga nom. nov.
1948. Architectonica (Discotectonica) marwicki Laws, Trans. Roy. Soc. N.Z., 77 (1): 149, Pl. 12, fig. 20 (not Architectonica marwicki Allan 1926, Trans. N.Z. Inst. 56: 338, Pl. 76, fig. 2).
Dr. C. R. Laws, Auckland University College, has invited the writer to rename this species.
One specimen, incomplete, with the base imbedded in matrix. The surface has ornament very similar to that of the specimen described and figured as Architectonica (Discotectonica) n.sp., by Marwick (1931: 103, Pl. 10, fig. 179). Each whorl has four evenly spaced narrow spiral grooves with the interspaces divided by weak distant axial grooves, and bears a strong moniliform cord at the periphery.
Diameter, about 10 mm.; height, about 4 mm.
Locality: N162/630, Upokongaruru Stream, east of the end of the Motukai Road, about 500 feet above basement. Foraminifera collected from the same locality are Clifdenian, but closely underlying beds are probably Altonian.
Austrosassia pahaoaensis n.sp. (Pl. 25, figs. 3)
Closely related to A. zealta Laws and A maoria Finlay. Similar to maoria in size and proportions. Lower peripheral row of tubercles less strongly developed so that the peripheral area is not vertical but contracts downwards; four main spiral cords on the body whorl as in maoria; in that species they cross the varices without increase in size, but in the new species they are raised to spines on the varices and have concave interspaces, especially between the upper two. Above the peripheral carina between penultimate and antepenultimate varices are sixteen fine spiral threads, of which the fourth, eighth, twelfth, fourteenth and sixteenth (counting from the suture) are stronger than the others, and distinctly but very finely gemmate. Between the peripheral rows of nodules are five moderately strong spiral threads with weaker intermediates; between each pair of spiral cords below the periphery are five spiral threads without intermediates. Below, on the base about fifteen weaker cords alternate with interstitial threadlets, except on the neck. The suture, on early spire whorls, is above the lower peripheral row of nodules but descend below it on the last two and a-half whorls. Outer lip broken, but aperture and canal apparently much as in A. maoria. ….
Height (minus early whorls), 37 mm.; diameter, 22 mm.
Locality: N166/539, G.S. 5360. Pahaoa River, near Ngakonui, Basal Tongaporutuan.
A zealta has the spire higher, the anterior angle and tuberculate cord obsolete, and all spirals on the base fine and equal in strength.
Vexillitra marwicki n.sp (Pl 26, fig. 16.)
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Small, ovate-fusiform, glossy. Protoconch of 1 1/2 smooth whorls followed by 4 1/2 post-nuclear whorls. Shoulder narrower than in V. fracta Marwick with
weaker moniliform girdle on the shoulder angle. Thirteen strong rounded axial ribs a whorl, from suture to suture, obsolete on the latter part of the body whorl of most specimens. Sides of whorls not vertical as in fracta, but expanding below the shoulder. Body whorl convex, expanding from the shoulder to the suture level then contracting rapidly.
Height, 6.4 mm.; diameter, 3.2 mm.
Locality: N165/507, Bell's Creek, Middle Tongaporutuan.
Vexillitra wainuioruensis n.sp. (Pl. 26, fig. 15.)
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Small, biconic, rather thin, glossy. Six whorls including protoconch of 1 1/2 whorls. Early post-nuclear whorls have broad, low, rounded, vertical axial ribs (24 on second post-nuclear whorl) which became obsolete on later whorls, hardly discernible on the penultimate and lacking on the body whorl. Shoulder, level, narrow; peripheral girdle weak, at first moniliform, but becoming smooth as the axials weaken. Body whorl descending nearly vertically from the peripheral girdle then contracting rapidly to the canal.
Height, 6.1 mm.; diameter, 3.4 mm.
Locality: N166/535, lower Wainuioru River, uppermost beds of Hurupi Formation, Basal Tongaporutuan, unique holotype.
V. marwicki n.sp. is readily distinguished by the fewer and stronger axials, and the sloping sides of the whorls. V. fracta Marw. has 16 axials per whorl, very much weaker than on marwicki, and has about 5 obsolete spiral grooves on the body whorl.
