Table Of ContentAUSTRALIAN TERTIARY APATOPYGIDAE (ECHINOIDEA)
Francis C. Holmes
15 Kenbry Road, Heathmont, Victoria 3135, Australia
aiid Invertebrate Palaeontology, Museum Victoria, PO Box 666E, Melbourne, Victoria 3001, Australia
Holmes, F. C., I999;07:31. Australian Tertiary Apatopygidae (Echinoidea). Proceedings of the
Royal Society of Victoria 111(1): 51-70. ISSN 0035-9211.
The age, stratigraphic horizon and distribution of the three known Australian apatopygids
and their associated echinoid faunas are discussed. Apatopygus vincentinus (Tate 1891)
is redescribed and restricted to the Middle-Late Eocene (Johannian-AIdingan, Bartonian-
Priabonian). Two new laxa are documented: Apatopygus mannumensis sp. nov. from the Late
Oligoccne-Middle Miocene (Janjukian-carly Baimsdalian, Chattian-Serravallian) and Porterpygus
devlinensis sp. nov. from the Early Miocene (Longfordian, Aquitanian-Burdigalian). The latter
is the first fossil record of the genus.
The relationship between extant and fossil species of the family in Australia and New
Zealand is reviewed, taking into account the Late Paleocene-Early Eocene occurrence of
Apatopygus in the Chatham Islands, New Zealand,
Key words: Echinoidea, Apatopygidae, Tertiary, Australia, new laxa.
ALTHOUGH much has been written about the collecting in South Australia and Victoria by R. J.
extant New Zealand type species of Apatopygus and F. Foster, F. C. and E. Holmes, and C. AhYee
Hawkins 1920 (Nucleolites recens Milne Edwards and J. Krause, to allow a detailed comparison with
1836) and the extant Australian A. occidentalis the Middle-Late Eocene Apatopygus vincentinus.
Clark 1938, the fossil record of this genus from Porterpygus devlinensis sp. nov., the first fossil
the Tertiary of Southern Australia has been virtually record of Porterpygus Baker 1983, is also based
ignored. on specimens collected by R. J. and F. Foster.
Tate (1891) briefly described the cassiduloid
Echinobrissus vincentinus from the Late Eocene of
Aldinga, South Australia, but the species, referred
to Apatopygus by Philip (1970), was not mentioned AGE, STRATIGRAPHY AND DISTRIBUTION
in the major systematic works of Hawkins (1920),
Lambert & Thiery (1924, 1925), Brighton (1929), Middle-Late Eocene localities •
Mortensen (1948), Kier (1962, 1966) and Baker
Apatopygus vincentinus occurs in five Middle-Late
(1983). However, reference to Tate’s species, under
Eocene formations in southern Australia; the
the original binomen, appear in several 19th and
Tortachilla Limestone at Maslin Bay, the lower
20th Century faunal lists. Clark (1946) speculated
unit of the Kingseote Limestone on Kangaroo
on its possible relationship to the genus
Island and the Muloowurtie Formation on Yorke
Apatopygus, but assigned it to Nucleolites.
Peninsula, in the St Vincent Basin, South Australia
Echinobrissus vincentinus has, in the past,
(Fig. I, localities 1-3); and the Wilson Bluff and
included specimens from the Middle-Late Eocene
Toolinna Limestones at Toolinna Cove in the Eucla
and from the Late Oligocene-Middle Miocene. The
Basin, Western Australia (Fig. I, locality 4).
first record (that can be verified by recent
collecting) of the Late Oligoccne-Middle Miocene 1. The Tortachilla Limestone, considered the
form, here described as Apatopygus mannumensis origin of Tate’s syntypes from ‘Aldinga’, crops out
sp. nov., is from Spring Creek, Torquay, Victoria in the cliffs at the southern end of Maslin Bay,
(Hall & Pritchard 1896). Ludbrook (1961) first north of Blanche Point, about 40 km south of
recorded its presence in the Murray River cliffs, Adelaide. It comprises a basal bryozoal ferruginous
listing ‘cf Echinobrissus vincentinus Tate’ as sand, up to 1 m thick, grading up into 1 m of
occurring in the upper Mannum Formation at the richly fossiliferous limestone, which is overlain
Mannum Pumping Station, South Australia. irregularly by 1 m of glauconitic fossiliferous
However, it is only in the last few years that limestone (Lindsay & Alley 1995). The formation
sufficient Late Oligocene-Middle Miocene speci¬ contains a rieh echinoid fauna (Appendix 1)
mens have become available, following extensive dominated by cassiduloids.
