Fossil fruit of the Macadamieae (Proteaceae) in the Tertiary of eastern Australia: Eureka gen. nov

2010·7.2 MB·English

by  Mary E Dettmann

Fossil fruit of the Macadamieae (Proteaceae) in
the Tertiary of eastern Australia: Eureka gen. nov.
Mary E. DETTMANN
H. Trevor CLIFFORD
Queensland Museum, Geosciences, Hendra Facility, 122 Gerler Rd, Hendra, Qld 4011, Australia.
Email: [email protected]
Citation: Dettmann, M.E. &Clifford, H.T.201003 15. Fossilfruitofthe Macadamieae(Proteaceae)
in the Tertiary of eastern Australia: Eureka gen. nov.. Memoirs ofthe Queensland Museum —
Nature 55(1): 147-166. Brisbane. ISSN 0079-8835.Accepted: 13 October2009.
ABSTRACT
Eureka gen. nov. is proposed to accommodate fossil fruits recovered from several mid-
Tertiary (early Oligocene-Miocene) sites in eastern Australia. The type (E. welcomensis
sp. nov.) and other described species (E.(a/. Conchotheca) turgida (F. Muell.) comb,
nov., E. spechtiisp. nov., E. harslettiae sp. nov.) have bilaterally symmetrical, ellipsoidal
pericarps that are uniloculate, 1-seeded, and tardily dehiscent along the ventral suture
and dorsal hinge line. The pericarp wall is radially structured and has a branched
vasculature system capped by fibres embedded in a thick mesocarp; the radial fibres
extend into the exocarp, and the endocarp is thin or lacking. The seed is orthotropous,
attached apically and with a 2-layered seed coat that has an endotestal cuticle bearing
impressionsoftransfercells. Eureka is morphologicallyand anatomicallyconsistentwith
fruits ofextant members of Bleasdalea F. Muell., Hicksbeachia F. Muell., and Gevuina
Molina ofsubtribe Gevuininae (tribe Macadamieae, family Proteaceae). Accordingly, the
fossilfruitevidence impliesthattheGevuininae had aformerdistribution rangespanning
some 20° of latitude in eastern Australia and taken togetherwith fossil cuticle evidence
a trans-Tasman distribution no longer mirrored in the present vegetation. Eureka also
displays some resemblance to the tardily dehiscent fruits of extant Panopsis (subtribe
Macadamiinae, tribe Macadamieae); however, morphological/anatomical details of
extant members are imprecisely known. Australia, Bleasdalea, Eureka, fossil fruit,
Gevuina, Hicksbeachia, Macadamieae, Tertiary.
Among recently recovered woody fossils mesocarp. Similarly structured pericarps charac-
from Tertiary sediments at several localities terise fruits borne by extant genera of tribe
in Queensland are several different types of Macadamieae. The distinctive vasculature
1-seeded, tardily dehiscent, uniloculate fruits patternwith'third-orderradialvascularbundles'
with vascularised pericarps similar to those of (Johnson & Briggs 1975, p.134; Douglas 1995,
fruits borne by several extant genera included p.18) comprises prolific radial branching of
within tribe Macadamieae (Proteaceae) as the main vertical and lateral (tangentially-
recently redefined (Weston & Barker 2006; Mast aligned) bundles in a woody ground mass of
et al. 2008). The Queensland fossil fruits are predominantly radially oriented fibre sheaths
spheroidal toellipsoidal, near-symmetrical about thatsurround the bundles as detailed for fruits
the vertical axis, and their thick pericarp has a of several extant members of the tribe (Filla
distinctive radial structure reflecting a branched 1926; Strohschen 1986a,b). The Queensland
vasculature system embedded in a thick, woody fossil fruits with their near vertical symmetry,
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Dettmann & Clifford
near-smooth outer surface of pericarp, and shown to be insufficiently discriminatory of
one apically attached unwinged seed having theextant taxa in parsimony analyses (Sauquet
a 2-layered, non-woody seed coat are more et al. 2009); thus far, P. tripartus has not been
similar to fruits of several genera Gevuina tested in any comparablecladistic analysis.