Neocola aff. demissus Marwick.
The specimens from Wairarapa are shorter and broader than the type. The suture is at about the same height, but the shoulder is less concave and less steeply inclined, so that the whorl is relatively wider. The sculpture is more prickly but the type and paratypes of demissus are somewhat worn. The axials are a little stronger on the base and the spirals are less regular and heavier. The anterior canal appears to be more strongly twisted, but this is not certain because this part is more or less damaged in all the Wairarapa specimens.
Locality: N162/604, south branch of Whakatahine Stream, west of Brocken Range, about upper Clifdenian or Lilburnian.
In the Altonian beds west of the Brocken Range and at Ngahape, two other species of Neocola are present. The specimens are too poorly preserved to be determined precisely, but one species appears to be like N. apudalpha Finlay, and the other is close to both N. alpha Fin. and N. beta Fin.
Baryspira macbeathi n.sp. (Pl. 26, fig. 11.)
Allied to B. robusta Marw., differing in details of callus and aperture. Spire about half height of aperture, conical with nucleus visible through the tip. Body whorl marked off from spire by a rounded but distinct angle below which the sides are gently convex. Apertural callus thick, extending about half way round shell, with its lower edge nearly horizontal, a short distance above spiral depressed band, and top just below the apex Columella gently concave, not recurved at the
top; fasciole bearing a single strong groove near the top; aperture oval, produced above as a broad shallow groove in the callus.
Height, 35 mm.; diameter, 17 mm.
Localities: N162/503, Hurupi Formation, lower Wainuioru Valley, basal Tongaporutuan (holotype); N166/538, Hurupi Formation, Pahaoa River east of Ngakonui Homestead, basal Tongaporutuan (one complete paratype). Many broken specimens, lacking the body whorl, were collected from several localities in the Hurupi Formation.
The species is named in honour of Mr. D. M. MacBeath, who collected the holotype. The writer is grateful to Mr. O. P. Olson for discussion about this species.
B. macbeathi bears a close superficial resemblance to the following species, but differs in details of the columella and fasciole.
Baryspira n.sp. aff. mucronata (Sowerby).
This species has a heavier callus than mucronata, and the outline is similar to that of B. macbeathi. It is abundant together with mucronata at many lower and middle Nukumaruan localities in south-east Wairarapa, and the two forms seem to intergrade at some places. Mr. Olson has already recognised the form from the Nukumaruan of Hawke's Bay and will describe it elsewhere.
Conospirus brockenensis n.sp. (Pl. 26, fig. 14.)
Shell small for the genus. Protoconch: 5 surviving whorls (the tip, probably about one whorl, broken off), conic, tall, making the spire outline very concave. 5 1/2 post-nuclear whorls, staged, with well-developed peripheral keel bearing about 20 weak nodules a whorl, with 3 weak spiral threads crossing the nodules. Suture close below the keel; a weak subsutural fold; shoulder otherwise nearly horizontal. Spire including protoconch about 1/3 the height of the aperture. Body whorl: conic, sides straight posteriorly, concave anteriorly, so that the neck is somewhat attenuated; spaced, linear, spiral grooves cover the body whorl from the neck where they are strongest, nearly to the peripheral keel. Aperture long, narrow, with parallel sides.
Height, 18 mm.; diameter, about 7 mm. (Holotype, with tip of canal missing).
Locality: N162/604, middle Te Wharau Formation, south branch of Whakatahine Stream, upper Clifdenian or Lilburnian. Unique holotype.
The protoconch is distinctive but unfortunately the upper three whorls were damaged after illustration. The sculpture is sufficiently diagnostic to establish the species.
Conospirus cf. rivertonensis Finlay.
Some Wairarapa shells with convex spire outline seem inseparable from rivertonensis. Other Wairarapa specimens differ only in their concave spire outline and have been referred to C. cf. oliveri Marwick. The specimens are all poorly preserved and possibly represent a single species.
Localities: Several localities in the Altonian beds south of Ngahape and west of the Brocken Range, and in the Clifdenian or Lilburnian beds in the Kuamahanga Syncline.
Bathytoma wairarapaensis n.sp. (Pl. 25, fig. 5.)
