Gast Athleta Lyria Cenozoico NZ Jrsnz2003

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The Volutid generaAthleta andLyria (Mollusca: Gastropoda)

in the New Zealand Cenozoic

Phillip A. Maxwell1

Journal of the Royal Society of New Zealand,Volume 33, Number 1, March 2003, pp 363394

1Bathgates Road, RD 10, Waimate, New Zealand. Email: [email protected]

R02035 Received 26 August 2002; accepted 24 December 2002; published 30 April 2003

Abstract New Zealand Cenozoic records of the warm-water volutid generaAthleta

andLyria are reviewed. Six species ofAthleta in two species-groups are recognised:A.

lata (probably Waipawan or Mangaorapan, Early Eocene),Athleta n. sp. A (Mangaorapan

(?), late Porangan or early Bortonian, Middle Eocene);A. necopinata (Bortonian),A.

marwicki n. sp. (Bortonian), A. taikoensis n. sp. (Mangaorapan to late Porangan orearliest Bortonian), and A. mimica n. sp. (Bortonian). Most species have a short

recorded stratigraphic range and are therefore potentially useful for zonation.Athleta is

not known after the Bortonian in New Zealand, and may have become locally extinct in

response to a cooling episode. Volutospina (Athleta) huttonipseudorarispina is

synonymised with V. (Athleta) huttoni (both Altonian, Early Miocene). V. huttoni and

other large Neogene volutes currently assigned to Mauira are transferred toAlcithoe.

Athleta (Athleta) wangerrip (Paleocene, Victoria) is transferred to the subgenus

Ternivoluta. The earliest records ofLyria from New Zealand are specifically

indeterminate juvenile shells (probably representing two species) from Otaian and

Altonian (Early Miocene) horizons at Parengarenga Harbour, Northland. The best-

known New Zealand species, L. zelandica is recorded only from the Long BeachShellbed (Altonian), Clifden Section, Waiau River, Southland. Specimens from the

Lillburnian (Middle Miocene) at Clifden and Fox River, Westland (Waiauan, Middle

Miocene) apparently represent a related, undescribed species. The youngest record of

the genus is L. n. sp. (?) aff. L. nucleus from Kaawa Creek, south-west Auckland

(Opoitian, Early Pliocene).

Keywords New Zealand; Australia; Eocene stratigraphy; Cenozoic Mollusca; Gastropoda; Volutidae; Athleta;

Lyria; new species; new records; new synonymy; biogeography; paleoclimates

INTRODUCTION

Volutes have been present in the New Zealand region since at least the Late Paleocene, andhave been an important component of shallow marine molluscan assemblages from the Early

Eocene onwards. However, most of the numerous nominal species that have been described

to date are members of one subfamily, the Zidoninae, and, more narrowly, one tribe, the

Alcithoini. About 120 nominal species-group taxa distributed among 13 genus-group taxa

have been proposed for New Zealand zidonines, and although some of these have been

synonymised by later workers, not all of this rationalisation is justified (particularly at the

supraspecific level), and much work needs to be done before a satisfactory classification of


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364 Journal of the Royal Society of New Zealand, Volume 33, 2003

the subfamily can be developed. In contrast, other volutid subfamilies are poorly represented

in New Zealand. Beu & Maxwell (1990) pointed out that Pakaurangia Finlay, 1926 is an

earlier name for the deep-water volute genus long known as Teramachia Kuroda, 1931, and

placed it in the Calliotectinae which they classed as a subfamily of Turbinellidae. Bouchet &

Poppe (1995) have since shown thatPakaurangia is in turn a junior synonym ofCalliotectum

Dall, 1890 and returned Calliotectinae to the Volutidae. They briefly discussed the few NewZealand fossil records (all of Middle or Late Miocene age) of this characteristically bathyal

genus.

In this paper I discuss New Zealand records of the generaAthleta (Athletinae) andLyria

(Volutinae), which are of particular interest because they are thought to be warm-water

elements in the Cenozoic fauna. Both genera were formerly widespread but underwent range

restriction in the late Cenozoic. The review was prompted by the discovery that both genera

are far better represented in New Zealand than was previously thought. Of particular interest

is the presence of aLyria closely similar to the type species in the Early Pliocene at Kaawa

Creek. The only known specimen was discovered 60 years ago, and its documentation is

therefore somewhat overdue.

Volutid biogeography

Bouchet & Poppe (1988, pp. 24, 30) asserted volutes are amongst the the most holobenthic

of all gastropods, and that all modern and most fossil species have a protoconch indicating

intracapsular larval metamorphosis. Newly hatched juveniles are relatively large and incapable

of swimming. Although Bouchet & Poppe (1988) conceded that planktotrophy may have

persisted into the Paleogene in the Athletinae, they pointed that out some volute clades had

evolved non-planktotrophy as early as the Paleocene, and that this is the condition in all

Neogene (including Recent) volutes. This implies limited powers of dispersal, which is

consistent with the distribution of volutes at the present day. There are a few widespread

Indo-West Pacific genera, but most genus-group taxa in the family have (or had) a restrictedgeographic range.Athleta andLyria are exceptions to this generalisation. A. Beu (IGNS pers.

comm.) has pointed out that Provocator Watson, 1881 and Calliotectum are additional

exceptions. Provocator is represented in the modern New Zealand fauna by P. mirabilis

(Finlay, 1926) and is also recorded from southern South America and Kerguelen Island. It is

not known in New Zealand prior to the Late Pliocene. According to Weaver & du Pont

(1970),P. mirabilis has a small, conical protoconch of about whorls, which suggests it (or its

ancestor) arrived here as planktotrophic larvae from elsewhere in the southern ocean. Recent

Calliotectum species are recorded from the Indo-West Pacific, south-west Pacific, Caribbean,

and Peru-Ecuador (Bouchet & Poppe 1995). The oldest fossil record is from the Clifdenian

(Middle Miocene) of New Zealand. Wherever known the protoconch is very small and ofmamillate-paucispiral form, indicating non-planktotrophic larval development (Bouchet &

Poppe 1995; pers. obs.) The wide distribution ofCalliotectum was probably achieved when

the genus still had planktotrophic larval development.

Distribution ofAthleta

Athleta (in the broad sense of Darragh 1971) is one of the most widely distributed volute

genera, both geographically and stratigraphically. It is first recorded from the Late Cretaceous

(Darragh 1971) and its wide distribution has been attributed to the fact that most Paleogene

species seem to have had planktic larvae (Fischer et al. 1964; Darragh 1971, 1989; Hansen

1978).Athleta was particularly widespread in the Paleocene and Eocene when it was present

in North America, Europe, West Africa, India, Burma, Indonesia, Australia, and New

Zealand. Its range constricted during the Neogene but it persisted into the Miocene in Europe


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MaxwellAthleta andLyria in the New Zealand Cenozoic 365

Fig. 1, 2 Athleta sp. indet. TM 8241, IGNS (height of complete shell = 4 mm, protoconch diameter= 1.1 mm); GS 11650, South Branch, Waihao River near Pentland Hills (Waipawan or Mangaorapan).

and to the present day in southern Africa (Rehder 1969, 1974) and eastern Australia (Darragh

1971). (Rehder assigned the extant African species to Volutocorbis, which was regarded by

Darragh (1971, 1979) as a synonym ofAthleta.) Benthic larval development had evolved bythe Late Eocene in Australian species; the only one with a protoconch morphology indicating

a planktic mode of life is the PaleoceneAthleta wangerrip Darragh, 1971.

Where known the protoconch in New ZealandAthleta species is small (diameter ~1 mm)

and narrowly dome-shaped of about three whorls (Fig. 1, 2). The protoconch nucleus (the

first-formed portion) is very small, probably indicating that they had planktotrophic rather

than lecithotrophic larval development. However, despite their apparent capability for long-

range dispersal they do not closely resemble other Paleogene athletines, nor, for that matter,

any of the Australian fossil species discussed by Darragh (1971). One newly described

species,A. mimica, is remarkably similar to the (Miocene) type species of the genus in callus

development and sculpture, but as they differ in important columellar and siphonal charactersthe similarity probably results from convergence.

The oldest occurrences ofAthleta from New Zealand are from the Early Eocene, an

exceptionally warm period notable for the earliest local records of many warm-water groups

apparently derived from the north (see below). This suggests the closest relatives of New

Zealand athletines probably lived in central or southern Tethys, but representatives of the

subfamily recorded from this region are not closely similar to the New Zealand species.

Distribution ofLyria

Lyria is more widely distributed thanAthleta, with fossil records from North, Central, and

South America, Europe, Africa, south-east Asia, Indonesia, Australia, and New Zealand.

Modern species, however, are restricted to the tropical west Atlantic and Indo-West Pacific,

extending northwards to Taiwan and Japan, and southwards to south-west Australia, Victoria,


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northern Tasmania, Norfolk Island, and the Kermadec Islands (Weaver & du Pont 1970;

Darragh 1989; Bail 1993a,b). According to the scenario proposed by Darragh (1989), the

genus originated in the Late Cretaceous, probably in south-east Tethys, and had spread to

Europe and North America by the Paleocene, and to South America by the Late Eocene. The

earliest records ofLyria from Australia and New Zealand are from the Early Miocene, which,

if taken at face value, suggests that it took much longer for the genus to disperse to the south-west Pacific than to other areas. However, it may merely reflect the absence of suitable facies

of pre-Miocene age in the south-west Pacific; in particular,Lyria may well have been present

in Northland in the Paleogene, but molluscan faunules of this age from northern New

Zealand are invariably poorly preserved and/or of low diversity. Irrespective of whenLyria

reached New Zealand, the important point is that the oldest known local species, from the

Otaian (Early Miocene) of Parengarenga Harbour, Northland, has a dome-shaped protoconch

of about 3 whorls (Fig. 36), essentially similar to that in New ZealandAthleta species (but

having a larger, protruding nucleus), and also resembling the protoconch of the oldest known

Australian species,L. semiacuticostata Pritchard, 1896 (Longfordian, Early Miocene, Table

Cape, Tasmania) (Darragh 1989, fig. 1). A similar protoconch is present in L. zelandica

Finlay, 1924 (Altonian, Early Miocene) and Lyria n. sp. A (LillburnianWaiauan, Middle

Miocene) (Fig. 710).