51
52 FRANCIS C. HOLMES
2. The lowest unit of the Kingscote Limestone in the overlying coarse grained bryozoal calcarenitc
exposed in coastal cliffs at Kingscote, Kangaroo of the Toolinna Limestone.
Island, is a course grained, yellow-buff bioclastic
limestone which correlates in part with the
Tortachilla Limestone (Lindsay & Alley 1995). Age determinalicm. The Tortachilla Limestone,
Generally this unit, particularly at the southwestern the most time restricted of the five formations, has
end of the cliffs towards Brownlow Beach, con¬ in the past been considered early Late Eocene
tains a similar echinoid fauna to that of the (Aldingan, Priabonian, planktonic foraminiferal
Tortachilla Limestone, although there are often zone P15). However, McGowran ct al. (1997)
minor diagnostic and size differences between placed the Tortachilla Limestone entirely within
mainland and island specimens of the same species. the late Middle Eocene (Johannian-Aldingan?,
Bartonian, upper P14 and lower P15 foraminiferal
3. The Muloowurtie Formation, which also
zones). As parts of the lower unit of the Kingscote
correlates in part with the Tortachilla Limestone
Limestone, the lower beds of the Maloowurtie
(Lindsay & Alley 1995), crops out in the vicinity
Formation, and the upper Wilson Bluff Limestone
of Harts Mine and Muloowurtie Point, on the cast
(transitional to Toolinna Limestone) correlate in
coast of Yorke Peninsula, .south of Ardrossan.
part with the Tortachilla Limestone, these sections
Consisting primarily of yellow calcareous clays and
may also be of late Middle Eocene age.
varicolored sands it disconformably overlies the
At Maslin Bay, an irregular unconformable
Lower Cambrian Kulpara Limestone (Stuart 1970).
contact exists between the Tortachilla Limestone
4. Philip (1970) identified Apalopygus vincentiniis and the overlying Blanche Point Formation (Cooper
at Toolinna Cove, approximately 380 km southeast 1979), the lower member of which, the early Late
of Eucla. The specimens occur 9-25 m above sea Eocene Tuketja Member, is considered to lie in
level in the white chalky bryozoal calcarenitc of upper zone PI 5 (Langford ct al. 1995; McGowran
the upper part of the Wilson Bluff Limestone and et al. 1997) or lower PI6 (Lindsay & Alley 1995).
Fig. I. Distribution of Middle-Late Eocene to Late Mioeene fossil apatopygids in southern Australia.
AUSTRALIAN TERTIARY APATOPYGIDAE (ECHINOIDEA) 53
Like the Tortachilla Limestone this member, Sandstone and overlying Fossil Bluff Sandstone
although a calcareous mudstone, is also glauconitic contain a unique, although sparse, echinoid fauna
and possibly the source of some cchinoid speci¬ which includes Echinolainpas tatei Lambert 1898,
mens, including A. vinceiuinus, that have in the Monostychia etheridgei (Johnston 1877), and
past been referred to the Tortachilla Limestone. Schizaster halli McNamara & Philip 1980.
Unfortunately as the exact stratigraphic horizon
7. In southwestern Victoria, a small quarry in
from which specimens have been collected is
the Gambler Limestone, about 1.6 km north of
often unknown, the earliest and latest occurrence
Nelson, has yielded small poorly pre.served
of A. vinceiuinus in the Middle-Late Eocene of
echinoids that fit the general diagnosis of
southern Australia is still a matter of conjecture.
Apatopygus. These specimens are associated with
Although the Nanarup Limestone Member of the
the ncolampadoids Actapericuluin bicarinatuin and
Werillup Formation, exposed in a small quarry at
Notolampas Jlosculus Philip 1963, and, based on
Nanarup, near Albany, Western Australia (Bremer
the age of the Gambler Limestone outcrops in
Basin), contains an echinoid fauna similar to that
the vicinity, are Early Miocene (Longfordian-
of the Tortachilla Limestone, A. vinceiuinus has
VBatesfordian) in age (Abele, pers. comm., in
not yet been found (K. J. McNamara, pers. comm.).
Kenley 1971). A single partial specimen, also
probably Apatopygus, has been found in a quarry
Late Oli^ocene-Middle Miocene localities of similar age approximately 5 km northeast of
Mount Gambler.