Shell of moderate size. Spire probably less than the height of the aperture plus canal. Protoconch and early whorls missing. Suture just below peripheral keel, descending on latest whorls. A single narrow, moniliform subsutural cord, the gemmules elongated transverse to the cord, in places extending up to the suture, causing it to be finely crenulated. Shoulder narrow, deeply concave, bearing numerous fine irregular spiral threads. On the peripheral keel a single raised cord ornamented with about 32 gemmules a whorl, elongated parallel to the cord. Below the periphery, early spire whorls carry a weakly gemmate cord; a second slightly stronger cord appears on later spire whorls as the suture descends. On the body whorl, 6 widely spaced narrow gemmulate cords with 6 to 8 fine irregular threads between each pair. On the neck at least 8 more closely spaced but weaker cords with irregular gemmules and a few irregular intermediate threads. The tip of the neck is broken off.
Height, 27 mm.; diameter, 15·5 mm.
Locality: N162/604, Middle Te Wharau beds, south branch of Whakatahine Stream, upper Clifdenian or Lilburnian (holotype and 1 juvenile paratype).
Since the protoconch has not been seen, the generic location is provisional It seems to be related to B. mitchelsoni Powell which differs in having the suture immediately below the periphery in all whorls, the peripheral cord double, the body whorl less inflated contracting below the keel, whereas in wairarapaensis the body whorl is at first cylindrical, then contracts rapidly. The two species also differ in minor details of the ornament.
Of moderate size, narrowly biconic, spire slightly higher than aperture plus canal. Protoconch small, dome-shaped, of 1 1/2 smooth whorls. 6 post-nuclear whorls regularly increasing in size. Sculpture, peripheral keel with 16 to 17 strong nodules; subsutural cord with an equal number of nodules, about half the size and slightly in front of the peripheral nodules. Shoulder narrow, concave, with 2 weak spiral threads. Body whorl, below the periphery, with 3 strong spaced gemmate cords, with single interstitial threads, followed by 6 fine threads on the neck; the 3 strong moniliform cords are present in all paratypes, but the finer sculpture on the body whorl is variable.
Height, 13 mm.; diameter, 6 mm.
Localities: N165/508, N165/507 (holotype), Bell's Creek, middle Tongaporutuan. This species is not closely related to other described species of Micantapex.
Micantapex murdochi prior n.subsp. (Pl. 26, fig. 12.)
Differs from murdochi chiefly in having larger and fewer peripheral nodules: holotype and one paratype 16, one paratype 15 and one paratype 14 nodules per whorl. Keel closer to the lower suture than in murdochi. Sub-sutural cord weak, with numerous weak nodules. Base and upper part of neck, with 9 spaced, narrow, raised cords, 1 intermediate between the fifth and sixth counted from above; 7 finer closer cords on lower part of neck, and fasciole.
Height, 20 mm., diameter, 9 mm.
Locality: N162/717. Blue-grey, silts immediately below shell limestone, Wheraiti Hill, on Te Wheraiti-Fernyhurst Road, top of Pelicaria acuminata zone (lower Nukumaruan); holotype and 3 paratypes.
This form may merit specific separation, but as yet only four specimens are known. It is very similar to murdochi in general appearance, but the differences seen on closer inspection are constant. The new subspecies seems to be intermediate in some characters between murdochi and proavitus Powell, having the narrow, weakly nodulous sub-sutural border of the latter, relatively fewer nodules on the keel, and the keel set lower on the whorl than on murdochi. No paratype has any trace of interstitial spiral sculpture such as is typical of murdochi and proavitus.
Type (by original designation): Surcula oamarutica Suter (= Drillia fusiformis Hutt.).
Powell (1942, p. 57) described the protoconch of Comitas as “two-whorled, papillate, smooth”. Finlay, on the contrary, in his original description (1926, p. 251) stated that “the genotype has a two-whorled papillate apex … the latest whorl developing a strong but not sharp carina”. The keel can be seen clearly on specimens from Target Gully and Owamoa. On C. onokeana King, apparently a direct descendant of fusiformis, the protoconch is larger, more depressed, and has a much sharper keel, commencing near the middle at the beginning of the second whorl and descending close to the lower suture. On the following species the protoconch is smaller than but otherwise similar to that of onokeana.