(
Molina, Hicksbeachia F. Muell., and Bleasdalea
F. Muell.) ofsubtribeGevuininaethan toother MATERIAL
members of tribe Macadamieae. Previously
described fossil fruits that possess a thick Fruitsreported upon here includewoody and
pericarp with third order vasculature were charcoalified and permineralised specimens.
assigned to Conchotheca turgidaF. Muell., a taxon The charcoalified specimens were recovered
reported from mid-Tertiary deep lead sediments from subsurface sediments near Blackwater
in Victoria (Mueller 1874a, Deane 1925) and and Moranbah, central Queensland and
Tasmania (Johnston 1880). Mueller (1874a) did Bundaberg, southeastern Queensland and the
notcommentonthebotanicalaffinityofC. turgida, permineralised specimensarefrom anoutcrop at
butexaminationofhisprotocol materialconfirms Glencoe, central Queensland; all are held in the
these fossils, too, are morphologically consonant Queensland Museum (QMF). Also examined are
with fruits of subtribe Gevuininae, being similar woodyandcharcoalifiedfruitscollectedin thelate
to those of Gevuina, Bleasdalea, and Hicksbeachia. 1800'sandearly1900'sfromseveralgoldfieldsites
Evaluation of Mueller's protocol material and of in Victoria and New South Wales and housed
the Queensland fossil fruits form the basis of the in the Queensland Museum, the Australian
presentstudy. Moreover,comparisonshavebeen Museum (AMF) and the Museum of Victoria
undertaken of the fossil material with fruits of (NMVP).Thelast-mentionedcollectioncontains
extant Gevuina, Hicksbeachia, and Bleasdalea. the type and other specimens of the protocol
Extant Gevuina is monotypic and endemic mwahtiecrhiawlaosf CoroingcihnoatlhleycahotuursgeiddaiFn.tMhueelMlu.,s1e87u4m,
to southern South America; Bleasdalea has two
species, one each in New Guinea and eastern of the Geological Survey of Victoria (GSVF).
Locality details of occurrences of Eureka gen.
Australia, and Hicksbeachia, with twospecies, is
endemic toeastern Australia (Fig 1A; Weston & nov. are as follows (see also Fig. IB).
Barker 2006). Fossil cuticles that are consistent Queensland, a) Picardy Station, near Moranbah
with those of subtribe Gevuininae have been (21°5'17.6'S 147°50'34.3'E) RioTinto Exploration
reported from Eocene sediments of Western Hole RDPD98MA21, sands, silts and lignites
Australia (Carpenter & Pole 1995) and from at 123-133 m; Early Oligocene (Dettmann &
the Miocene of New Zealand (Pole 1998). Clifford 2001).
Fossil wood similar to, but not identical with, b)NearBlackwater(24°1'1.3'S148°48'50'E)South
Gevuina has been reported from the Oligocene
Blackwater Coal Pty Ltd Hole R8736, sands
ofPatagonia (Pujana 2007).
and lignites at 82m; Early-Late Oligocene
The fossil pollen taxa, Propylipollis reticulo- (Dettmann & Clifford 2001).
stcraipbarrattuussH(aHrarrirsi,s)whHiacrhrisocacnurd iMnarCtaimnp,aannidanP-. c)GlencoeStation(23°36SI48°06'E),nearCapella,
Tertiary sediments of Australia, New Zealand silcrete outcrop; 01igocen&e-?Early Miocene
and Antarctica, are morphologically similar to (Rozefelds1990;Rozefelds Christophel1996;
pollen of Gevuina, Bleasdalea, and Hicksbeachia Dettmann&Clifford 2001).
(Martin 1982; Dettmann & Jarzen 1990, 1996, d) N of Bundaberg (24° 46'49'S 152°18'17'E),
1998). P. reticuloscabratus however, has been HerbertsonWelcomeCreekDrain,subsurface
148 MemoirsoftheQueensland Museum Nature • 2010 • 55(1)
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Fossil Proteaceous fruits
sands and clays; Early Miocene (Dettmann withoutwhitening. Thinsectionsofcharcoalified
& Clifford, 2003). specimens were cut using a slide microtome
e) NearClifton (27°55'S151°55'E), Queensland and mounted in glycerinejelly on glass slides
WaterResources borehole, sandsand lignites for transmitted light microscope analysis.