In contrast, modernLyria species have a mammillate or bulbous protoconch (Bouchet &

Poppe 1988, fig. 1216; Bouchet & Bail 1991, fig. 3, 5) which, except for its relatively small

size, resembles those present in other extant volutids and probably indicates a similar non-

planktic larval stage. Despite this apparent impediment to dispersal, some Recent Lyria

species are separated by hundreds of kilometres of very deep water (~1000 m) from their

geographically closest congeners (Bouchet & Poppe 1988; Bouchet & Bail 1991). Bouchet &

Poppe (1988) raised the possibility of a short-lived demersal swimming stage in the

development of western PacificLyria species, sufficient to allow dispersal over distances of

200250 km, even though it is debatable whetherLyria larvae could survive in such deepwaters. (ModernLyria species typically live at depths of 100400 m (Bail 1993a).) Bouchet

& Bail (1991) recorded two species ofLyria from the Saya de Malha Bank in the south-west

Indian Ocean and suggested that they are descended from a species that had lecithotrophic,

demersal development.

The fact thatLyria had achieved a wide, probably pan-subtropical/tropical distribution by

the Late Oligocene or Early Miocene is difficult to explain except by dispersal of larvae able

to survive for at least moderately long periods in the plankton. The protoconchs ofLyria

zelandica, L. semiacuticostata, and the Parengarenga Lyria species are consistent with a

planktic larval stage in these species, and a similar protoconch seems to be present in some of

the Oligocene and Early MioceneLyria species from the south-eastern United States discussedby Hoerle & Vokes (1978). (The relatively large size of the protoconch nucleus in the New

Zealand species possibly indicates they had lecithotrophic rather than planktotrophic larval

development.) This implies that modernLyria species have been independently derived from

species with planktic larvae.

Fig. 310 Lyria species. Fig. 36Lyria sp. indet. Maxwell Collection (height of completeshell = 3.5 mm); MC/071, west side, Tahuna Channel, Parengarenga Harbour, Northland (Otaian,Early Miocene); Fig. 6 showing microsculpture on penultimate whorl of protoconch. Fig. 710 Lyrian. sp. A. Maxwell Collection; oyster bed, Cucullaea Point, Clifden Section (Lillburnian). Fig. 9, 10

Change in microsculpture on penultimate whorl of protoconch. Scale bars: Fig. 3, 7, 8 = 0.1 mm;Fig. 5, 6, 9, 10 = 10 m.


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Dispersal ofLyria to New Zealand was probably facilitated by island- or shoal-hopping

along ocean ridges, or may have been passive. Herzer (1998) argued that the tectonic

development of the Norfolk Ridge would have allowed one-way transport of terrestrial biota

from New Caledonia to New Zealand during Early to Middle Miocene, and the proposed

mechanism applies equally well to shallow-water marine organisms. (Lee et al. (2001) have

suggested that at least part of the New Zealand Cenozoic flora also arrived from NewCaledonia by this route.)Lyria is but one of numerous warm-water molluscan groups that

occur in the Early Miocene in Northland (see below). The lack of obvious close affinity

between Lyriazelandica and any of the Australian fossil species is evidence that it (or its

ancestor) arrived here from the north rather than across the Tasman. However, one of the

Early Miocene species from Northland resembles some of the Australian mid-Cenozoic

species, so trans-Tasman dispersal cannot be ruled out for this species.

The modern species Lyria nucleus (Lamarck, 1811) occurs off northern New South

Wales, Norfolk Island, and the Kermadec Islands (Weaver & du Pont 1970; Darragh 1989;

Wilson 1994), areas widely separated (~1400 km) from each other by deep ocean basins. A

closely similar form is present in the Early Pliocene of Kaawa Creek, northern New Zealand

(see below).L. nucleus resembles other extant species in having a protoconch of about 1.5

smooth, globose whorls (Weaver & du Pont 1970, p. 23), which makes it unlikely that its

highly disjunct distribution results from recent dispersal. It is suggested that these modern

populations have arisen independently from a species with planktotrophic larval development.

The Kaawa Creek species is a possible candidate for such an ancestor, but unfortunately the

only specimen lacks the apical whorls. If this scenario is correct the three modern populations

probably differ significantly from each other at the molecular level.

Abbreviations and conventions

AIM, Auckland Institute and Museum, Auckland; AUGD, Auckland University Geology

Department, Auckland; CM, Canterbury Museum, Christchurch; IGNS, Institute of Geological& Nuclear Sciences, Gracefield, Lower Hutt; OUGD, Otago University Geology Department,

Dunedin; AK 70424, Auckland Institute and Museum accession number; GS 11148, Institute

of Geological & Nuclear Sciences macrofossil collection number (formerly New Zealand

Geological Survey macrofossil collection number); J40/f8858, New Zealand Fossil Record

File number (derived from NZMS sheet number (J40), followed by the fossil collection

number); MC/008, Maxwell Collection number, Waimate; OU 7385, Otago University

Geology Department accession number; TM 4838, Institute of Geological & Nuclear Sciences

Type Mollusca registration number.

SYSTEMATICS

Superfamily Muricoidea Rafinesque, 1815

Family Volutidae Rafinesque, 1815

Subfamily Athletinae Pilsbry & Olsson, 1954

GenusAthletaConrad, 1853

Athleta Conrad, 1853: 448449. Type species (subsequent designation, Dall, 1890): Voluta

rarispina Lamarck, 1811; Miocene, France.

Notoplejona Marwick, 1926: 262, 270. Type species (original designation):Athletanecopinata

Suter, 1917; Middle Eocene, New Zealand.See Darragh (1971) for other subjective synonyms ofAthleta.


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DIAGNOSIS: Shell small for family, biconic to fusiform, spire depressed to moderately

elevated, gradate in many species. Protoconch conical to narrowly dome-shaped, or globose.

Teleoconch whorls subangled to strongly shouldered, last whorl elongate, weakly excavated

if at all; suture weakly impressed to channelled. Teleoconch sculpture variable, some species

cancellate with spiral and axial elements of equal strength, others with prominent axial costae

and/or peripheral tubercles and much weaker spiral elements, one species smooth. Aperturenarrowly pyriform to subrectangular; columella narrow to strongly padded, some species

with 3 or 4 subequal plaits, others with one plait and several much weaker ones, or almost

completely smooth. Parietal callus of variable strength, absent from some species, barely

developed in others, very thick in still others, even spreading onto previous whorls. Anterior

notch shallow to moderately deep, fasciole weakly to strongly developed; posterior notch

shallow to moderately deep. Outer lip thin or slightly thickened in some species, variciform

and denticulate in others.

See Darragh (1989) for anatomical characters.

DISCUSSION: Marwick (1926: 262) pointed out that Athletanecopinata differs from typical

species ofAthleta in having one strong anterior fold and several weak posterior ones, alloblique and situated on a pad in the adult; in having a spur on the outer lip opposite the upper

row of spines; and in the different disposition of the parietal callus pad. He noted that the

columella of immature specimens is like that ofPlejona [i.e., Voluta], but in the adult the

folds are situated on a thick pad of callus, and the outer lip is thickened, reflexed and

crenulated. From both [i.e.,Athleta and Voluta] it differs in having a double row of spines on

the whorls, as inNeoathleta, but it is distinguished from all these by the deep anterior notch

to the aperture, forming a well-defined fasciole much stronger than that ofAthleta. For these

reasons Marwick (1926) proposed the genus Notoplejona forAthleta necopinata and the

newly describedN. lata.

Wenz (1943) acceptedNotoplejona as a genus and placed it between Voluta andLyria,

and Pilsbry & Olsson (1954) included it in their newly proposed subfamily Lyriinae ratherthan in Athletinae which they introduced in the same paper. Darragh (1971), however, did

not consider the differences cited by Marwick (1926) to warrant segregation ofNotoplejona

fromAthleta. He consideredA. necopinata to be no more bizarre than some of the other

species assigned to the genus (including the type species A. rarispina), and, accordingly,

synonymisedNotoplejona (and several other genus-group taxa) withAthleta. However, the

differences between the New Zealand species on one hand, andAthletararispina and related

European species on the other, cannot be dismissed so lightly. All four of the New Zealand

species discussed here have reduced columellar plication compared withA. rarispina (Fig.

28),which has three narrow but distinct subequal and well-spaced folds. In addition, the New

Zealand species have a deeper anterior notch and, consequently, a more prominent fasciolethanA. rarispina. These differences are of a kind which have been used to distinguish genera

in other volutid subfamilies. One local species,Athleta mimica n. sp., is remarkably similar to

the much youngerA. rarispina in parietal callus development and axial sculpture, but differs

in the characters mentioned above; in particular, the columella is almost devoid of plaits.

The type species ofNeoathleta Bellardi, 1890,N. affinis (Brocchi, 1814) (Early Miocene,

Italy), resembles New Zealand Athleta species in having one moderately strong columellar

plait and several weaker ones above, and has a similar sculptural plan toA. taikoensis n. sp.

andA. mimica n. sp., but it has a thin outer lip, thinner parietal callus, and a much shallower

anterior notch, and is not closely related to the New Zealand species.

Cossmann (1906, 1909) recommended synonymisingNeoathleta, Volutocorbis Dall, 1890,and Volutospina Newton, 1906 withAthleta, claiming the differences between these nominal


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taxa relate mainly to minor sculptural characters. (Oddly enough, Cossmann & Pissarro

(1911, captions to pl. 4345) retained these taxa as subgenera ofAthleta.)