Comitas terrisae n.sp. (Pl. 27, figs. 24, 25.)
Similar to fusiformis but smaller; 6 post-nuclear whorls, staged, angled at about 3/4 the height on the last 3 whorls. Spiral sculpture: 2 broad low cords with almost linear interspace crossing the axials half way between sutures; on the third whorl 2 weaker spirals appear, one above and the other below the 2 cords, and on the sixth whorl a further weak thread appears from beneath the descending suture. On the body whorl, below the 2 main cords, 5 narrow, spaced, spiral cords reach half way across the base; remainder of base and the neck are covered with dense fine threads. Shoulder narrow, concave, with a relatively deep U-shaped sinus.
Height, 20.5 mm; diameter, 7.5 mm.
Locality: N165/507 Bell's Creek, middle Tongaporutuan (holotype and 3 paratypes).
Marshallena curtata (Marwick).
1926, Turricula curtata Marwick. Trans. N.Z. Inst., 56, p. 325, Pl. 74, fig. 8.
Several specimens, closely matching the holotype, were collected from the middle Tongaporutuan beds of Bell's Creek (N165/507).
Splendrillia whangaimoana n.sp. (Pl. 27, fig. 22.)
Closest to the Opoitian afflicta (Marw.), but shorter and broader; whorls angled at the same height, each with 9 to 10 axials. Subsutural cord narrow, distinct, weaker in some paratypes. Peripheral angle more acute than in afflicta, axial raised to moderately sharp nodules, tapering off rapidly below. On a paratype the lower parts of the axials are obsolete on the latter part of the body
whorl, thus producing the type of sculpture characteristic of S. clava Pow. Shoulder deeply concave and smooth except for growth lines; below periphery numerous very fine spiral striae, strongest on base and neck. Base contracted rapidly, neck and anterior canal narrower and longer than usual in Splendrillia.
Height, 14·3 mm.; diameter, 6·1 mm.
Locality: N165/563. Cliffs between Whangaimoana and Lake Ferry, Palliser Bay, upper Waitotaran.
Splendrillia clava differs in its blunter peripheral angle, lower on whorls, shorter axials and weaker spiral striae.
Splendrillia n.sp aff. powelli King.
Two damaged specimens from N165/507, Bell's Creek, middle Tongaporutuan. have the heavy sub-sutural fold and distant linear spiral grooves of powelli. but are much broader and more strongly angled at the periphery.
Genus Wairarapa n.gen.
Type species Wairarapa rebecca n.sp.
This genus is proposed for shells superficially resembling Splendrillia but differing in protoconch, sub-sutural fold, and “stromboid notch”. Shell small with a depressed dome-shaped protoconch of 1 1/2 smooth glossy whorls, the tip large, flattened and eccentric. Ornament of broad, rounded folds extending downwards across the base and upwards on to the subsutural fold, though interrupted at the deeply concave shoulder; subsutural fold strikingly broad, rounded and swollen, but no other spiral sculpture present. Judged from the growth lines the posterior sinus is moderately deep, U-shaped, with its apex on the lower part of the shoulder, and there is no stromboid notch at the base of the outer lip. Parietal callus pad thick. Anterior canal moderately short, shallowly notched.
The peculiar sub-sutural fold is most nearly paralleled in the recent Central American Crassispira erebus Pilsbry and Lowe and in the Australian recent Melatoma dupliaris Hedley. C. erebus is a moderately large shell (holotype 24·2 mm.) with the nucleus typical of the genus, while M. dupliaris is small (8 mm.) comparable in size to Wairarapa and possessing a protoconch described by Hedley simply as two whorled. Judged from the type figures erebus and dupliaris are very similar to each other, except for the size, and for the fact that the anterior fasciole of erebus is somewhat more convex. Wairarapa differs from both in possessing a broader more depressed nucleus of fewer whorls, broader, more rounded axials and a more concave shoulder, and in lacking spiral sculpture.
Wairarapa rebecca n.sp. (Pl. 27, fig. 20.)
Small, solid, narrowly ovate; spire 1 1/2 times the aperture plus canal. Ten broadly rounded axial folds on body whorl, tapering downwards, oblique, curving backwards on the lower part of the base. Other details described in the generic diagnosis above.