Of Late Oligocene-Middle Miocene localities from
which Apatopygus is recorded (Fig. 1, Iocs 5-11), 8. Specimens of Apatopygus inannumensis sp. nov.
only the Mannum Formation in the Murray Basin
from the Mannum area, two-thirds of which were
(Fig. I, loc. 8), has yielded a significant number
collected within 6 km of the town, are from the
of specimens. The Jan Juc and Puebla Formations
bioclastic calcareous sandstone and sandy limestone
in the Port Philip Basin (Fig. 1, loc. 5), the
of the Early Miocene (Longfordian) upper Mannum
Freestone Cove Sandstone on the margin of the
Formation, expo.sed in road cuttings and cliffs along
Bass Basin (Fig. 1, loc. 6), the Gambler and Port
the Murray River between Wongulla and Mannum.
Campbell Limestones in the Otway Basin (Fig. I,
In spite of an extremely rich cchinoid fauna
Iocs 7 and 11), and the Abrakurrie Limestone of
(Appendix 2), the only other cassiduloids recorded
the Eucla Basin (Fig. 1, loc. 10), have so far
in the formation are Cassidulusl florescens (a single
yielded only rare specimens of the genus.
specimen), three species of Echinolainpas, and
5. About 25 km southwest of Torquay, the oldest Studeria elcgans (Laube 1869), although both
specimens of Apatopygus mannumensis so far the ncolampadoids Actapericuluin bicarinatuin and
recorded, have been found associated with Notolampas Jlosculus arc also present. Brown &
numerous specimens of Cassidulusi florescens Stephenson (1991), interpreted the Mannum
Gregory 1892 in yellowish sandy bryozoal cal- Formation, Morgan Limestone and Pata Limestone
carenite of the Late Oligocene-earliest Miocene? as one lithological unit, the Mannum Limestone;
(Janjukian) Point Addis Limestone Member of the the lower part encompassing the lower and upper
Jan Juk Formation, which crops out in coastal Mannum Formation of Ludbrook (1961). This
cliffs at Split Point, Aireys Inlet. Near the mouth interpretation of the Mannum Limestone which
of Spring Creek, Torquay, the Early Miocene Zeally includes the two marked bioslratigraphic zones
Limestone Member of the Puebla Formation generally referred to as the Mannum Formation
(Longfordian-?Batesfordian) is exposed in low and Morgan Limestone (Appendix 2) was adopted
cliffs at the back of the surf beach, about by Rogers ct al. (1995). However, Lukasik & James
200-300 m southwest of Point Danger, where (1998) have now divided the Mannum Limestone,
A. inannumensis occurs with Actapericuluin Murray Group of Ludbrook (1961) and Brown &
bicarinatuin Holmes 1995 in a narrow band about Stephenson (1991), into six formations, retaining
1 m above beach level. the original Mannum Formation as a separate
lithological unit.
6. Near Wynyard, on the north coast ol Tasmania,
a single poorly preserved specimen almost certainly 9. On the north side of the Murray River to
attributable to Apatopygus has been lound in the cast of Waikerie. about 115 km northeast of
the Early Miocene Freestone Cove Sandstone Mannum, Apatopygus mannumensis sp. nov. and
(Janjukian), the lower of the two calcareous marine Porterpygus devlinensis sp. nov. occur in the
formations of the Table Cape Group expo.sed at upper Mannum Formation. Associated with large
Fossil Bluff (Quilty 1972). The Freestone Cove Monostychia sp., Fericosmus coinpressus (Duncan
54 FRANCIS C. HOLMES
1877) and Studeria elegans, as well as Lovenia planktonic foraminiferal zone N16 and the basal
forbesii (Tenison Woods 1862), Ortholophus woodsi part of zone NI7 (Singleton et al. 1976).
(Laube 1869) and several brissid species, they occur
in a strongly eroded soft limestone band about
4.5 m above the level of the river Hats (R. J. MATERIALS AND METHODS
Foster, pers. comm.).
Material on which this study is based in housed
10. Philip (1970) recorded A. vincentinus in the in Museum Victoria (specimen numbers prefixed
Late Eocene of the Eucia Basin and also noted
NMV P) and the South Australian Museum (prefix
its presence in the Early Miocene Abrakurrie SAM P). Some secondary material examined for
Limestone at Thylacine Hole, just over 100 km
statistical analysis and evidence of distribution is
east of Eucia. As the latter locality contains a
currently held in the private collections of F. C.