Fragmentsofseveral specimenswere mounted
at 45-46 m; Tertiary (?Miocene).
on stubs and gold plated for scanning electron
frlexv South Wales. Near Orange (33°17'S 149° microscope analysis. Anatomical features of
06'E, Forest Reefs Mine, deep lead sediments; seed coats were examined in transmitted light
late Middle-early Late Miocene (Johnson 1989; after clearing in a weak solution of sodium
Dettmann & Clifford 2001) hypochlorite, followed by thorough washing
Victoria, a) Nintingabool (Crucible Co. Shaft), in distilled water.
near Haddon (37° 18'S 146°32'E), SW of Photographs were captured on either T Max
Ballarat, deep lead sediments; Oligocene- film or digitally using an Olympus Cameida
Miocene (Greenwood et al. 2000; Dettmann & C-5050 camera. Images were processed using
Clifford 2001; Holdgate et al. 2006). Photoshop 5LE.
b) Foster(37°10'S146°14'E),deepleadsediments; SYSTEMATIC DESCRIPTION
&
Oligocene-Miocene (Rozefelds Christophel
1996; Holdgate et al. 2008). FAMILY - PROTEACEAEJUSS.
Tasmania. Brandy Creek, Beaconsfield (41°12'S
148°49'E), deep lead sediments; Oligocene SUBFAMILY-GREVILLEOIDEAE ENGL.
(Forsyth 1989)
TRIBE - MACADAMIEAE C.VENKATA RAO
METHODS
SUBTRIBE GEVUININAE
- L.A.S.
Fruitsstudiedincludecarbonaceousspecimens JOHNSON & B.G. BRIGGS
retaining well preserved morphological and
anatomical characters of their woody tissues to Genus -Eureka gen.nov.
severely vitrinised specimens retaining external
and internal morphologybutwith fewanatomical Derivation of name. With reference to the
characters preserved.Someof thecarbonaceous association of 'Eureka' (Eureka Stockade, Eureka
fruits are pyritised and, as a result ofoxidation Flag, Eureka Deep Lead) with early gold mining
since collection, several have fragmented. Per- activities in and around Ballarat, Victoria.
mineralised specimens are composed of
amorphous and/or cryptocrystalline quartz Generic diagnosis. Fruit unilocular, indehiscent
that has preserved external and internal to tardily dehiscent woody follicle; ellipsoidal
morphology of the fruits, but no anatomical or spheroidal, symmetrical about the vertical
axis. Style base near-opposite stalk in the
detail of the original tissues is preserved.
vertical plane; ventral suture and dorsal hinge
Charcoalified specimens were photographed line approximately equal in length; splitting
eitherafterwhiteningwithammonium chloride along ventral suture and dorsal hinge into 2
tohighlightsurfacefeaturesorwithout whitening near equal portions. Surface smooth or near-
to illustrate internal characters including those smooth. Pericarp largely composed of meso-
of the locules, seeds, and internal anatomy. carp, the outer thicker part with a branched
Permineralised specimens were photographed vascularsystemcomposed ofverticallyaligned
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Dettmann & Clifford
FIG. 1. Polar stereographic projections, based on Lawver & Gahagan (2003). A, Present Day showing
distribution-range ofextant members ofSubtribe Gevuininae (excluding Cardivellia); B, Early Miocene (20
Mya) showing localities offossil Eureka (*), fossil cuticles (C) ofSubtribe Gevuininae, and fossil wood (W)
questionably allied toSubtribeGevuininae.
(tangential) primary bundlesfrom which branch havingverticallyaligned, unbranched vascular
radially aligned secondary bundles that are bundles in the mesocarp and laterally attached
surrounded by tangentially and radially seeds. One taxon, C. turgida, allocated to
aligned fibre bundles; fibres interspersed with Conchotheca by Mueller (1874a) ischaracterised
parenchyma. Exocarp and endocarp thin. Seed by a pericarp with a branched vascular system
solitary, unwinged, orthotropous, attached
and an apically attached, orthotropous seed;
apically, filling, or almost so, locule. Seed
this species is transferred herein to Eureka.
coat 2-layered, the outer layer incompletely
enveloping the inner; outer layer a cuticle Eureka is distinct from Conchocaryon F. Muell.
with impressions of transfer cells; inner layer a 1879, which has asymmetric fruits and laterally
cuticle with anticlinal walls ofrectilinearcells. attached winged seeds (Mueller 1879; Dettmann
Typespecies. Eurekawelcomensissp. nov. &Clifford2005). BothPlesiocapparisF. Muell.1871
Remarks and comparison. Eureka gen.nov. and Celyphina F. Muell. 1871 have indehiscent,
accommodates uniloculate fruits having a unilocular, near-smooth fruits with branched
branched vascular system surrounded by fibre vasculature in the mesocarp. They differ from
bundles in the mesocarp, and a single apically Eureka in possessing large stonecell complexes
attached, orthotropous seed. In these respects (not radially oriented fibres) that cap and
Eureka differsfrom ConchothecaF. Muell.,emend. surround the vascular bundles in the fruit wall
Dettmann&Clifford2005,whichincludesfruits (Dettmann & Clifford, in prep.).