Height, 7.7 mm.; diameter, 3.4 mm.
Locality: N165/507, Bell's Creek, middle Tongaporutuan (Holotype and one paratype).
The paratype of Wairarapa rebecca has the axials on successive whorls staggered, not in line as on the holotype, but this is probably due to damage during growth.
Pseudoinquisitor flemingi n.sp. (Pl. 27, fig. 19.)
Shell elevated with spire 1 1/2 times the height of the aperture plus canal, but rather stout for this genus; canal constricted, rather long. Judged from the growth lines, posterior sinus moderately deep and U-shaped, occupying the whole of the shoulder below a strong sub-sutural keel. Nucleus worn on the type, but on paratypes consisting of 1 1/2 smooth elevated whorls followed by 1/4 whorl with weak flexuous axial ribs or varices concave to the left. Six post-nuclear whorls, regularly increasing, strongly angled at the middle, with a moderately broad, concave shoulder. Axials 9 on early whorls, 11 on body, slightly oblique, broad, high, rounded, extending from just above the peripheral angle across the base nearly to the neck. Spirals, on spire whorls, below angle, three broad low cords with narrow interspaces strongest on the axial ribs; on body whorl, 18 rather weak cords covering base and neck. Shoulder smooth.
Height, 16·3 mm.; diameter, 6·4 mm.
Locality: N165/507, Bell's Creek, middle Tongaporutuan.
Some paratypes have stronger spirals. This is fairly certainly not a true Pseudoinquisitor since not only is the nucleus discrepant, but also the whorl shape and general outline of the shell differ somewhat from those of the genotype, Pseudoinquisitor problematicus Powell. Moreover, the heavy sub-sutural keel shows that it does not belong in Integradrillia Powell or Vixinquisitor Powell.
A paucispiral protoconch with a few brephic axials on the latest portion seems to be characteristic of a number of closely related clavine shells, which also generally have the stromboid notch at the base of the outer lip either weak or absent—e.g., Integradrillia, Vixinquisitor both of Powell, Crassispira Swainson and its subgenus Crassispirella Bartsch and Rehder, Carinodrillia Dall probably Clathrodrillia Dall, and Compsodrillia Woodring. Of these Carinodrillia appears to be closest to Pseudoinquisitor flemingi n.sp., the chief difference apparently being the very much weaker spiral sculpture of the new species. Its nucleus, broad, smooth shoulder, and constricted anterior canal, on the other hand, are all paralleled in Carinodrillia.
The location of the species in Pseudoinquisitor is therefore provisional, but it is not desired to create a new genus or record a further foreign genus in New Zealand without more research into the matter.
Genus Maoricrassus n.gen.
Type Species: Maoricrassus carinatus n.sp.
This name is proposed for another clavine group represented at Bell's Creek, possessing a paucispiral protoconch with weak axials on the latest portion, and a very weak or absent stromboid notch. More specifically the protoconch consists of 1 1/2 whorls, the tip smooth, fairly small, somewhat flattened, later portion with dense, very fine spirals visible only under a microscope, the last fraction of a whorl with 4 thin, closely spaced axials concave to the left. Post-nuclear whorls with strong peripheral angle commencing near the lower suture rising to a little below the middle by the third whorl. Shoulder gently concave with a very weak
sub-sutural fold. Body whorl broadly angled on the base, contracting rapidly below the angle to a moderately long tapered columella. Judged from growth lines, sinus moderately deep, U-shaped, occupying most of the shoulder, and stromboid notch not present. Sculpture, brephic axials slightly arcuate, concave to the left, reaching both sutures but widest and highest at the peripheral carina where from the beginning they are rendered slightly tuberculate by a narrow spiral cord; axials stopped at the sub-sutural fold on third whorl and hardly encroaching on the shoulder on the body whorl where they extend downwards to just below the basal angle. Spirals consist of low rounded distant cords crossing the axial ribs and interspaces; some distant threads on the neck and anterior fasciole. Shoulder smooth except for growth lines, which are faint over most of shell, raised to weak ridges on the anterior fasciole.
This genus appears to be related to the group discussed under the heading of Pseudoinquisitor flemingi n.sp., but is distinguished by the basal angle.