Janjukian-Longfordian fauna, it is more than and E. Holmes, C. AhYee and J. Krause, and
likely that the specimen listed by Philip is in
A. Anderson. Measurements were made with a dial
fact A. mannumensis, although it has not been calliper to an accuracy of 0.1 mm. Parameters are
examined.
expressed as a percentage of test length (%TL)
followed by the mean, the standard deviation (SD)
11. Richly fossiliferous brown and grey to
and the number of specimens measured (N).
dark grey silty marls of the Middle Miocene
(Balcombian-Baimsdalian) Muddy Creek Marl
Member, a marginal member of the Port Campbell
Limestone (Abele et al. 1988), crop out along the
SYSTEMATIC PALAEONTOLOGY
banks of Muddy Creek east of Hamilton, Victoria.
These beds, although renowned for their rich
Order CASSIDULOIDA Claus, 1880
molluscan fauna, also contain a diverse, but poorly
recorded, echinoid fauna including Apatopygus. Family APATOPYGIDAE Kier, 1962
A single encrusted specimen has al-so been found
in the underlying yellow brown to reddish Emended diagnosis. Test small to medium, longer
brown limestone of the early Middle Miocene than wide; apical system tetrabasal or monobasal,
(Batesfordian) Bochara Limestone Member. petals weakly or moderately developed, ambulacral
plates beyond petals single pored, periproct supra¬
Age determination. Apatopygus mannumensis is marginal in groove; bourrelets incipient to slightly
recorded from the Late Oligocene-earliest Miocene developed, phyllodes single pored with up to three
(Janjukian, Chattian-Aquitanian, planktonic fora- rows of pores in each half ambulacrum, no buccal
miniferal zones P227-N4) to at least the Middle pores; demiplates (pyrinid plates) may be present
Miocene (late Balcombian-early Bairnsdalian, in ambulacra beyond petals; no naked granular zone
Serravallian, zones N10-NI2). Inconsistences in interambulacrum 5. Triphyllous pediccllariae
remain in recent publications concerning the with a medium internal keel and dentate margin.
stratigraphic range and correlation of Oligocene-
Miocene formations with southeastern Australian Genera and range. Apatopygus Hawkins, Late
regional stages and with international planktonic Paleocene to Recent; Porterpygus Baker, Early
foraminiferal zones, particularly in the Australian Miocene to Recent.
Janjukian and Longfordian stages. However,
McGowran et al. (1997) and Li et al. (1999) have Remarks. While Australian fossil apatopygids
generally fit Baker’s (1983: 164) emended familial
gone some way towards rectifying these problems.
diagnosis, a further revision is necessary as
Apatopygus mannumensis sp. nov. and the extant
A. occidentalis Clark 1938 have relatively small
Late Miocene locality
tests, and A. vincentinus (Tate 1891) and the extant
12. A single 10.1 mm long specimen of A. recens (Milne Edwards 1836) have the beginning
Apatopygus found recently in the whitish of a third series of phyllodc pores in one or both
chalky Late Miocene (Mitchellian, Tortonian) Port halves of the paired ambulacra. In addition, demi-
Campbell Limestone, in coastal cliffs northeast plates are variably present in fossil specimens and
of Nun’s Beach, Portland (Fig. 1, loc. 12), is the often restricted to the adoral surface. Lack of a
youngest known Australian Tertiary representative naked granular zone adorally on the midline of
of the genus. This .section of the Port Campbell intcrambulacrum 5 is considered to be a familial,
Limestone corresponds to the upper part of the rather than a generic trait.
AUSTRALIAN TERTIARY APATOPYGIDAE (ECHINOIDEA) 55
Genus Apatopygus Hawkins, 1920 The following separately analysed specimens from the
lower unit of the late Middle to early Late Eocene
Type species. Nucleolites rccens Milne Edwards, 1836 (Johannian-Aldingan, Bartonian-Priabonian) Kingseote
(extant) from New Zealand; original designation. Limestone, Kingseote, Kangaroo Island, were used for
comparative purposes: NMV P29501, 133074, 148363-
Emended diagnosis. Test small to medium, ovoid 148384; and SAM P35356A and B.
to subcircular at ambitus, low to moderately
inflated; apical system tetrabasal or monobasal with
Diagnosis. Small to medium sized, low to
four gonopores; petals narrow, open, usually
moderately inflated, ovate with transversely con¬
conjugate; pyrinid plating in adoral and sometimes
cave adoral surface. Apical system and peristome
adapical ambulacra beyond petals: periproct supra¬
anterior and equidistant from anterior ambitus.