Darragh (1971) supported Cossmanns (1906) assessment and also proposed the merging

of several other genus-group taxa (includingNotoplejona) withAthleta. He admitted that the

type species,Athletararispina, is rather atypical because of its heavy parietal callus, thickened

outer lip, and tubercular sculpture, but claimed that because these characters have arisenindependently in other species several times throughout the geological history of the group

and in different lineages they have little supraspecific significance. Rehder (1974) attributed

considerable importance to the nature of the columellar plaits in Athletinae, and on this basis

disputed some of Darraghs (1971) conclusions; in particular he classed Notoplejona as a

subgenus ofVolutocorbis. Darragh (1979), however, cleaved to his earlier broad concept of

Athleta, and suggested that even ifVolutocorbis is recognised as a separate genus it should be

used only for the North American Paleogene species.

Darraghs (1971) comments imply that Athleta (as interpreted by him) is a large and

diverse genus with highly fluid character states. The alternative is thatAthleta is a polyphyletic

taxon, and that at least some of the clades involved are worth recognising at the subgeneric or

generic level: only a detailed phylogenetic study of the genus on a global scale can show

which of these interpretations is likely to be correct. In the meantime, I continue to place the

New Zealand species in Athleta, even though they clearly belong to a different group (or

groups) from the European, North American, and West African species. The resemblance of

A. mimica to Athleta rarispina, though striking, is superficial and does not extend to

columellar characters, and I interpret it as the result of convergence rather than an indication

of a particularly close relationship.

Darragh (1971) suggested that ifNotoplejona should eventually prove to be worth

segregating from Athleta, then Bendeluta Eames, 1957 is a possible synonym. The type

species ofBendeluta (Volutospina conicoturrita Newton, 1922; Late Eocene, Nigeria)

resemblesA. necopinata in having two rows of nodules on the last whorl, but differs in itsmuch more robust shell, and in having three prominent columellar folds and a much

shallower siphonal notch (Newton 1922), so these species are unlikely to be closely related.

Note on Australian Athletinae

Darragh (1971) distributed AustralianAthleta species among two subgenera,Athleta (s. str.)

and Ternivoluta Martens, 1897, and commented that the only significant differences between

these taxa are: (1) the protoconch in Ternivoluta is paucispiral and deviated, but turbinate or

dome-shaped with about three whorls in Athleta (s. str.); and (2) the outer lip is smooth in

Ternivoluta, but denticulate inAthleta (s. str.). The protoconch differences (indicating non-

planktic versus planktic larval development, respectively) are of a kind no longer regarded ashaving supraspecific significance. Apart from having a smooth outer lip, however, Ternivoluta

species differ from typicalAthleta species in having a much thinner outer lip, and a much

thinner parietal callus (little more than a smear in some species). Darragh (1971) assigned the

Late Paleocene Victorian speciesAthletawangerrip Darragh, 1971 toAthleta (s. str.) because

it has a turbinate protoconch, but in teleoconch characters, including callus development and

the nature of the outer lip, it is much closer to Ternivoluta species. Darragh (1971) pointed

out its similarity to the Late EoceneA. (Ternivoluta) curvicostata Darragh, 1971, and showed

these taxa as having a possible ancestor-descendant relationship (Darragh 1971, p. 183).A.

wangerrip is here assigned to Ternivoluta, which may warrant generic status when the

Athletinae are revised. It has to be pointed out, however, that the differences between

Ternivoluta andAthleta (s. str.) are arguably no more marked than those that have been used


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to justify other segregate taxa such as Volutocorbis, Neoathleta, and Notoplejona, all of

which are currently submerged underAthleta.

New Zealand records

Prior to this study only two species ofAthleta were known from New Zealand:A. necopinata,

which is relatively well represented in collections, and the much more poorly known taxonA.lata. Recent collecting, particularly from the Pareora Gorge section and other South Canterbury

sites, has shown the genus to be considerably more speciose, with six species represented in

the available material. Most of these species can be assigned to one or other of two distinct

groups that probably represent different clades. In one group, typified by A. necopinata, the

shell is elongate and the nodules in the upper (adapical) row are similar in strength or

stronger than those in the lower row. In the other group, which includesA. mimica n. sp., the

shell is biconic and the upper nodules are almost completely obsolete in adult specimens.

Columellar plaits are better developed in the former group.A. lata is intermediate between

the two groups in having a biconic shell, but the upper nodules seem originally to have been

at least as large as the lower ones, and it is included in the first group.At least three of the species are Bortonian (Middle Eocene); this compares favourably

with species-level diversity in the other volute genera typically associated with Athleta in

New Zealand, i.e., Mauira and Spinomelon. Five nominal Bortonian Mauira species have

been described, but one of these,M. curvispina (Marwick, 1926), has been synonymised with

M. biconica (Suter, 1917), and the status of the others is questionable (Beu & Maxwell 1990).

Three nominal species ofSpinomelon have been described from the Bortonian, and one of

these is probably superfluous.

All New Zealand records ofAthleta are in shallow-water assemblages from South

Canterbury, North Otago, and East Otago. Most species seem to have a short stratigraphic

range and are potentially useful for zonation, particularly in the Bortonian. The earliest

reasonably well-dated record isAthleta sp. indet. from the Plicatula bed, Kauru Formation

in the Pentland Hills section, upper Waihao valley (probably Mangaorapan, but possibly

Waipawan, Early Eocene). The available specimens are all juveniles, but may be conspecific

with incomplete shells from a carditid-rich shellbed (probably Mangaorapan) about 18 m

higher in the section. The latter are tentatively assigned to Athleta n. sp. A, but Athleta

specimens from a similar shellbed in Meyers Creek about 700 m distant are referred toA.

taikoensis n. sp., which also occurs in the Kauru Formation at Otaio Gorge (Waipawan or

Mangaorapan).A. lata from Castle Hill Shaft, Kaitangata Coalfield is of uncertain age but

may also be Waipawan or Mangaorapan (see below).

The Athleta succession in the Pareora Gorge Section

The lower Pareora Gorge section in South Canterbury is particularly important because this

is the only place in New Zealand where there is a clear succession ofAthleta species.

Fossiliferous sandstone and siltstone are exposed discontinuously in the banks and bed of the

river for about 700 m between Mt Misery and Mt Horrible. Exactly what is exposed at any

given time depends largely on recent flood history, and it is probably relevant in this regard

that neither Gudex (1918) nor Gair (1959) recorded any fossils from this section. Gudex

(1918) called the beds concerned crab-beds and marls and Gair (1959) gave them the

formal name Little Pareora Silt. Field & Browne (1986) tentatively referred the Little Pareora

Silt at its type locality (Little Pareora River near Maungati) to Waihao Greensand and the

upper part of the unit to Ashley Mudstone (more appropriately Burnside Mudstone).


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The oldest species recorded from the section are Athleta n. sp. A and A. taikoensis,

which occur in a slightly to moderately glauconitic, micaceous siltstone overlying

concretionary sandstone and shellbeds of Kauru Formation (Otaio Gorge Sandstone

Member); unfortunately, at the time of writing (October 2002) the siltstone is poorly

exposed and its precise relationship to the overlying Waihao Greensand is uncertain.

Microfossil evidence indicates a late Porangan or earliest Bortonian (Middle Eocene) agefor the upper part of the siltstone (see below), but the lower part may be substantially

older. It may represent the upper part of the Kauru Formation, possibly a more distal

facies of the Five Forks Member (Gage 1957).

The siltstone is overlain, probably disconformably, by glauconitic sandstone and minor

siltstone (Waihao Greensand). Molluscs from near the base of the unit includeDuplipecten

waihaoensis (Suter, 1917) and Glyptoactis (Fasciculicardia) acanthodes (Suter, 1917) which

indicate a Bortonian age, but Athleta has so far not been collected from this horizon. A.

necopinata, however, is present higher in the Waihao Greensand, particularly in a horizon

with commonLimopsiscampa Allan, 1926, about 75 m downstream from Evans Crossing,

where it is accompanied by very rare A. mimica.A. necopinata is recorded from several

localities of Bortonian age in South Canterbury and North Otago. A. mimica is possibly

descended fromA. taikoensis and also occurs at Waihao Downs (its type locality) and Opuha

River.

Athleta necopinata is succeeded abruptly in the Pareora Gorge section byAthleta sp. aff.

A. marwicki n. sp. TypicalA. marwicki occurs at the top of the section (beneath a prominent

cemented bed) and is the youngest known New Zealand species of the genus. It is probably

descended fromA. necopinata but, asAthleta sp. aff.A. marwicki andA. necopinata occur

together at Waihao Downs, their relationship is presumably not a simple one of anagenetic

speciation.A. marwicki is associated with a rich Bortonian molluscan assemblage including

Duplipectenparki (Marwick, 1942), Carinaccaallani (Marwick, 1924),Monalaria concinna

(Suter, 1917), and Speightia spinosa (Suter, 1917).

New Zealand species incorrectly assigned toAthleta

Suter (1914, 1915) assigned two other New Zealand volutes toAthleta (which he classed as

a subgenus ofVolutospina Newton, 1906, despite the former taxon having 53 years priority):

V. (Athleta) huttoni Suter, 1914 and V. (Athleta) huttoni subsp.pseudorarispina Suter, 1915,

both from Broken River, Canterbury, i.e., probably from Enys Formation, Porter River

(Altonian). (Marwick (1926) assigned these nominal taxa to his newly proposed genus

Mauia (preoccupied, = Mauira Marwick, 1943, referred to the Zidoninae); they are here

regarded as synonymous, as he himself suspected).Suter (1917) later grantedAthleta generic status and referred Volutagracilicostata Zittel,

1864 (Whaingaroan, Early Oligocene, Nelson) here as well. Zittels species, however, is now

assigned to the turrid genus Austrotoma Finlay, 1924 (Marwick 1931). Mauira huttoni

superficially resemblesA. rarispina in its callus development and tubercular sculpture, but is

much larger (height about 100 mm), has four prominent columellar plaits, and has a deep

anterior notch. Its assignment to Mauira, however, is by no means certain, as this genus

seems to have become extinct at the end of the Bortonian, along with Athleta and several

other molluscan genera. I therefore transfer the large Neogene volutes included inMauira by

Fleming (1966) and Beu & Maxwell (1990) (i.e., V. huttoni,Mauiachesteri Marwick, 1931,

M. washburnei Marwick, 1931, andAlcithoeoliveri Marwick, 1926) toAlcithoe.


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Climatic significance

The history and distribution ofAthleta is consistent with it having a Tethyan origin and

therefore forming a warm-water element in the New Zealand Paleogene fauna. To a large

degree the composition of the associated molluscan assemblages supports this conclusion.