150 MemoirsoftheQueensland Museum Nature • 2010 • 55(1)
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Fossil Proteaceousfruits
FIGS2-16. Eurekawelcomensisso. nov.; 2-4, Lateral, apical and basal viewsofholotypewithseed (arrowed),
QMF51143; scalebar =5mm; 5-6, Pericarp, lateral view showingsurfaceofloculeandexternal lateral view
showing V-shaped scar (arrowed) of style base, AMF11099; scale bar = 5 mm; 7, 8, Pericarp, surfaces
of locule, lateral view, QMF51144; scale bar =5mm; 9, Detail of style scar (arrowed) on external surface
of fruit, QMF51145; scale bar = 2.5 mm; 10, Pericarp wall, transverse section at right angles to the dorso-
ventral plane showingvasculatureassociated with style base (arrow), QMF51145; scale bar = 1 mm; 11,
12, Pericarp wall, section in planeofdorsal hinge line and ventral sutureshowing vasculaturecomprising
eroded vertical (v) bundles iscross section and radially aligned secondary bundles (r) surrounded by fibre
complexesembedded ina ground massofparenchyma, QMF51145; scale'bar= 1 mm; 13,14, Pericarp wall,
structure in transversesectionsshowingwall fibrebundlecomplexessurroundingvasculature, QMF51149;
scale bar=100 pm; 15, 16, Pericarpwall in transversesectionshowingfibrebundlessurroundingbranched
vasculatureand detail offibres,QMF51150;scalebar=100 gm and10 gmrespectively.
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Dettmann & Clifford
Species - Eureka welcomensis sp. nov. Dimensions. Pericarp (8 specimens); vertical
(Figs 2-24) axis12.5 (18.5) 23 mm, lateral axes 12.5 (16.8) 22
mm mm
(in plane of dehiscence) x 10 (15.6) 20
Holotype. QMF51143 (Figs 2-4). Prolate ellipsoidal, (at right angles to dorso-ventral plane). Seed (4
unilocular, 2-valved fruit, partially dehisced into specimens); vertical axis 12-16 mm, lateral axis
2 subequal valves along ventral suture and dorsal
hinge line; stalk scar indistinct, scar of style base 8-10 mm.
orientedtransversetodorso-ventralplaneextending4-5
mmfromapextowardsbaseonmid faceofeachvalve. Derivation ofname. Withreferenceto the type
Pericarp4-5mmthickinlateralregions,thinner(3mm) locality and in allusion to The Welcome' gold
atapex. Seed solitary, apicallyattached, orthotropous. nugget, recovered during 1858, from a Deep
Verticalaxis19mm;lateralaxes19mm,16mm. Lead at Bakery Hill near Ballarat, Victoria.
Other material. QMF51144-QMF51151 inclusive,
AMF11099. Remarks. The majority of specimens were
Type locality. Herbertson WelcomeCreekDrain, N collected in an undehisced state (Figs 2-4), but
of Bundaberg,Queensland; Early Miocene. on drying after collection, the valves ofseveral
of them separated either partially or wholly
Diagnosis. Fruit woody, prolate ellipsoidal, from the apex and along the ventral suture
near symmetrical about the vertical axis; thereby to reveal their seed coats attached to
indehiscent or tardily dehiscent, unilocular, the pericarp wall (Fig. 17).
with 1 apically attached seed. Stalk attachment
basal, inconspicuous; style base represented Distribution. Herberts on Welcome Creek
by a linear groove oriented transverse to the Drain, N of Bundaberg; near Clifton, Darling
mm
dorso-ventral planeandextending4-5 from Downs; Picardv Station near Moranbah Hole
apex on lateral surface of each valve; groove RDPD98MA21, 123-133 m, Qld; Forest Reef,
underlain by vascular strands that extend into nearOrange, NSW.
the pericarp and terminate near the seed cavity.