marginal in groove extending to posterior margin;
Petals moderately developed, paired petals
peristome shallow to deep, bourrelets incipient to
extending about halfway to margin, unpaired petal
weakly developed, phyllodes single pored, not
three-fifths to two-thirds. Primary tubercles closely
widened, with two or possibly three series of pores
spaced adapically. Peristome deeply sunken, trans¬
in each half ambulacrum.
versely elliptical to subpentagonal, marginally wider
Remarks. This diagnosis accommodates the two than long. Periproct elliptical, steeply angled and
fossil species, A. vincentinns and A. mannumensis, partly overhung by test at anterior end of long,
which arc considerably more variable than the deep, anal groove.
extant species on which previous diagnoses have
been based. Description. Test 12.6-28.9 mm long (mean =
19.3 mm, SD = 3.6, N = 48), ovoid at the ambitus
but with sides only narrowing slightly for about
Apatopygus vincentinus (Tate, 1891) half the distance between the widest point and the
anterior margin and with the posterior margin
Figs 2A-J, 3A, D, F, 6H, 7A, D
llattened or indented medially. Maximum width
Echinohrissus vincentinus Tate 1891: 280.—Gregory 69-84% TL (mean = 78.0%, SD = 3.0. N = 40)
1892: 435. between 53-67% TL from the anterior ambitus
Cassidulus vincentinus (Tate).—Chapman 1915: 45. (mean = 60.8%, SD = 2.9, N = 33), posterior to
Nucleolites vincentinus (Tate).—Clark 1946: 354 (part.). the apex and anterior to the anal groove. Aboral
Apatopygus vincentinus (Tate).—Philip in Lowry 1970:
surface low to moderately inflated, transversely
183, (?non 186), pi. 5.—Holmes 1991: 19, figs 2D,
convex, gently curving upwards from evenly
5A-B.
rounded anterior and lateral margins to a maximum
non Apatopygus vincentinus (Tate).—Sadler, Pledge &
Morris 1983: II. height of 35-49% TL (mean = 41.8%, SD = 3.6,
N = 33) between 50-62% TL from anterior ambitus
Lectotype. SAM T266H from ‘Aldinga’, South Australia, (mean = 56.7%, SD = 3.1, N = 21). Between apex
the best preserved of Tate’s eleven syntypes, is here and posterior margin the aboral surface is more
chosen as lectotype.
steeply curved, a few specimens tending to be
Paralectotypes. SAM T266A-G and 1 from the type obliquely truncated in the vicinity of the anal
locality and SAM T266J and K from uncertain localities. groove. Adoral surface slightly concave transversely
SAM T266K is not conspecific with the rest of Tate’s between the anterior and posterior margins, mildly
specimens but is a specimen of A. mannumensis. depressed around the well of the peristome, the
degree of concavity depending on the extent
Other material. NMV P20220, 53186, 53189, 53190,
of swelling of interambulacra 1 and 4 below
79371-79374, 82021, 82022 from ‘Aldinga’; NMV
the ambitus. Primary tubercles small, sunken,
PI47943-147947 from ‘Aldinga Bay’; NMV PI33075,
148350-148362 from Maslin Bay; SAM P3328A-E from crenulate, perforate, closely spaced adapically and
•Aldinga Bay’; SAM P21955A-C, 22649A-C, 31804A around margins with progressively wider spacing
and B, 35353A-E, 35355A and B from Maslin Bay; adorally towards peristome, particularly in inter-
SAM P35354A and B purportedly from the River Murray ambulacrum 5.
cliffs but considered to be from Maslin Bay. Although Apical system, tetrabasal?, with four gonopores,
a large number of specimens are registered as being from
centre situated 36-42% TL from anterior ambitus
’Aldinga’ or ’Aldinga Bay’, all specimens, including types
(mean = 37.6%, SD = 1.4, N = 29). Gonopores
(unless otherwise noted), arc considered to be from the
small; hydropores, situated proximal to gonopore
late Middle to early Late Eocene (Johannian-Aldingan,
Bartonian-Priabonian) Tortachilla Limestone, north of 2, variable in number, maximum of 32 recorded
Blanche Point, Maslin Bay. Tate’s specimens SAM T266J in two specimens, 19.6 and 23.2 mm long. Ocular
and K were not used in statistical analysis. pores 1 and V furthest from centre of apical system.