The oldest records are probably Waipawan or Mangaorapan (see above). Evidence from

molluscs, other macroinvertebrates, and Foraminifera indicates that this was a particularlywarm period in New Zealand, possibly the warmest in the Cenozoic (Beu & Maxwell 1990;

Maxwell 2000; Maxwell & Darragh 2000). The moderately diverse faunule (Matau Fauna)

accompanying the holotype ofA. lata was described by Finlay & Marwick (1937). It includes

two genera,Electroma and Costacallista,that are confined to warm-temperate and warmer

waters at the present day, and the extinct ficid genus Priscoficus, which may also be an

indicator of warm conditions. Two species ofAthleta are recorded from the Kauru Formation

(apparently largely Mangaorapan, but possibly Waipawan near the base; G. Wilson pers.

comm.) in the Pentland Hills area, South Canterbury. The rich molluscan fauna includes such

taxa as Lithophaga, Cubitostrea, Cucullaearca, Quadrilatera, Spondylus, Plicatula (only

known New Zealand record), Septifer, Costacallista, Gastrochaena, Liotina, Polinices,Eunaticina, Cypraeoidea,Priscoficus,Pterynotus, Gemmula, Cochlespira, andPseudotorinia.

Most of these taxa are still extant and are characteristic of warm-temperate and subtropical

seas: those that are present in the modern New Zealand fauna are confined to the northern

part of the country.

Most New Zealand records ofAthleta are of Bortonian age. The Bortonian molluscan

fauna is less diverse at the genus-group level than the Waipawan/Mangaorapan (Maxwell

2000), but nevertheless includes Cubitostrea, Tellinella,Placamen, Costacallista,Eunaticina,

Cypraeoidea,Priscoficus,Ficus, Rimella,Eocithara, Typhis, Gemmula, and Conidae among

its known or assumed warm-water elements.

Athleta appears to have become locally extinct along with several other distinctive

molluscan genera (Cubitostrea, Costacallista, Monalaria, Priscoficus, Fascioplex, andSpeightia) at or near the end of the Bortonian Stage. The disappearance of these taxa from the

New Zealand fauna possibly coincides with a significant drop in sea-level near the Bortonian-

Kaiatan boundary that may in turn correspond to a cooling event (Beu & Maxwell 1990;

Maxwell 2000).

Athleta sp. indet. Fig. 1, 2

Juvenile shells from the lower part of the Kauru Formation in the South Branch, Waihao

River near Pentland Hills are specifically indeterminate and could belong in either species

group. The specimen figured here from the Plicatula bed (GS 11650) consists of the

protoconch and the first 1.5 teleoconch whorls. The protoconch is dome-shaped, of aboutthree whorls and smooth except for narrow axial costellae on the last half whorl. Teleoconch

sculpture consists of narrow well-spaced, slightly opisthocline axial costae that die out on the

upper part of the base, crossed by flattened spiral cords, the uppermost slightly stronger than

the others and somewhat more widely separated than those below, and slightly nodulose

where it crosses the ribs. The aperture is narrowly pyriform, the columella long and convex

with two narrow plaits on the upper part.

LOCALITIES: South Branch Waihao River near Pentland Hills, coral-rich shell lens in

former outcrop on left bank c. 75 m downstream from farm bridge; Plicatula bed, Kauru

Formation (Waipawan or Mangaorapan): J40/f6612, GS 11650, IGNS (3). South Branch

Waihao River near Pentland Hills, glauconitic sands with molluscs exposed in temporary


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outcrop at bottom of pool near previous locality; Kauru Formation, probably belowPlicatula

bed (Waipawan or Mangaorapan): MC/049 (5).

Athleta Group 1

Athleta lata (Marwick, 1926) Fig. 11, 12

Notoplejona lata Marwick, 1926: 271, pl. 66, fig. 1; Finlay & Marwick 1937, pp. 96, 97, 108,pl. 15, fig. 14.

Notoplejona necopinata lata;Marwick 1960, p. 23 (in part, NOT pl. 2, fig. 50, = Athleta

taikoensis n. sp.); Fleming 1966, p. 66, pl. 115, fig. 1404, 1408 (incorrectly given as 1406)

(NOT fig. 1405, =Athleta taikoensis n. sp.).

Athleta lata;Beu & Maxwell 1990, pp. 109, 416.

DESCRIPTION: Shell small for genus (height of holotype, the largest specimen originally about

27 mm), biconic-fusiform, spire about 0.3 total height. Protoconch and earliest part of

teleoconch unknown, but at least 5 teleoconch whorls remaining on holotype. Early whorls

apparently evenly convex except for narrow subsutural shelf, later spire whorls shouldered

near middle, with a somewhat less prominent angulation near adapical end, last whorl with a

steep, weakly concave zone between angulations, weakly convex below, with a shallow

medial excavation. Axial sculpture on early part of teleoconch consisting of narrow collabral

costae reaching across whorl, apparently becoming nodulose adapically at an early stage,

then developing nodules on shoulder angle. Costae on last whorl obsolete between rows of

nodules, reduced to low, rounded ridges below shoulder angle, extending across base, and

becoming almost obsolete towards close of last whorl. Upper (adapical) nodules apparently

originally as large as, or stronger than lower ones, but mostly broken off available material.

Last whorl of holotype with 9 pairs of nodules. Other axial sculpture of thread-like growth

lines. Spiral sculpture on early whorls consisting of about 10 subdued cords or threads, more-

or-less evenly distributed across whorl; last whorl of holotype with about 9 threads above

shoulder angle, another 23 weaker ones below, and 10 low, flattened cords on lower part ofbase and neck, the latter with steep edges on their adapical side, producing an imbricate

effect. Aperture narrow, inner lip almost straight, columella with 2 or 3 low folds; inner lip

callus very narrow, parietal callus thin, apparently not spreading far laterally and extending

up to suture. Outer lip varix not well preserved but apparently originally almost smooth.

Siphonal notch deep, fasciole well developed, partly covered with callus.

DIMENSIONSOFHOLOTYPE: Height (missing apex) 25.3, greatest diameter 19.0 mm.

TYPEDATA: Holotype (TM 4838) and six unnumbered paratypes, IGNS, H48/f8470, GS 759,

Castle Hill Shaft, Kaitangata, East Otago; Wangaloa Formation (age uncertain, but probably

Waipawan or Mangaorapan, see below). Five of the paratypes are considered to be conspecific

with the holotype, but one with strongly tuberculate whorls clearly represents a different

Fig. 1120 Athleta species. Fig. 11, 12Athleta lata (Marwick, 1926). Holotype (TM 4838), IGNS(height = 25.3 mm); GS 759, Castle Hill Shaft, Kaitangata, East Otago (probably Waipawan orMangaorapan, Early Eocene). Fig. 13, 14Athleta n. sp. A. Maxwell Collection (height = 26 mm), MC/007, Pareora River, c. 250 m upstream from Evans Crossing (Porangan or earliest Bortonian?, MiddleEocene).Athleta necopinata Suter, 1917: Fig.15, 17 Maxwell Collection (height = 42.7 mm); MC/009,Pareora River, South Canterbury c. 75 m downstream from Evans Crossing (Bortonian, Middle Eocene).Fig. 16 Maxwell Collection (height = 38 mm); MC/008, Pareora River at Evans Crossing (Bortonian).

Athleta sp. aff.A. marwicki n. sp.: Fig. 18, 20 Maxwell Collection (height = 49 mm); MC/112, PareoraRiver, c. 100 m downstream from Evans Crossing (Bortonian, Middle Eocene). Fig. 19 MaxwellCollection (height = 31 mm); MC/018, South Branch, Waihao River, South Canterbury, near WaihaoDowns (Bortonian).


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taxon, probably a species ofSpinomelon. Matrix adhering to this specimen contains large

glauconite grains absent from that associated with the holotype and the other paratypes.

Not only the age, but even the precise provenance of GS 759 is uncertain. The collection

came from Castle Hill Shaft in the Kaitangata coalfield but, as Finlay & Marwick (1937)

pointed out, it includes material from more than one horizon. All that they could be sure of

was that the collection came from stratigraphically much higher beds than the Wangaloanmolluscan localities exposed on the coast about 11 km to the east. For the purposes of their

study they decided to lump the different assemblages together as a single Matau fauna.