Pericarp with near smooth outer surface, Agerange. EarlyOligocene-early LateMiocene.
thickest (4-6 mm) in basal and mid regions of
lateral surfaces, tapering to3-4 mm atapexand Species - Eureka turgida (F. Muell.)
comb. nov. (Figs 25-30)
alongboth ventral suture and dorsal hingeline;
wall comprises thin exocarp overlying a thick 1874aConchothecaturgidaMueller,p.42;Pl.X,8,12(nonfigs
vascularised mesocarp and a thin cuticle-like 5-7,9-11)
endoearp. Inner mesocarp predominantly of Lectotype. NMVP53987; Mueller, 1874a,PI. X, fig. 8;
vertically aligned vasculature surrounded by fFriugist,251-230mhmerelionn.g,On11e mvamlvewiofdegl(odboorsseivuennitlroaclullya)r,
fibre sheaths in a ground mass ofparenchyma; stalk inserted into basal depression. Pericarp wall
at or near inner/outer interface of mesocarp 2-3 mm thick; seedattached apically, with remnants
the vascular bundles branch radially; outer of seed coat loosely adherent to pericarp in basal
mesocarp composed of the radially directed halfoflocule.
vascularbranchesandsurroundingfibresheaths. Type locality. Nintingbool, (Crucible Co.Shaft, -23.2
Preserved seedcoatcomprisesexotestaofa thin, m) near Haddon, SW of Ballarat, Victoria; basal
structurelesscuticle,anendotestalcuticlebearing sediments of a sequence beneath basalt: Oligocene-
Miocene.
impressions of polygonal-shaped transfer cells
(40-60 pm diameter) having internally directed Diagnosis. Fruit woody, indehiscent or tardily
fimbriae, and a tegmic cuticle with impressions dehiscent, spheroidal, unilocular, with 1 seed.
of anticlinal walls of rectilinear cells (55-70 pm Stalk 2-2.5 mm in diameter, inserted into basal
long, 20-25 pm wide). depression 4-5 mm in diameter; style base
152 MemoirsoftheQueensland Museum Nature • 2010 • 55(1)
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1
Fossil Proteaceousfruits
FnIoGvS1177,-3I0ntEeurrioerkasuwreflaccoemsenosfisopsep.nenodv.frauintdwEiutrhekparetsuergnitdead(Fs.eeMudel(la.r)rocwoemdb),,nQoMv.F;5117-12448,;Esucraelkeabwaerlc=o5memnmsi;ss1o8.,
19 Internal and external surface,showingstylebase (arrowed),ofonevalveofopened fruitQMh5114/;scale,
bplaoav'lrey=rgoo5fnmaslem-e;sdh2ca0o,paeCtduatstircvalineseofwfeerfducenulilncsdl,eeQraNnl&idg5hsUte5ead0nd;cossacctaaalntenibbnaasgree=loef1c0ste0reodpn,mm;QiMc2r3F,o5s21c4o,1p5Oe0us;t,seccruatllieacybleearrsoh=fo1ws0ei0endpgmci;omap2t1r,eass2s2v,iioIennwsneeodrt
uisumltnnmladrul;esk2tr25(rs9-al),2ti6aeg3,dnh0t,dEbuSyasrenteMedikudgaesmlcctlaouaear(nrtgsn,ti)tidNinaasMgns(VuFde.ePl,rM5eoeuc3uemt9ltrn8leoa.rn7n);tamcsnisocdcomrafboilsn,seencbneeoaordprvel.c=s,ao2,yal.etec5ruc(smttaiorrmcterl;ysoeppwe2e)s,8c,h,tioNinDwvMteeetiVrlanPiyigol5rN3eoMsf9luVo8prPne7fg5ra;aic3tces9easc8raco7plefel;wlobsaps,alcerlQanlM-Nee2FMd.b5V5af1Prr1mu5i-5m3t09,1s;08h27sop7c;,wmai.Llseneceagblaeotrrtbayacprees1-a0ts0o
153
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Dettmann & Clifford
represented by an ellipsoidal groove, the Diagnosis.Fruitwoody,asymmetricallyprolate
mm
long axis 2-3 and oriented transverse to ellipsoidal, near-smooth externally, unilocular,
the dorso-ventral plane on lateral surface of 1-seeded; indehiscent or tardily dehiscent,
valves; groove underlain by vascular strands dehiscingfromtheapexalongthesinuous,ridged
that extend into the pericarp and terminate ventralsuture. Stalkscarindistinctorvisible, 0.5-
mm
near the seed cavity. Pericarp with a near- 1.5 in diameter, inserted at base; style base
mm
smooth outer surface; wall 2.5-3 thick in indistinct, apical, underlain by vascular strands
mid regionsoflateral surfaces, taperingto1.5-2 thatextend intothe pericarpand terminate near
mm mm
at base of style; composed of thin exocarp the seed cavity. Pericarp wall 2-2.5 thick
overlying a thick vascularised mesocarp and a in mid regions of lateral surfaces, thickening to
mm
thin cuticle-like endocarp. Mesocarp a dense 2.5-3.5 at base of style; composed of thin
groundmass of fibre sheaths that surround the exocarp overlying a thick radially vascularised
vasculature and are predominantly aligned in a mesocarp and a thin cuticle-like endocarp.