56 FRANCIS C. HOLMES
AUSTRALIAN TERTIARY APATOPYGIDAE (ECHINOIDEA) 57
Petals moderately developed, Hush, fairly narrow, at Maslin Bay. Specimens from Kingseote,
straight, open distally; posterior pair longest; Kangaroo Island, fall within the limits of the
anterior pair shortest. Posterior paired petals species but generally have a wider and higher test
extending 44-57% of the radius (mean = 51.5%), (Fig. 5B), less concave adoral surface, and
measured from centre of apical system along marginally shorter anal groove with steeper angled
perradial suture to the ambitus; anterior paired periproct (Fig. 5D).
petals 45-61% of radius (mean = 53.2%); anterior Apatopygiis vincentiniis is distinguishable from
unpaired petal 57-70% of radius (mean = 62.6%). the extant type species A. recens by its more
Anterior paired petals diverge 130-148° (mean = restricted size range, narrower test, more anterior
139°); posterior paired petals 300-316° (mean = apical sy.stcm with fewer hydroporcs, and much
309°). Inner pore of pore pair round, outer pore narrower peristome. It also differs from the extant
round to marginally oval, pore pair spacing about A. ocddentalis by having shorter petals in
4 per millimetre, interporiferous zone 1.5-2.0 times ambulacra I and V, more widely spaced primary
width of pore pair. Maximum number of pore tubercles, a transversely elongated peristome, and
pairs 24 in ambulacra I and V, 19 in II, III and a steeper angled periproct. A. vincentinus has
IV (specimen 22.1 mm long). greater anal groove Icngtli/width ratio, and far
Phyllodcs not expanded, only weakly developed; greater distance between the posterior margin and
pores in shallow pits form biserial rows in each the posterior edge of the periproct than either
half ambulacrum in II, III and IV, tending to extant species. It is also highly probably that the
triserial in I and V; first pore in the inner series two species have different apical plate structures;
situated just inside the well above the peristome A. ocddentalis being described by Baker (1983)
(Fig. 3A). A small number of closely spaced non- as monobasal, while an adult specimen of
perforate pits also occur between the inner series A. vincentinus from the Kingseote Limestone
of pores close to the peristome. Adoral plate (Fig. 3F) and one from the Tortachilla Limestone
structure of ambulacra visible on one or two clearly show a tetrabasal system.
specimens, with demiplates only evident on one of The difference between A. vincentinus and
these (Fig. 3D). Incipient bourrelets present. A. ocddentalis are based purely on a comparison
Peristome anterior, transversely elliptical to sub¬ with Baker’s (1983) description, measurement and
pentagonal, with posterior edge slightly Hattcncd, illustration of the latter.
length 7-12% TL (mean = 8.1%, SD = 1.0, N = 23), In South Australia, Apatopygus vincentinus
width 9-13% TL (mean = 10.8%, SD = 0.9, N = usually occurs with two other Late Eocene
22), at base of moderately to deeply sunken well cassiduloids, Aiatralanthus longianus (Gregory
with granulated sides, 37-42% TL to centre from 1890) and Eurhodia australiae (Duncan 1877), that
anterior ambitus (mean = 39.4%, SD = 1.1, N = 33). share many similar cassiduloid features. However,
Periproct 6-10% TL wide (mean = 8.2), long¬ the latter forms are easily distinguished from
itudinally elliptical and angled at more than 45° Apatopygus vincentinus by their more posterior
to the horizontal at the anterior end of a deep anal periproct, well developed phyllodes and bourrelets,
groove, length 3.0-4.5 times width, extending to and wide naked or pitted zone adorally on the
the posterior margin. Forward edge of periproct midline of interambulacrum 5. A comparison with
opening is below and anterior to the vertically A. mannumensis sp. nov. is given below.
visible end of the anal groove which is situated
61-75% TL from anterior ambitus (mean = 69.5%,
SD = 3.6, N = 36). Base of the anal groove may Apatopygus mannumensis sp. nov.
rise above posterior edge of periproct opening
Figs 3B, E, 4A-E, 7B, E
before curving down to posterior margin.
Nucleolites vincentinus (Tate).—Clark 1946: 354 (part.).
Remarks. Statistical analysis is based solely on Apatopygus vincentinus (Tate).—Sadlers, Pledge & Morris
measurement of specimens from the type locality 1983: II.
Fig. 2. Apatopygus vincentinus Tale. A, C-E, adapical, adoral, posterior and lateral views (x3.3), and B, detail
of apical system (xl3) of leclotype SAM T266H, from the Middle-Late Eocene Tortachilla Limestone, Aldinga
Bay (?Maslin Bay); F, I, J, adapical, posterior and lateral views (x3). and G, detail of apical system (xl3) of
NMV P148364, and H, detail of apical system of NMV P14837() from ttie Middle-Late Eocene Kingseote
Limestone, Kingseote, Kangaroo Island.