Hector (1892) had noted that several of the Castle Hill shaft molluscs seemed to be

conspecific with species from Kakahu, South Canterbury, and Black Point, North Otago. The

distinctive molluscan fauna from the last locality later formed the basis of the Bortonian,

originally proposed as a subdivision of the Waiarekan Stage (Park 1918) but later given full

stage status. Finlay & Marwick (1937) provisionally assigned the Matau fauna a Bortonian

age, but pointed out it is not typical, and held out the possibility it could be older. At the

time no stages were recognised between the Wangaloan (correlated with the Danian, then

thought to be latest Cretaceous) and Bortonian, but Finlay & Marwick (1937, p. 14) thought

the great difference in the molluscan faunas was evidence for a great lapse in time between

the two stages and that the Bortonian is probably about mid-Eocene. Finlays subsequent

foraminiferal work was to bear this out, and eventually led to the creation of five additional

stages (Teurian, Waipawan, Mangaorapan, Heretaungan, and Porangan) to cover this period

(Finlay & Marwick 1947), but the lack of microfaunas precluded precise dating of the

Matau fauna or the similar assemblage from the so-called Island Sandstone (Kauru

Formation) in the lower Waihao valley, South Canterbury. Nonetheless, Finlay & Marwick

(1948: 3233) thought that these assemblages, and a recently discovered molluscan faunule

from Pareora (actually from Otaio Gorge) could belong in the Dannevirke Series. In his

review of the Struthiolariidae, Marwick (1951) tentatively assigned the Otaio Gorge

faunule a Mangaorapan age, but later (Marwick 1960, p. 11) claimed this gave a falseimpression of accuracy and recommended correlation with the upper Dannevirke Series.

Fleming (1966) assigned molluscs described or recorded from Castle Hill Shaft, the lower

Waihao valley, and Otaio Gorge to the Dannevirke Series, but did not attempt to place them

in particular stages. Maxwell (in Fordyce et al. 1985) pointed out that the Otaio Gorge

faunule includes the widespread ostreid genus Cubitostrea, which according to Stenzel

(1971) is not known prior to the Lutetian (Middle Eocene); he therefore suggested that the

Otaio Gorge Sandstone (here regarded as a member of Kauru Formation) is of Heretaungan

or Porangan age. Beu & Maxwell (1990) arbitrarily assigned these faunules a Porangan age.

Dinoflagellate assemblages, however, indicate a Waipawan or Mangaorapan age for the

Kauru Formation at Otaio Gorge (E. Crouch pers. comm.); furthermore, Cubitostrea is nowrecorded from shellbeds of similar age in the upper Waihao valley near Pentland Hills, so

its presence does not rule out a pre-Lutetian age. The Kauru Formation in the lower Waihao

valley is also of Waipawan to Mangaorapan age (G. R. Wilson pers. comm.). There is,

unfortunately, no direct evidence for the age of the Castle Hill Shaft beds, and their correlation

with the South Canterbury faunules is not as robust as has been thought. One problem is their

preservation: it has to be said that it would have been better if most of the Castle Hill Shaft

molluscs had remained unnamed. However, some molluscs from Castle Hill Shaft do seem to

be closely related to species from the Kauru Formation in South Canterbury:

(1) Glycymerita aff. concava (Marshall, 1917) (Finlay & Marwick 1937, p. 98, pl. 14, fig. 1).

G. concava was described from Wangaloa (Wangaloan, Early Paleocene). Specimens fromMeyers Creek, upper Waihao valley (Mangaorapan) are considered to be conspecific, and are

certainly closer to G. concava than to the Bortonian G. subglobosa (Suter, 1917).


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(2) Costacallistahectori (Finlay & Marwick, 1937) (Finlay & Marwick 1937, p. 101, pl. 14,

fig. 11, 12, 16). This small venerid was described from GS 759 on the basis of partly

decorticated material. Specimens from Otaio Gorge (Marwick 1960, p. 15, pl. 1, fig. 11) and

Pentland Hills, upper Waihao valley (Beu & Maxwell 1990, p. 92, pl. 3k, l) are somewhat

more elongate but have similar coarse commarginal sculpture, in contrast to the much finer

sculpture present in an undescribed Bortonian species (Marwick 1960, p. 9).(3) Dosinia n. sp. C (Finlay & Marwick 1937, p. 101, pl. 14, fig. 8, 9). Marwick (1960) noted

the similarity of this species to hisDosinia (Kereia) n. sp. from Otaio Gorge. The latter seems

to be conspecific with an undescribed species from Meyers Creek, upper Waihao valley.

(4) Superstesinnominandus Finlay & Marwick, 1937 (Finlay & Marwick 1937, p. 110, pl.

15, fig. 17). This species was based on very imperfect material from GS 759. A specimen

from the Kauru Formation in the lower Waihao valley near Dons Hole is of comparable

size and has similarly coarse spiral sculpture.

This admittedly tenuous evidence does support broad correlation of Castle Hill Shaft

assemblages with the Waipawan or Mangaorapan faunules from South Canterbury, but a

somewhat younger (or older) age cannot be ruled out.

REMARKS:Athletalata is a poorly known species, and although the holotype is reasonably

well preserved, until recently its aperture was concealed by very hard matrix. The paratypes

are poorly preserved and very incomplete.

Marwick (1926) differentiatedAthleta lata (asNotoplejona lata) fromA. necopinata on

the basis of its lower spire and more squat shape. Finlay & Marwick (1937) noted that in

young shells the spire is of similar height in both species, and thought there was little to

distinguish them except for the smaller size and more squat shape ofA. lata. Marwick

(1960) considered the main difference from typicalA. necopinata to be its lower spire and

wider form, and therefore demotedA. lata to a subspecies ofA. necopinata. The hard matrix

obscuring the apertural face (venter) of the holotype has been removed by A. G. Beu (IGNS)

and apertural characters are now visible for the first time. The most obvious differences fromA. necopinata are its very restricted inner lip callus and thinner outer lip, but these may

merely mean the specimen is immature; however, it also differs from similar-sized A.

necopinata in its biconic rather than fusiform-subcylindrical shape, in its less prominent

sutural shelf, in having less well-developed tubercles, and in its less prominent spiral

sculpture.

Athleta lata is not known away from the type locality. Marwick (in Gage 1957) recorded

Notoplejona cf. lata from GS 5675, Dunrobin Road, Kakanui valley, North Otago (Kauru

Formation, age uncertain), but the material (IGNS) is specifically indeterminate and not even

definitely assignable toAthleta.

Marwick (1960) also referred material from Otaio Gorge to A. lata, even though heconsidered the identification uncertain. The Otaio Gorge shells resembleA. lata in size and

shape but have the subsutural nodules much weaker than the peripheral ones, have spiral

sculpture confined to the anterior end of the last whorl, and have a thick parietal callus that

extends further up the spire; they are here assigned toAthletataikoensis n. sp. (see below).

Athleta n. sp. A. Fig. 13, 14

Small Athleta specimens from micaceous siltstone in the lower part of the Pareora River

section are closest toA. necopinata in shell form and axial sculpture but are much smaller

(the largest was originally about 32 mm in height), and have almost obsolete spiral sculpture

on the adapical half of the last whorl and an almost smooth outer lip. The figured specimenwas originally only about 27 mm in height but the variciform outer lip and well-developed

inner lip callus indicates that it was probably already mature at this size; in this respect it also


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differs from typicalA. necopinata.A. lata is biconic in shape, has much weaker axial costae,

has more distinct spiral sculpture on the middle and posterior parts of the last whorl, and has

a much narrower sutural shelf, which gives the outer lip a more evenly convex outline. These

shells seem to represent another species ofAthleta but I withhold formal description until

better material becomes available.

LOCALITIES: Pareora River, c. 250 m upstream from Evans Crossing, micaceous siltstoneformerly exposed in stream bed and on sides of deep pools, but currently obscured; Kauru

Formation ?: MC/007 (2). Pareora River about 50 m north of previous locality, micaceous

siltstone underlying glauconitic sandstone in stream bed and just above normal stream level;

Kauru Formation (?): MC/079 (1). (?) South Branch Waihao River, right bank 500 m W of

Pentland Hills homestead, thin, partly cemented shellbed with abundant carditids in sands,

about 18 m abovePlicatula bed, now obscured by river gravels; Kauru Formation (probably

Mangaorapan): J40/f6608, GS9957, IGNS (2).

Matrix associated with the specimen from MC/079 yielded a good nannofossil assemblage

indicating correlation with NP16 Zone (late Porangan or earliest Bortonian, Middle Eocene)

(C. Jones pers. comm.) The two specimens from GS 9957, Pentland Hills are very incomplete,but clearly belong to this group; the spiral sculpture is much more weakly developed than in

A. necopinata, but is similar to that in the Pareora shells described above.

STRATIGRAPHICRANGE: Mangaorapan (?), Porangan or early Bortonian (early Eocene (?),

early Middle Eocene).

AthletanecopinataSuter, 1917 Fig. 1517

Athleta necopinata Suter, 1917: 40, pl. 5, fig. 7; Suter in Park 1918, pp. 34, 98; Darragh 1971,

p. 165; Beu & Maxwell 1990, pp. 109, 416, pl. 6q.

Plejonanecopinata; Suter 1918, p. 23; Suter 1921, pp. 53, 64, 65, 72.

Notoplejonanecopinata; Marwick 1926, p. 270, pl. 66, fig. 5 (but not 2?); Allan 1926, p. 289;Wenz 1943, p. 1330, fig. 3776; Marwick in Wellman 1953, p. 42; Marwick & Olson in Gage

1957, p. 113 (in part).

Notoplejonanecopinatanecopinata; Fleming 1966, p. 66, pl. 115, fig. 1406 (but not 1407?,

incorrectly given as 1408 in caption); Suggate et al. 1978, p. 410, fig. 7.3 no. 8.

Athletanecopinatanecopinata; Speden & Keyes 1981, p. 101; pl. 25, fig. 8.

DESCRIPTION: Shell of moderate size for genus (height up to about 50 mm), broadly fusiform,

spire moderately elevated, about 0.3 total height. Protoconch small, narrowly dome-shaped

of about 3 whorls, last whorl with axial costellae. Teleoconch of 5 to 6 whorls in adults, early

whorls convex then developing a narrow, subhorizontal shelf; last whorl elongate, gently

convex, gradually contracted without obvious excavation. Axial sculpture commencing asnarrow collabral costae reaching from suture to suture; on 2nd or 3rd whorl developing

laterally compressed triangular tubercles on shoulder angle and just above suture, costae

eventually becoming obsolete between tubercles, so later whorls have two rows of tubercles

without definite interconnecting costae; upper tubercles typically somewhat larger and sharper,

lower tubercles weakening near outer lip; costae on last whorl consisting of low ridges

extending across base to fasciole; 810 costae on last whorl. Spiral sculpture commencing on

about 2nd teleoconch whorl as weak threads or grooves, remaining subdued on spire whorls,

but becoming prominent on last whorl, consisting of narrow, flattened cords with interspaces

of similar width or much narrower, noticeably stronger anteriorly than on upper part of

whorl, absent from sutural shelf. Aperture narrowly subrectangular, constricted anteriorly to

form short, strongly notched siphonal canal; fasciole prominent, ridge-margined, anterior

portion covered with callus. Posterior end with distinct sinus of variable width and depth.