mm
radial direction. Preserved seed coatcomprises Mesocarp 1.8-2.2 in thickness in mid
exotesta of a thin, structureless cuticle, an regionsoflateralsurfaces,composed ofa dense
endotestal cuticle bearing faint impressions of groundmass of fibre sheaths that surround the
polygonal cells (40-50 urn in diameter) having vasculature and arranged predominantly in a
occasional internally directed fimbriae, and a radial direction. Preserved seed coatcomprises
tegmic cuticle with impressions of anticlinal exotesta of a thin, structureless cuticle, an
walls of rectilinear cells (80-120 pm long, 20-25 endotestal cuticle bearing faint impressions of
pm wide). polygonal cells (40-50 pm in diameter) having
occasional internally directed fimbriae, and a
Dimensions. Pericarp (2 specimens); vertical tegmic cuticle with impressions of anticlinal
axis 11, 12 mm, dorsiventral axis 10, 11 mm. walls ofrectilinear cells (80-120 pm long, 20-25
pm
wide).
Comparison. E. turgida is smaller and the
pericarpwallisthinnerthanthatof£.welcomensis. Dimensions. Pericarp (8 specimens); vertical
Moreover, the latter species lacks a basal axis 10 (11.8) 14 mm; lateral axes 8 (9.8) 11 mm
depression as occurs in E. turgida. (in plane of dehiscence) x 7.5 (8.4) 10.5 mm (at
right angles to dorsal-ventral plane).
Distribution and age. Known only from the
type lbcality: Oligocene-Miocene. Derivation of name. Named in honour
of Raymond Louis Specht, distinguished
Species- Eureka spechtiisp. nov. (Figs 31-51) Australian ecologist.
1874aConchothecaturgidaMueller,p.42;Pl.X,5-7,9-11 (non
figs8,12) Comparison. E. spechtii differs from E. turgida
Holotype. (heredesignated) NMVP53958 (Mueller, in shape (prolate ellipsoidal vs. spheroidal),
1874a, PI. X , fig. 7), Figs 31-34 herein. Whole fruit, wall thickness (thickest vs thinnest in apical
unilocular, ellipsoidal, vertical axis 13.5 mm, lateral regions) and the ventral suture line (sinuously
axeseach 10.5 mm.Stalkscar3 mm.
ridged vs. straight).
Other material. NMVP52980, NMVP53096,
NMVP53098, NMVP53960,QMF13208. Distribution. Nintingbool(Mueller,1874a,1874b);
Typelocality.Nintingbool,(CrucibleCoShaft,-23.2m) Foster (Deane, 1925), Victoria; Brandy Creek
nearHaddon,SW ofBallarat, Victoria; basal sediments (Johnston1880),Tasmania; Darling Downs (see
ofa sequencebeneath basalt: Oligocene-Miocene. Johnston 1880, p.27), Queensland.
154 Memoirsofthe Queensland Museum Nature • 2010 • 55(1)
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Fossil Proteaceousfruits
Agerange. EarlyOligocene-early Late Miocene. Remarks and Comparison. The holotype and
all butoneoftheotherspecimensexamined are
Species - Eurekaharslettiaesp. nov. charcoalified and their internal morphological
(Figs52-64) and anatomical features are preserved. The
sole permineralised example studied is known
5H3o.lWohtoylpeefr(uhiet,reunidleoscuilganr,ateelldi)ps.oQidMaFl5,1ve1r5t3i,calFiagxsis5129- only from its external morphology. The species
mm, lateral axes each 15.5 mm. Stigma scar 2.5 mm issimilarinsizeto E. welcomensis,but isdistinct
wide at apex , taperingalong its length (7.5 mm) on in possessing a prominent ridge that encircles
both lateral surfaces. the fruit along the ventral suture and dorsal
Other material.QMF51154-QMF51157inclusive. hingeline. Moreover, theV-shaped grooveofthe
Type locality. South Blackwater Coal Pty Ltd Hole stigma scaris longer than that in E. welcomensis.