58 FRANCIS C. HOLMES
Fig. 3. A-C, phyllode pore arrangement in ambulacra I. II and III (xl2); D, demiplate (pyranid) plate structure
in adoral ambulacrum III (x8); and E and F, apical plate structure (xI6). A. D. F, Apatopygus vincenlinus (Tate);
A, NMV PI48362 and D, SAM T266D from the Middle-Late Eocene Tortachilla Limestone, Maslin Bay, and
F, NMV PI48377 from the Middle-Late Eocene Kingscote Limestone, Kangaroo Island. B, E, A. mannumensis
sp. nov.; B, NMV PI48496 and E, NMV PI4839I, from the Early Miocene Mannum Formation, near Mannum.
C, Porlerpygus devlinensis sp. nov.; NMV PI48399, from the Early Miocene Mannum Formation, near Waikerie.
In A-C, edge of recess above peristomal opening is indicated by long broken line and non-perforate pits by
broken circles.
AUSTRALIAN TERTIARY APATOPYGIDAE (ECHINOIDEA) 59
Elym()l(>i>y. Erom Mannum, a Murray River town near and peristome anterior, the latter further from the
which the majority of specimens were collected. anterior ambitus. Petals poorly developed, paired
petals extend less than halfway to margin, un¬
Holotype. NMV PI48496 from the Early Miocene
(Longfordian, Aquitanian?-Burdigalian) Mannum For¬ paired petal just over halfway. Primary tubercles
mation, Cowirra Swamp Road, near Mannum; collected moderately spaced adapically. Peristome in shallow
by J. Krause and C. AhYee, April 1996. depression, transversely elliptical, wider than
long. Pcriproct longitudinally elliptical, moderately
Paratypes. NMV P148385 and 148386 from Coolcha
angled at anterior end of long, shallow, anal groove.
Landing. Younghusband; NMV P148387 from Caurna-
mont; NMV P148388 from Walker Flat; NMV PI48389 Description. Test 9.1-14.5 mm long (mean =
and 148390 from Underwood Hill Road, Mannum; 11.3 mm, SD= 1.4, N = 23), elliptical to ovoid at
NMV PI4839I-148395 from side of road 3.4 km NE
the ambitus with posterior generally rounded and
of Mannum. All from the Early Miocene Mannum
only rarely indented medially. Maximum width
Formation, South Australia.
74-82% TL (mean = 77.9%, SD=1.9, N = 21) at
Other material. Thirteen other specimens (currently held 51-65% TL from the anterior ambitus (mean =
in private collections) from the Early Miocene Mannum 59.0%, SD = 3.5, N=I9), about halfway between
Formation near Mannum.
the apex and the anterior end of the anal groove.
The following separately analysed specimens were
Aboral surface mildly inflated, transversely covex,
used for comparative purposes: NMV P148404 and
148405 from the Late Oligoccnc Jan Juc Formation, gently curving upwards from evenly rounded
Point Addis Limestone Member, Aircys Inlet; NMV anterior and lateral margins but flattening out in
PI 48406-148408 from the Early Miocene Puebla vicinity of apex. Maximum height 37-48% TL
Formation. Zcally Limestone Member, Point Danger, (mean = 43.2%, SD = 2.8, N = 21) at 48-56% TL
Torquay; NMV P148409-148411 from the Early Miocene from anterior ambitus (mean = 53.6%, SD=L7,
Gambier Limestone, Nelson; and SAM P27908 from an N=16). Aboral surface evenly curved between
unknown locality and horizon, Murray River cliffs.
apex and posterior margin. Adoral surface mildly
Diagnosis. Small, moderately inflated, ovate, with concave transversely between anterior and posterior
transversely concave adoral surface. Apical system margins, slightly depressed around the peristome.
Fig. 4. Apatopygiis matmumensis sp. nov. A, B, D, E, adapical, adoral, posterior and lateral views (x4) of
holotype NMV PI48496, and C, adapical view (x5.5) of paratype NMV P148393 from the Early Miocene Mannum
Formation, near Mannum.