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Columella oblique, almost straight in subadult shells or those with incompletely formed

aperture, fully adult shells with low central pad, bearing 35 low, rounded folds, and in some

shells bordered adaperturally by a shallow longitudinal furrow. Inner lip prominently callused,

parietal callus extending up to suture; outer edge of callus attached to last whorl except for a

projecting small, hollow triangular spur near middle in most shells. Tubercles and some

spiral cords showing through callus. Outer lip typically with a prominent triangular projectionat posterior extremity, convex below except for small projection at anterior end, prosocline

and gently convex in lateral view; adult shells with prominent flattened varix, inner edge with

numerous fine lirae, outer edge rather crudely nodulose, some shells with fine spiral lirae as

well.

DIMENSIONSOFHOLOTYPE: Height 29.4 (incomplete); width 0.8 mm (crushed). (The specimen

from MC/009 (Fig. 3, 5) measures 42.7 20.6 mm.)

TYPE DATA: Holotype (TM 8242), IGNS; Waihao greensands, Waihao Downs, South

Canterbury. The preservation of the holotype resembles that of molluscs from weathered

Waihao Greensand exposed along the South Branch, Waihao River, near the abandoned

railway cutting; these are typically crushed and somewhat leached, and much less wellpreserved than those from fresher outcrops.

OTHERMATERIALEXAMINED: South Branch, Waihao River, prominent bluff on left side of

major bend, c. 800 m NW of Waihao Downs homestead, glauconitic sandstone with

abundant Limopsis campa underlying prominent bed of concretions; Waihao Greensand

(Bortonian): J40/f8858, GS 11148, IGNS (4); MC/018 (3). Kakahu, i.e., Bush Creek, a

small tributary of Kakahu River, South Canterbury; Waihao Greensand (Bortonian): J38/

f7003, GS 164, IGNS (6); J38/f7500, GS 3233, IGNS, collected by H. W. Wellman (1); M-

14615, CM, collected by P. B. Maling (12). Pareora River, South Canterbury, river bed c. 10

30 m upstream and 210 m downstream from Evans Crossing ford; Waihao Greensand

(Bortonian): MC/008 (8). Pareora River, left bank c. 75 m downstream from Evans Crossing;Waihao Greensand (Bortonian): J39/f7686, GS 11150, IGNS (8); GS 5467, IGNS (3); MC/

009 (5); J39/f7, OU 11685, OUGD (3). Black Point, Bortons, Waitaki valley, North Otago;

Tapui Sandstone (Bortonian): J41/f6520, GS 176, IGNS (1 definite record, and 2 doubtful

shells); Suter Collection, IGNS, collected by J. Park (1 young shell); J41/f6520, AU 1629,

AUGD (3). McQuades Farm, Ngapara, North Otago; Tapui Sandstone (Bortonian): OU

7385, OUGD (1). Kakanui River, left side, bluff near mouth of gully, almost opposite mouth

of Kauru River; Tapui Sandstone (Bortonian): GS 3771, IGNS (1).

Marwick & Olson (in Gage 1957, p. 113) recorded Athleta (asNotoplejona) necopinata

from four additional Tapui Sandstone localities in North Otago, but the material is either

indeterminate or could not be located in the IGNS collections.

REMARKS: The holotype ofAthletanecopinata has eight or nine costae with two rows of

laterally compressed tubercles on the last whorl, and has spiral sculpture more weakly

developed on the middle of the last whorl than above or below. The specimen is badly

crushed and lacks most of the spire and the outer lip, but it closely resembles better preserved

specimens from the Waihao Downs area and from elsewhere in South Canterbury and North

Otago.

Athleta necopinata is the most elaborately sculptured New Zealand volute, and is

distinguished from the other species considered here in having two rows of prominent

laterally compressed tubercles on adult whorls; in having spiral sculpture extending over

most of the last whorl (though weaker posteriorly than below); in its sharply angled outer lip

formed by a prominent sutural shelf; and in typically having a lateral spur on the outer edge

of the columellar callus. (One shell from Pareora River (OU 11685) has two such spurs.)


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Adult specimens from MC/008 are smaller (height of largest shell c. 39 mm) than those from

higher in the section and although they have low swelling in lieu of a definite spur (Fig. 16),

I include them inA. necopinata because of their sculptural characters. The spur is not present

in any of the Canterbury Museum specimens from Kakahu but in other respects (including

size) these shells are typicalA. necopinata.

Athletamarwickin. sp. Fig. 2124

(?)Notoplejonanecopinata (Suter); Marwick 1926, pl. 66, fig. 2; Fleming 1966, pl. 115, fig.

1407 (incorrectly given as 1408 in caption). NotAthletanecopinata Suter, 1917.

DESCRIPTION: Shell of moderate size for genus (height of largest specimen 52 mm), broadly

fusiform, spire elevated, c. 0.3 total height. Protoconch apparently as in other New Zealand

species, but lacking early whorls in most complete example. Teleoconch of up to at least 6

whorls, early whorls convex, a shoulder developing on about 2nd or 3rd whorl, becoming a

narrow but prominent shelf on later whorls, with a shallowly concave, narrow zone developing

below shoulder angle. Last whorl broadly excavated anteriorly, gently convex above except

for sulcus. Axial sculpture commencing as narrow, rounded orthocline to slightly opisthocline

costae reaching from suture to suture, but becoming obsolete on sutural shelf as shoulder

develops, costae developing low rounded nodules on shoulder angle on later whorls; costae

weakening on concave zone, no definite nodules below. Last whorl with 1213 costae

reaching almost to fasciole and weakening only slightly if at all near outer lip; interspaces

much broader than costae. Spiral sculpture commencing on 2nd whorl as fine threads or

striae, last whorl with low cords of variable spacing and width but typically flat-topped, of

ratchet profile (i.e., steeply margined adapically), covering entire whorl except sutural

shelf. Aperture narrowly subrectangular, constricted anteriorly and posteriorly; posterior

notch distinct, of variable width and depth; anterior notch deep, fasciole prominent, ridge-

margined, anterior portion covered with callus. Columella oblique, specimens with fully

formed aperture bearing a central pad with 37 low, rounded, uneven folds, pad borderedadaperturally by prominent longitudinal furrow; inner lip callus moderately thick, axial ribs

and some spiral sculpture showing through, columellar portion projecting laterally, outer

edge reflexed and thickened but lacking definite triangular spur. Outer lip prosocline with

broad, flattened varix, strongly and evenly convex in apertural view except for small projection

at anterior end, and in some shells a triangular spike at posterior end; face finely lirate.

DIMENSIONSOFHOLOTYPE: Height 42.0, width 17.8 mm.

TYPEMATERIAL: Holotype (TM 8243), IGNS; Pareora River, South Canterbury, glauconitic

sandstone with scattered macrofossils, right bank and bed c. 300400 m downstream from

Evans Crossing; upper part of Waihao Greensand (Bortonian): MC/010. Ten paratypes,

Maxwell Collection, same locality.

OTHERMATERIALEXAMINED: (?) Pareora River, c. 100 m downstream from Evans Crossing,

medium grey, moderately glauconitic, micaceous siltstone overlying upper of two prominent

cemented beds; MC/112 (5). (?) South Branch, Waihao River, prominent bluff on left side of

Fig. 2129 Athleta species. Fig. 2124Athleta marwicki n. sp. Fig. 21, 22 Holotype (TM 8243),IGNS (height = 41.5 mm); MC/010, Pareora River, c. 400500 m downstream from Evans Crossing(Bortonian). Fig. 23, 24 Paratype, Maxwell Collection (height = 40 mm), same locality. Fig. 25, 26

Athleta mimica n. sp. Holotype (TM 8245), IGNS (height = 45 mm); GS 11148, South Branch, WaihaoRiver near Waihao Downs (Bortonian). Fig. 27, 29Athleta taikoensis n. sp. Holotype (TM 8244),

IGNS (height = 33.8 mm); MC/079, Pareora River, c. 250 m upstream from Evans Crossing (Poranganor earliest Bortonian). Fig. 28Athleta rarispina (Lamarck, 1811), type species ofAthleta Conrad, 1853,WM 6721, IGNS (height = 34.5 mm); Saucats, Bordeaux, France (Miocene).


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major bend, c. 800 m NW of Waihao Downs homestead, glauconitic sandstone with

abundant Limopsis campa underlying prominent bed of concretions; Waihao Greensand

(Bortonian): J40/f8858, GS 11148, IGNS (2); MC/018 (1).

REMARKS: The above description is based on topotypes. They differ fromA. necopinata in

having a relatively higher spire; in having a more evenly costate last whorl; in having smaller

tubercles on the shoulder angle; in lacking a lower (abapical) row of tubercles; in havingmore prominent spiral sculpture; in having the outer edge of the inner lip callus detached

from the last whorl; in having a more prominent longitudinal furrow bordering the columellar

pad; in lacking the abaxial spur on the inner lip callus; and in having a less strongly

crenulated outer lip.