Maoricrassus carinatus n.sp (Pl. 27, fig. 21.)
Small, with pagodiform spire about 1 1/2 times the height of the aperture plus canal; 6 whorls including protoconch. Sculpture, 11 strong, straight, oblique axial folds rather sharply crested and tuberculate at the peripheral keel. Two obscure spiral cords appear below the keel on penultimate whorl, the lowest immediately above the suture. On body whorl 4 distant cords below the peripheral keel the third from above situated on the base angle and the strongest.
On remainder of base and neck 8 fine widely spaced threads, closer on neck. Inner lip thin bounded by an incised line, without a callus pad beside the posterior sinus.
Height, 6·3 mm.; diameter, 3·3 mm.
Locality: N165/507, Bell's Creek, middle Tongaporutuan; (holotype and one paratype consisting of spire whorls only).
The paratype has the spirals better developed, the first below the periphery appearing on the penepenultimate whorl.
Awateria miocenica n.sp. (Pl. 27, fig. 28.)
Similar in outline to A. streptophora Suter, but larger, narrower, with longer anterior canal. Spire lightly convex in outline, a little higher than aperture plus canal. Protoconch and earliest whorls missing in all specimens; 5 whorls preserved in holotype. Subsutural cord strong, not moniliform, bearing a spiral groove which is not present in some paratypes. Shoulder narrow, with 2 spiral cords with linear interspace. Axial ribs narrow, sharply crested but not high, slightly oblique, 11 a whorl, on body tapering over base and dying out before reaching the neck. Spiral sculpture, on spire whorls 3 flattened cords with equal interspaces, each with a weak interstitial thread; on body whorl 18 cords, narrower and more rounded on base and neck, lowest 8 closer spaced and without interstitials. Growth lines prominent over entire shell.
Height, 11·4 mm.; diameter, 5·2 mm.
Locality: N165/507, Bell's Creek, middle Tongaporutuan (holotype and 14 paratypes).
Awateria striata n.sp. (Pl. 25, fig. 2.)
Closely related to A. miocenica n.sp., but broader, with less elevated spire, and less prominent sub-sutural keel. 11 axials on penultimate whorl, 12 on body.
2 spiral threads on sub-sutural keel, 3 linear grooves on shoulder, on penultimate whorl 8 linear grooves below peripheral angle; on body 12 linear grooves below periphery, followed below by about 18 low, rounded, irregular, closely spaced cords on the lower part of base and the neck.
Height, 10·7 mm.; diameter, 5 mm.
Locality: N165/508, Bell's Creek, middle Tongaporutuan (holotype and 2 paratypes).
Awateria miocenica and A. striata have not been collected from the same horizon. N165/507 is stratigraphically about 200 feet higher than N165/508.
Several species of Awateria differ from the typical series in that the subsutural keel though massive, is not prominently moniliform. This group, which includes A. miocenica n.sp., A. striata n.sp, A. retiolata King, A. wairoaensis Powell, and probably A. mollyae King may be worth separation as a sub-genus of Awateria
Subgenus Mioawateria n. subg.
Type species: Awateria personata Powell 1942, p. 130, Pl. 11, fig. 3. Opoitian (lower Pliocene) Wairoa S.D.
Powell noted that personata is not typical of Awateria. The features distinguishing it from Awateria s s. are the strong peripheral angle, bearing a narrow tuberculate girdle, wide, flattened, gently sloping shoulder, narrow moniliform sub-sutural fold and relatively long anterior canal.
Besides personata the new sub-genus will include the Altonian A. experta Laws, A expalliata Laws, and A. n.sp. of Laws (1947, pp. 538, 539), A. (M) pahaoacnsis n. sp. from the lower Tongaporutuan, and A. karakaensis Marwick, from the Opoitian.
Awateria (Mioawateria) pahaoaensis n.sp. (Pl. 26, fig. 18.)