R8736, 82m,Queensland: Early-LateOligocene.
Distribution. South Blackwater Coal Pty
Diagnosis. Fruit woody, indehiscent or tardily Ltd Hole R8736, 82 m; Glencoe Station, near
dehiscent, with a near-smooth surface; prolate Capella, Queensland.
ellipsoidal to subspheroidal with a prominent
mm Age range. Early-Late Oligocene.
ridge (2-3 high) that encircles the stone in
the longitudinal plane and situated along the
ventral suture and dorsal hinge line; unilocular, AFFINITIESOF EUREKA
1-seeded. Stalk attachment basal, inconspicuous;
style base represented by a V-shaped groove Pericarp vasculature of Eureka is consistent
with thatoffruitsbornebyseveralgeneraofthe
oriented perpendicular to the dorso-ventral
plane and extending 7-9 mm from apex on Proteaceae included within tribe Macadamieae,
and in particular by members of subtribes
lateral surfaceofeach valve; groove widest (1.5- Macadamiinae, Gevuininae, and Virotiinae
2.5 mm) at apex; underlain by vascular strands
(sensu Weston and Barker, 2006; Mast et al.,
thatextend into thepericarpand terminatenear
mm 2008). The pericarps of genera included within
theseed cavity. Pericarp wall 4-6 thick, but
these subtribes possess a complexly branched
thinning slightly around base of style; mostly
vascular system surrounded by sclerenchyma
composed ofvascularised mesocarpexternal to
and/orfibresheathsand/orstonecellcomplexes.
a thin, cuticle-like layer (?endocarp). Mesocarp
mm The main vascular bundles are predominantly
3.S-5.8 in thickness, composed of a dense
vgarsocuunldarmamsesshofafnibdrearsehepartehdsotmhiantasnutrlryoaulnidgntehde vreergtiiocnalolfytahleimgenesdo,caorcpc,urarnidngexwtietrhnialnttoheanmairdrdolwe
zone of parenchyma and/or sclereids of the
ina radial direction.Seedcoatcomprisesexotesta innermost mesocarp. The vertical bundles
ofa thin unstructured cuticle, and an endotestal branch radially, the radial branches extending
cceultliscl(e4b0e-a50ripngmfaiinntdiiammperteesrs)iohnasviofngposlpyagrosneally into the outer region of the mesocarp where
they are sheathed by sclerenchyma; the tissues
distributed, internally directed fimbriae.
between themarecomposed offibres, stonecell
Derivation of name. Named in honour of complexesand/or thin-walled (and sometimes
MorwennaJean Harslett,Queensland naturalist. succulent) parenchyma. Thus, the middle region
of the pericarp with its vertically aligned,
Dimensions. Pericarp (12 specimens); vertical sheathed vasculature is densely structured
axis 15 (16.7) 21 mm; lateral axes 13 (15.5) 21 and may be woody and endocarp-like,
mm mm
(in plane of dehiscence) x 8 (11.8) 15 whereas the outer region of the pericarp is
(at right angles to dorsal-ventral plane). predominantly radially structured (Figs 65-68,
MemoirsoftheQueensland Museum Nature • 2010 • 55(1) 155
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Dettmann & Clifford
FIGS31-41. Eurekaspechtiisp.nov. 31-34, Holotypeinlateral (31,32),apical (33),and basal (34) viewsshowing
dorsalsuture(ds)andstalkscar(s), \'MVP53598;scalebar=2.5mm;35-37,External (35)and internal (36,3/)
viewsofpericarp showingstyle base (arrowed) and apically attached seed (arrow), NMVP53096; scale bar
= 2.5 mm; 38-39, Seed illustrated in Fig. 37 before (38) and’after (39) treatment with sodium hypochlorite
showing positions ofchalaza (ch) and micropyle (m), NMVP53096; scale bar = 1 mm; 40, Transfer cells of
seedcoatofholotype, NMVP53598;scalebar=10pm.
156 Memoirsofthe Queensland Museum Nature • 2010 • 55(1)
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