Shells from MC/112, near the middle of the Waihao Greensand in the Pareora Gorge

section (Fig. 18, 20), are similar in shape and most sculptural features to A. marwicki, but

have a lower row of nodules which are almost as well developed as those on the shoulder

angle, and a less strongly spreading parietal callus which in some shells retains the lateral

spur characteristic ofA. necopinata. The Waihao Downs specimens (Fig. 19) are subadult but

closely resemble similar-sized shells from MC/112. These specimens are intermediate betweenA. necopinata (present about 2 m lower in the Pareora Gorge section) and typicalA. marwicki,

but are closer to the latter. They are therefore assigned to Athleta sp. aff.A. marwicki for the

time being, although future work may justify segregating them as a distinct species. (The

Waihao Downs specimen figured by Marwick (1926, pl. 66, fig. 2) as Notoplejonanecopinata

(Suter) is more likeA. marwicki thanA. necopinata; it may be from the same locality as the

specimens here calledAthleta sp. aff.A. marwicki, but could come from higher in the section;

its present whereabouts is unknown.)

Athleta sp. aff.A. marwicki has not been found with typicalA. necopinata in the Pareora

Gorge section, but the two taxa do occur together at Waihao Downs, where they seem to be

almost equally uncommon. AlthoughA. marwicki is probably descended fromA. necopinata

or a closely related species, the relationship is not one of simple anagenetic speciation. A.marwicki presumably arose by cladogenesis fromA. necopinata some time before the latter

became extinct.

ETYMOLOGY: Named for Dr John Marwick (18911978), whose revision of New Zealand

Volutidae (1926) has remained a reliable basis for all subsequent work on local members of

this taxonomically difficult group.

Athleta Group 2

Athletataikoensisn. sp. Fig. 27, 29

Notoplejona necopinata lata;Marwick 1960, p. 23 (in part), pl. 2, fig. 50; Fleming 1966, pl.

115, fig. 1405 (NOT fig. 1404, 1408). (NOTAthletalata (Marwick, 1926).)

DESCRIPTION: Shell small for genus (original height of largest specimen about 40 mm),

biconic, spire 0.230.30 total height. Protoconch not seen, teleoconch up to about 5 whorls,

suture impressed, early whorls gently convex, angulation developing on 4th whorl, in some

shells situated near middle, on others near suture; last whorl with prominent peripheral keel,

and weaker angulation just below suture. Axial sculpture on early whorls consisting of

narrow orthocline to slightly opisthocline costae reaching across whorl, on about 3rd whorl

developing low nodules just below suture and on lower angulation, becoming obsolete

between rows of nodules, and extending only a short distance below peripheral row on last

whorl. Nodules on last whorl tubercular, those on periphery laterally compressed and much

stronger than subsutural nodules; 9 or 10 on last whorl, about 14 on penultimate whorl of onespecimen, but typically obscured by spire callus. Spiral sculpture apparently present on early


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whorls as weak lirae, becoming obsolete during growth, last whorl with 9 or 10 grooves on

neck, posterior ones very shallow, becoming more deeply incised below to form assymetrical

ridges with posterior edge much steeper, adapical half or so of last whorl devoid of spiral

sculpture. Aperture subrectangular with narrow, well-defined posterior notch and deep

anterior notch; fasciole callused. Columella oblique, padded centrally with 68 weak folds,

anterior-most typically strongest. Inner lip with prominent smooth, polished callus thatcovers most of ventral half of shell and extends up spire, apparently to top in some shells,

callus not thick enough to completely obscure peripheral nodules or spiral cords; some shells

with 1 or 2 short, narrow lirae near posterior end. Outer lip variciform, prosocline, gently

convex in apertural view, almost straight in profile, leading face flattened, inner edge smooth

to weakly and finely crenulate.

DIMENSIONSOFHOLOTYPE: Height (incomplete) 33.8 (estimated 36), width 17.6 mm.

TYPEDATA: Holotype (TM 8244), IGNS, MC/079, Pareora River, low outcrops of micaceous

siltstone in current main channel, c. 250 m upstream from Evans Crossing; Kauru Formation

? (late Porangan or earliest Bortonian; see discussion underAthleta n. sp. A, above). Two

paratypes from the same locality in Maxwell Collection.OTHER MATERIAL EXAMINED: Pareora River, c. 250 m upstream from Evans Crossing,

micaceous siltstone formerly exposed in stream bed and on sides of deep pools, but currently

obscured; Kauru Formation (?) (late Porangan or earliest Bortonian ?): MC/007 (1). Otaio

Gorge, South Canterbury, shellbeds about 5 m above coal measures; Otaio Gorge Sandstone

Member, Kauru Formation (Waipawan or Mangaorapan, E. Crouch pers. comm.): M-9883,

CM (Marwick 1960, p. 23, pl. 2, fig. 50); J39/f8539, GS 5618, IGNS, re-collection by P. A.

Maxwell (2); OU 7802, collected by R. M. Carter (1); MC/030 (2). Meyers Creek, South

Branch Waihao River, near Pentland Hills, thin shellbeds in sands, c. 100150 m upstream

from road bridge; Kauru Formation (Mangaorapan or Heretaungan, probably former): MC/

045 (2). (?) South Branch, Waihao River, left bank c. 1.5 km downstream from QuambysBridge, fallen block of weathered, highly bioturbated greensand; formation uncertain, probably

Kauru Formation: MC (1). (?) Bushy Creek, Maerewhenua River, North Otago; Kauru

Formation ?: OU 11321 (2).

STRATIGRAPHICRANGE: Waipawan?, Mangaorapan to Porangan or earliest Bortonian (Early

Eocene to early Middle Eocene).

REMARKS: Athletataikoensis is characterised by its relatively small size, prominent peripheral

nodules and restricted spiral sculpture, and in having callus spreading well up the spire.

Marwick (1960) rather diffidently assigned Otaio Gorge specimens toA. lata (asNotoplejona

necopinata lata); they differ from that species in sculpture and callus development, but

except for their smaller size (height of largest specimens about 26 mm) closely resemblespecimens ofA. taikoensis from Pareora Gorge and Meyers Creek.

The Bushy Creek specimens are moulds with the apertural face obscured, but they closely

resemble Pareora shells in size, shape, and sculpture and are probably conspecific. The age of

the site is unknown, and although it has been assumed to be in Tapui Sandstone and therefore

of Bortonian age (Gage 1957) it could be in Kauru Formation and substantially older

(Mangaorapan or Heretaungan).

ETYMOLOGY: From Taiko Stream, which joins the Pareora River near the type locality.

Athletamimican. sp. Fig. 25, 26

DESCRIPTION: Shell rather large for genus (original height of largest specimen about 47 mm),broadly biconic, spire about 0.2 total height. Protoconch poorly preserved in only example,


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apparently narrowly dome-shaped as in other New Zealand species; teleoconch of about 5 or

6 whorls in holotype; first whorl or so apparently gently and evenly convex, a narrow sutural

shelf developing on latter part of 2nd whorl, becoming more prominent during growth, last

whorl with prominent angulation on outer edge of shelf and a stronger one on periphery, area

between steeply sloping, slightly concave, base gradually contracted, almost straight. Axial

sculpture on early whorls consisting of narrow orthocline costae with wide interspaces, on3rd whorl developing tubercles on shoulder angle and periphery and eventually becoming

obsolete in between; last whorl of holotype with 11 or 12 prominent sharp tubercles on

periphery, and much weaker, more rounded nodules on shoulder angle, their number uncertain

due to weakening near the outer lip and confusion with interstitial growth ridges. Spiral

sculpture apparently commencing at or near beginning of teleoconch, consisting of 3 or 4

narrow, well-spaced cords, with others appearing during growth; last whorl of holotype with

2 weak threads on sutural shelf, 3 more prominent rounded cords between rows of tubercles,

and 7 low, flattened cords on middle and lower part of base, the area between them and

peripheral keel with only feeble sculpture. Aperture apparently subrectangular, anterior

notch deep; columella oblique, gently concave, bearing one low rounded plait. Inner lip

callus heavy, particularly posteriorly, forming a prominent parietal pad that almost completely

obscures tubercles and spreads up to shoulder angle on penultimate whorl; callus weakly

pustulose on the topotype, but slightly worn on holotype. Outer lip missing in all specimens,

but probably with a well developed varix.

DIMENSIONSOFHOLOTYPE: Height (incomplete) 45.0 (estimated c. 47), width (incomplete)

27.1 (estimated 28) mm.

TYPEDATA: Holotype (TM 8245), IGNS, South Branch Waihao River, South Canterbury,

foot of prominent bluff on left bank c. 800 m NW of Waihao Downs homestead, probably

from glauconitic sandstone with abundantLimopsiscampa Allan, 1926 underlying prominent

bed of concretions; Waihao Greensand (Bortonian): J40/f8858, GS 11148, IGNS. Paratype,

same locality, but in situ, MC/018.

OTHER MATERIAL EXAMINED: Hard band in Bortonian, Opuha R., probably left bank

Opuha River, c. 500 m downstream from Skiptons Bridge, South Canterbury: M-14830, CM,

collected by R. S. Allan (1). Pareora River, left bank c. 75 m downstream from Evans

Crossing; Waihao Greensand: MC/008 (1).

REMARKS: Only four specimens ofAthletamimica are known. The holotype was found at the

foot of a scree slope but its preservation is identical to that of the much smaller and very

incomplete paratype which was collected in situ withA. necopinata andAthleta sp. aff.A.

marwicki in the bluff above. The Opuha River specimen lacks the top of the spire, the

anterior end, and most of the last whorl, but has a parietal callus pad like that on the Waihaoshells. The other very imperfect specimen (from Pareora River) is also associated with

typicalA. necopinata.

Athletamimica is closest toA. taikoensis n. sp., and may be its direct descendant. It differs

fromA. taikoensis in (1) its larger size; (2) having larger peripheral tubercles; (3) its thicker

parietal callus which, however, does not extend up the spire; and (4) its much reduced

columellar plication.

Athletamimica is remarkably similar to the much younger type species ofAthleta, A.

rarispina (Fig. 28), in callus development and having very prominent peripheral tubercles,

but differs in its much weaker columellar plaits and deeper anterior notch. The similarity is

regarded as fortuitous, resulting from convergence rather than close relationship.