Size average for the group, spire slightly higher than aperture plus canal. Axials very oblique, narrow, sharply crested, raised to sharp small tubercles on the peripheral keel, crossing the shoulder weakly and arcuately, producing small, obliquely elongated nodules on the narrow sub-sutural fold. Spirals, none on the shoulder; a sharp narrow cord accents the peripheral keel; spaced linear grooves below the keel, 5 on the penultimate, 3 very indistinct on the antepenultimate. On the body whorl the axials are strongly flexuous, reaching on to the neck, but become obsolete on the later portion; about 22 spirals on the base and neck. Shoulder wide, flat to concave, fairly steeply sloping. Anterior canal short and broad. The protoconch is dome-shaped of 1 1/2 or slightly more whorls, the tip a little eccentric, smooth except for the last quarter whorl, which has five closely spaced, faint axial ribs or varices slightly concave to the left.
Height, 8.3 mm; diameter, 4·1 mm.
Locality: N166/511, uppermost beds of the Hurupi Formation (lower Tongaporutuan) Pahaoa River cliffs N.W. of Ngakonui homestead. Unique holotype.
Genus Mangaoparia n.gen.
Type species: Mangaoparia powelli n. sp.
Diagnosis: Protoconch paucispiral, consisting of little more than one whorl, smooth and glossy, the tip large, eccentric, a little flattened. Shell small, rather stout, strongly angled with a moderately wide sloping shoulder. Sub-sutural fold
narrow, better defined on early whorls, undulating over axials of previous whorl on adult part of shell. Brephic sculpture of axials without spirals, at first broad and rounded, becoming narrow, sharply crested and very widely spaced on later whorls. Whorl angle at first rounded, becoming sharp by about the third whorl where it begins to develop a very weak spiral girdle similar to that of Vexillitra Marwick, which forms small sharp tubercles at the intersections with the axials. The axials diminish across the shoulder, not reaching the sub-sutural fold, and, on the type species, taper downwards, reaching almost on to the fasciole. Spiral sculpture is absent from the shoulder, weak immediately below the whorl angle and on the neck, stronger on the base, consisting of a few distant, low, broad, rounded cords. Sinus, judged from the growth lines, on the lower part of the shoulder, very shallow. Anterior canal short, inner lip very thin, with ill-defined boundary.
Mangaoparia is doubtfully located in the Borsoniinae, close to Awateria The posterior sinus is very similar to that of Awateria, and excepting the sub-sutural fold, the sculpture is not very different from the species A. marwicki Powell, and A. defossa Powell. The lack of the moniliform sub-sutural fold, and the very wide spacing of the axials, however, show that Mangaoparia is widely divergent from Awateria.
Relationship to Guraleus is a second possibility, for the form and sculpture of Mangaoparia approach (though not closely) those of the Australian shells G. flavescens (Angas), G. singletoni Powell, and G. adelaidensis Powell.
Mangaoparia powelli n.sp. (Pl. 27, figs. 26, 27.)
Most details described in the generic diagnosis above. Spire about 1 1/2 times the height of the aperture and canal. Post-nuclear whorls 4 1/2. Axials 9 per whorl, vertical, narrow, on penultimate whorl and body roughly in line. On body whorl 2 broad low cords, hardly discernible, below keel, 4 narrower and more distinct on the base, below the suture level. Neck with 3 or 4 microscopic cords.
Height, 5.3 mm.; diameter, 2.9 mm.
Locality: N165/507, Bell's Creek, middle Tongaporutuan (holotype and 2 paratypes) (Bell's Creek is a small tributary of Mangaopari Stream).
Antiguraleus rishworthi n. sp. (Pl. 26, fig. 13.)
Very small, short and broad, spire slightly higher than the aperture plus canal. Strong peripheral carina below a gently sloping very lightly concave shoulder. Axials narrow, moderately high, sharply crested, distant, vertical, 10 on body whorl extending on to neck. Spirals, 5 or 6 very fine threads on the shoulder; a strong cord on the periphery rendering axials tuberculate; a second primary cord mid-way between the keel and the lower suture on spire whorls, forming weak tubercles at the intersections with the axials; 6 more primary cords below the suture level, on the body whorl, becoming weaker on the neck and fasciole; mid-way between each pair of primaries a secondary cord, and in each interspace a tertiary very fine thread. Sinus on the shoulder, U-shaped shallow, but deep for the genus; outer lip broken, but growth-lines showing a slight indentation as though indicating a “stromboid notch”. Anterior canal short, broad. Protoconch of 1 1/2 smooth glossy whorls, the tip small and slightly eccentric.