60 FRANCIS C. HOLMES
Primary tubercles moderately small, sunken, separately analysed Late Oligocene and Early
crenulatc, perforate, fairly widely and evenly spaced Miocene specimens from near Torquay (Jan Juc
over the whole test, marginally further apart and Puebla Formations), and from Nelson (Gambler
adorally. Limestone), are comparable with the new species,
Apical system, anterior, centre situated 33-38% showing only very minor variations in periproct
TL from anterior ambitus (mean = 35.3%, SD = 1.2, size and anal groove length.
N = 15). A tetrabasal (ethmophract) apical system Although previously considered a small form of
plate arrangement, visible on only one 13.1 mm A. vincentinus, A. manniimensis differs by having
long specimen (Fig. 3E), with 4 medium sized relatively shorter petals in ambulacra II, III and
gonopores and large pierced ocular plates, posterior IV, and relatively longer petals in I and V; more
pair, I and V, in contact with each other. Specimens divergent anterior paired petals; more evenly
show 5-12 hydropores proximal to gonoporc 2. and wider spaced primary tubercles; a shallow,
Petals flush, narrow, short, straight, open distally; marginally wider and often transversely pointed
posterior pair longest; anterior pair shortest. peristome; and a much longer, shallower anal
Posterior paired petals 41-53% of radius (mean = groove with a wider and lower angled periproct,
45.6%), measured from centre of apical system not anteriorly overhung by the lest (Fig. 7E).
along the perradial suture to the ambitus; anterior Like A. vincentinus it differs from extant
paired petals 38-54% of radius (mean = 46.3%); A. occidentalis in anal groove length and distance
anterior unpaired petal 47-65% of radius (mean = of periproct from the posterior margin. In addition
55.3%). Anterior paired petals diverge 138-153° A. manniimensis has a less posteriorly located
(mean =145°); posterior paired petals 306-312° maximum test width and, unlike A. occidentalis,
(mean = 309°). Pores round; pore pair spacing does not have a semicircular peristome or very
about 4 per millimetre, interporiferous zone 1.5- closely spaced primary tubercles.
2.0 times width of pore pair. Maximum number A. manniimensis has a strong superficial resem¬
of pore pairs 17 in ambulacra I and V, 12 in II blance to the small neolampadid Actapericiiliim
and IV, and 13 in III (specimen 13.1 mm long). bicarinatiim with which it is sometimes found;
Phyllodes not expanded, barely developed; pores however, the latter species is recognisable by well
in shallow pits form biserial rows in each half developed bourrelets and a lack of petals.
ambulacrum with the first pore of the inner series
just inside the slight depression around the
peristome (Fig. 3B). A small number of closely
spaced non-perforate pits occur between the inner Genus Porterpygus Baker, 1983
series of pores close to the peristome. Adoral plate
Type species. Porlerpyj’us kieri Baker, 1983 (extant)
structure of the ambulacra is unknown. Bourrelets
from near Three Kings Islands, New Zealand; original
incipient.
designation.
Peristome anterior, transversely elliptical, some¬
times with lateral edges pointed and posterior edge Diagnosis. See Baker (1983: 164)
slightly Battened, length 7-11% TL (mean = 9.0%,
SD=1.0, N=15), width 11-16% TL (mean =
13.0%, SD=1.3, N=17), situated in shallow
Porterpygus devlinensis sp. nov.
depression 38-42% TL to centre from anterior
ambitus (mean = 39.4%, SD=L1, N=198). Figs 3C, 6A-G, 1C, F
Periproct longitudinally elliptical, with anterior
edge sometimes pointed, horizontally 12-19% TL Etymology. From Devlins Pound, an early settlers’ trap
long (mean = 16.5%), 8-13% TL wide (mean = for mustering horses on the river Hats, near where the
specimens were found.
10.8%); opening angled 30-40° to the horizontal
at the anterior end of a long shallow anal groove Holotype. NMV P148399 from the Early Miocene
with length 2.8-4.0 times width, extending to the (Longfordian) Mannum Formation expo.sed in cliffs on
posterior margin. Anterior end of anal groove 58- the right bank of the Murray River about 16 km cast
67% TL from anterior ambitus (mean = 63.5%, of Waikerie (NMV PL3430).
SD = 2.5, N = 2I).
Paratypes. NMV PI48396-148398, 148400 and 148401
from the type locality.
Remarks. Statistical analysis used in the des¬
cription is based on specimens collected from Diagnosis. Small to medium, low, ovate, with
the vicinity of the Murray River between Walker transversely concave adoral surface. Apical system
Flat and Mannum (Mannum Formation). Other and peristome anterior, the former much closer