ETYMOLOGY: Mimica, Latin, a mimic, in allusion to its superficial similarity to Athleta

rarispina.


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Subfamily Volutinae Rafinesque, 1815

Pilsbry & Olsson (1954) proposed the new subfamily Lyriinae forLyria and allied taxa,

differentiating it from Volutinae on the basis of radular characters, but Darragh (1989)

pointed out that the alleged differences are not constant, nor are there reliable shell characters

that can be used to distinguish members of the two groups at the suprageneric level. (Darragh

also synonymised Volutilithinae and Calliotectinae, both of Pilsbry & Olsson, 1954, withVolutinae; the former taxon is probably not worth recognising, but Bouchet & Poppe (1995)

accept Calliotectinae as a separate subfamily.)

GenusLyria Gray, 1847

Lyria Gray, 1847: 141. Type species (original designation): Volutanucleus Lamarck, 1811;

Recent, eastern Australia, Norfolk Island, Kermadec Islands.

See Darragh 1989, pp. 207208) for synonyms ofLyria.

DESCRIPTION: Shell small for family, rather robust, broadly to narrowly ovate, spire moderately

elevated. Protoconch narrowly conical, of 2.5 to 3 whorls, or mamillate of about 1.5 whorls.

Teleoconch spire whorls convex, last whorl shallowly excavated with short, broad neck;

suture impressed to channelled. Axial sculpture of prominent gently to prominently curved

costae typically reaching from suture to suture on spire, and across last whorl to fasciole,

nodulose posteriorly in some species. Spiral sculpture usually restricted to anterior portion of

last whorl, but covering surface in some species. Aperture pyriform to narrowly ovate,

columella oblique or almost vertical, bearing 3 narrow plaits and weaker lirae above, parietal

lirae present in some species; siphonal notch shallow, fasciole rounded. Inner lip narrowly

and thinly callused; outer lip with varix, typically smooth within, rarely denticulate.

REMARKS: Two New Zealand Lyria species, Lyria sp. A. (Otaian, Parengarenga Harbour)

andLyria sp. cf.L. zelandica Finlay, 1924 (Lillburnian, Clifden) have distinctive protoconch

microsculpture. In both species the last two whorls are densely punctate, but the earlier

whorls have quite different microsculpture (Fig. 310). Punctate microsculpture seems to be

very rare in neogastropods, but has been reported on the second protoconch whorl ofVoluta

virescens Solander, 1786 (Recent, Caribbean) (Bandel 1975, p. 83, pl. 19, fig. 2).

New Zealand occurrences

Lyria is much rarer thanAthleta in New Zealand, and for many years the only record of the

genus was the Altonian (Early Miocene) speciesL. zelandica Finlay, 1924, which for a long

time was known only by the holotype. (Voluta (Lyria) corrugata Hutton, 1873 is a zidonine

and although Marwick (1926) referred it to Alcithoe, the type specimen is too poorly

preserved to be sure of its precise affinities, and it is currently regarded as a nomendubium.)

At least four, possibly five species are now known to be present, butL. zelandica is the onlyone represented by adequate material.

The oldest New Zealand record ofLyria is a juvenile shell from the Otaian (Early

Miocene) of Parengarenga Harbour, Northland; the same species also occurs in an Altonian

shellbed in the same area, where it is associated with another species. A fragment of a spire

whorl from Pakaurangi Point, Kaipara Harbour (Otaian) may also represent aLyria. None of

this material is assignable to a species.

Lyriazelandica is recorded only from the Long Beach Shellbed at the top of the Altonian

stratotype at Clifden, Southland. ALyria from the Park Bluff Sandstone (Lillburnian, Middle

Miocene) in the same section is considered to be conspecific with poorly preserved material

from Fox River, Westland (Waiauan, Middle Miocene) and to represent a different species.The youngest local record of the genus is Lyria n. sp. (?) aff. L. nucleus (Lamarck, 1811)

from Kaawa Creek, south-west Auckland (Opoitian, Early Pliocene).


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Climatic significance

In the modern fauna Lyria is largely restricted to tropical and subtropical waters in the

western Atlantic and Indo-West Pacific regions, although one species, L. mitraeformis

(Lamarck, 1811) extends as far south as northern Tasmania (Darragh 1989). The few New

Zealand occurrences of the genus are from periods in which temperatures were significantly

higher than at the present day. In particular, the presence ofLyria in the Otaian and Altonianof Northland is unsurprising, as there is ample evidence from molluscs and other fossil

groups that subtropical conditions prevailed in northernmost New Zealand during the Early

Miocene. Among the warm-water molluscs present in Northland at this time were Cryptoplax,

Arca,Pteria, Spondylus, Septifer, Chama,Hyphantosoma, Gastrochaena,Pyrazus,Antisabia,

Cheilea, Cypraeoidea, Eudolium, Chicoreus (Triplex), Rugotyphis, Coralliophila, Morum

(Oniscidia), Gemmula, Cochlespira, Conidae, and Julia (Beu & Maxwell 1990, p. 169).

What is surprising, though, is that other volutes are very rare in the Early Miocene of

Northland and Auckland; the only record known to me is Waihaoia n.sp. [probably an

Alcithoe (s.l.)] from Squadron Bay, Waiheke Island (Powell 1938). This may merely reflect

the absence of suitable lithofacies in this region, but it may mean that the predominant NewZealand volute subfamily, the Zidoninae, was at that time largely confined to cooler,

southern waters.

Lyria has not been found in any of the rich and well-studied DuntroonianAltonian (Late

OligoceneEarly Miocene) assemblages of South Canterbury and North Otago, although

Zidoninae are very well represented. (About 12 species of Zidoninae are recorded from the

North Otago Altonian alone.) The absence ofLyria and most of the other warm-water taxa

listed above is evidence that this part of the South Island occupied a distinctly cooler-water

regime than Northland during the Early Miocene, much as it does today (Beu & Maxwell

1990). Altonian molluscan assemblages from North Canterbury, however, have a warmer-

water aspect than those from further south (e.g., presence ofPlacamen and Oniscidia), so the

eventual discovery ofLyria in these faunules would not be entirely unexpected.The Long Beach Shellbed molluscan faunule includes several taxa of known or assumed

warm-water affinity: Chama, Acrosterigma, Polinices , Notocypraea , Echinophoria,

Pterynotus, Typhis, Rugotyphis, Morum (Oniscidia), Clifdenia, Gemmula, and Conidae

(Fleming et al. 1969; pers. obs.) The mid-Cenozoic warm-water province evidently extended

along what is now the west coast of the South Island to Southland (Beu & Maxwell 1990),

but the presence in the Long Beach Shellbed of common zidonines (particularly Alcithoe

phymatias Finlay, 1926) is possible evidence that conditions were somewhat cooler than

those in Northland. The Cucullaea Point Shellbed molluscan faunule is not well documented

(Fleming et al. 1969, p. 92), but Lillburnian assemblages from other horizons at Clifden

include Maoricardium, Solecurtus, Cheilea, Polinices, Echinophoria, Morum (Oniscidia),and Rugotyphis (Fleming et al. 1969; pers. obs.) and indicate that warm conditions still

prevailed in this part of New Zealand.

The molluscan faunule associated with Lyria n. sp. A. at Fox River, Westland, does not

include any other obvious warm-water taxa, but Waiauan assemblages from other parts of

New Zealand provide evidence that sea temperatures were significantly higher than at the

present day. In particular, the presence ofSpondylus in the Waikuku Limestone near North

Cape (Grant-Mackie in Leitch et al. 1969) suggests that subtropical conditions existed in

Northland at this time. Other records of warm-water molluscs from Waiauan assemblages

includeNotocypraea (Ngakonui Stream, Wairarapa), Conidae (Mohikinui River, south-west

Nelson), Septifer (Cape Foulwind, Westland), Typhis (Glenafric and Burnt Hill, NorthCanterbury), andMaoricardium, Solecurtus,Polinices, andPterynotus (Clifden, Southland)

(Beu & Maxwell 1990; pers. obs.).


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Laws (1936) concluded that the Kaawa Creek faunule lived in significantly warmer

conditions than those prevailing in south-west Auckland at the present day. Warm-water taxa

make up only a small part of this very diverse assemblage (>280 spp.), but include Miltha,

Maoricardium, Cheilea,Antisabia, Gemmula, and Conidae. Only one specimen ofLyria is

known from Kaawa Creek; it is very similar to the type species,L. nucleus (Lamarck, 1811),

which is part of the modern subtropical fauna in the south-west Pacific.

Lyria sp. indet. Fig. 36

Juvenile shells from the Otaian and Altonian of Parengarenga Harbour, Northland are

referred toLyria. The specimen from Tahuna Channel (Otaian), consisting of the protoconch

and first 1.2 teleoconch whorls, is figured here. The protoconch is dome-shaped of about 3

whorls, the last 0.2 whorl with distant narrow costellae. The nucleus bears small granules,

some of which are fused to form short spiral rows, followed by an apparently smooth zone;

the last 2.5 whorls, however, bear closely but irregularly spaced puncta that become less

dense on the last whorl. Axial teleoconch sculpture consists of narrow, slightly flexuous axial

costae that extend across the base, but not onto the neck; spiral sculpture consists of feeble

spiral striae anteriorly and more distinct grooves and cords on the lower part of base and

neck. Puncta on the teleoconch are finer but deeper than those on the protoconch. The

columella is short, twisted to the left to form a short siphonal canal, and bears 2 narrow plaits.

The protoconch is similar to that ofAthleta sp. indet. (Fig. 1, 2), but the axial costellae on the

teleoconch are flexuous and the siphonal canal is much shorter.

LOCALITY: Conglomeratic mudstone, shore platform on west side of mouth of Tahuna

Channel, north shore, Par

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