Height, 4·8 mm.; diameter, 2·9 mm.
Locality: N165/507, Bell's Creek, middle Tongaporutuan. Unique holotype.
This species is placed in Antiguraleus because of its paucispiral protoconch and guraleoid sculpture. The protoconch is not quite typical, however, and the possible “stromboid” notch and not very shallow sub-sutural sinus suggest that the shell might be more correctly located in the Clavinae.
Antiguraleus makaraensis n. sp. (Pl. 25, fig. 4.)
Related to the Petane species abnormis (Hutton), this shell differs in being much narrower, having the whorls less depressed and the spire a good deal higher than the aperture and canal. Axials, 9 on the body whorl, consisting of broad rounded strong folds, with narrow interspaces, extending down to the top of the neck. Two strong primary spirals on early whorls, three on penultimate, the uppermost on the periphery; strong interstitial threads between the cords, with a fine thread appearing on either side of the upper interstitial on the last two whorls. On the body whorl, besides the spirals already described, are four primary cords with interstitials followed below by 10 to 12 fine cords with linear interspaces. Shoulder with 7 or 8 microscopic threads, lightly convex. Anterior canal short, broad, straight.
Height, 7 mm.; diameter, 3·1 mm.
Locality: N165/515, Makara River, Pelicaria acuminata Zone (lower Nukumaruan). Unique holotype.
Neoguraleus hautotaraensis n.sp. (Pl. 27, fig. 23.)
Similar to N. finlayi Powell, narrow with elevated spire. Smaller than finlayi, lacking the flattened border to the suture, having fewer axials, 10 on the penultimate, 11 on the body whorl (14 and 15 on finlayi). The axials seem to be broader and higher and extend up quite to the suture. Spirals strong in the axial interspaces but very weakly crossing the axial ribs; 5 moderate cords with narrower interspaces on later spire whorls, obsolescent on latter half of body whorl; a few weak obscure cords on the neck.
Height, 6 mm.; diameter, 2·4 mm.
Locality: N165/520, Hautotara Bridge, Awhea Road, Pelicaria convexa Zone (upper Nukumaruan). Unique holotype.
List of References
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Dell, R. K., 1952. A Revision of the Molluscan Fauna of the Hurupi Beds, Southern Wairarapa. Dominion Mus. Rec. in Zool. 8: 71–86.
Finlay, H. J., 1926. New Shells from New Zealand Tertiary Beds, pt. 2. Trans. N.Z. Inst., 56: 227–258.
Fleming, C. A., 1944. Molluscan Evidence of Pliocene Climatic Change in New Zealand. Trans. Roy. Soc. N.Z. 74 (3): 207–220.
King, L. C., 1933. Tertiary Molluscan Faunas from the Southern Wairarapa. Trans. N.Z. Inst. 63: 334–354.
Laws, C. R., 1939. The Molluscan Faunule at Pakaurangi Point, Kaipara No. 1. Trans. Roy. Soc. N.Z. 68: 466–503.
Macbeath, D. M., 1950. Geology of an Area North-East of Martinborough, East Wairarapa. University of N.Z. M.Sc. Thesis, lodged in Victoria University College library, Wellington.
Marwick, J., 1926. New Tertiary Mollusca from North Taranaki. Trans. N.Z. Inst. 56: 317–331.
— 1931. The Tertiary Mollusca of the Gisborne District. N.Z. Geol. Surv. Pal. Bull. 13.
Powell, A. W. B., 1942. New Zealand Tertiary and Recent Mollusca of the Family Turridae. Auck. Inst. and Mus. Bull. 2.
Vella, P., 1949. The Geology of an Area South-East of Martinborough, East Wairarapa. Univ. of N.Z. M.Sc. Thesis lodged in Victoria University College library, Wellington.
— 1953. The Genus Pelicaria in the Tertiary of East Wairarapa. Trans. Roy. Soc. N.Z., 81 (1) pp. 34–48.
Woods, S. V., 1864. A Monograph of the Eocene Mollusca, or Descriptions of shells from the Older Tertiaries of England. Publication of the Palaeontographical Society.