Late Tortonian bryozoans from Mut Basin, Central Anatolian Plateau, southern Turkey

13 Pages·2013·1.06 MB·English

Late Tortonian bryozoans from Mut Basin,
Central Anatolian Plateau, southern Turkey
KAMIL ZÁGORŠEK and DENNIS P. GORDON
Zágoršek,K.andGordon,D.P.2013.LateTortonianbryozoansfromMutBasin,CentralAnatolianPlateau,southern
Turkey.Acta Paleontologica Polonica58 (3): 595–607.
SixteenbryozoanspecieshavebeenidentifiedintheBaşyaylasection,MutBasin,southernTurkey.Fiveofthesespecies
are described here, including two new to science representing new genera: Basyaylella elsae gen. et sp. nov. and
Ostrovskia triforamina gen. et sp. nov. The other three described species (Exidmonea sp., Biflustra savartii, and
Margarettasp.)showunusualfeaturesthathavenotbeenreportedpreviously.Basedonbryozoandata,theBaşyayla
sequencerepresentsatropicaltosubtropical,normalmarineenvironment,withseafloorcomposedoffinesedimentary
particles in a low−energy setting.
Key words: Bryozoa, Cheilostomata,Basyaylella,Ostrovskia, Tortonian, Eocene, Miocene, Mut Basin, Turkey.
KamilZágoršek[[email protected]],DepartmentofPaleontology,NationalMuseum,Vaclavskénam.68,CZ−115
79 Prague 1, Czech Republic;
DennisP.Gordon[[email protected]],NationalInstituteofWater&AtmosphericResearch,PrivateBag14901,
Kilbirnie, Wellington, New Zealand.
Received 14 July 2011, accepted 13 January 2012, available online 17 January 2012.
Copyright©2013K.ZágoršekandD.P.Gordon.Thisisanopen−accessarticledistributedunderthetermsoftheCreative
CommonsAttributionLicense,whichpermitsunrestricteduse,distribution,andreproductioninanymedium,provided
the original author and source are credited.
Introduction rocks. The maximum thickness of these undeformed Mio−
cene marine sediments is about 2000 m (Cosentino et al.
2010).
The Central Anatolian Plateau (CAP) formed as a conse−
The Başyayla section is situated close to the town of
quenceofalongandcomplexdeformationalhistory,mainly
Başyaylaandshowsabout40mofoffshoremarlswithabout
owingtotheconvergencebetweentheArabianandEurasian
20 m of sediments transitional to the shallow−water lime−
plates. Pontide and Taurides orogenic belts bounded the
stone at the northern margin of the Mut−Ermenek Basin.
northernandsouthernmarginsoftheCAP.Anintramontane
extension, initiatedthroughout theTauridesduringtheLate RecentstudieshavegivenaLateTortonianage,basedon
Eocene–Early Miocene, produced tectonically controlled the ostracods Semicytherura velata and Cytherella vulgata
sedimentary basins including, among others, the Mut− (Gliozzi et al. 2010) and the foraminiferan Globigerinoides
ErmenekBasinonthesouthernmarginoftheCAP(Aksuet extremus–GloborotaliasuteraeIntervalSubzone(MMi12a)
al.1992;Görür1992).TheepicontinentalMut−ErmenekBa− that ranges from 8.35 to 7.81 Ma (Cosentino et al. 2010).
sin was predominantly filled by marine sedimentary se− Paleontologicalanalyseswereperformedon25samples,
quencesofOligocene–EarlyMioceneage,correspondingto spacedmoreorlessregularlyevery50cmalongtheclayey−
the Burdigalian–Serravallian TB2 supercycle of Haq et al. marly sediments cropping out in the two studied Başyayla
(1988). successions(GPS36(cid:2)46’1.084”N,32(cid:2)40’55.309”E),rang−
Themarinedepositsaremainlymarlswithintercalations ingfrom1781ma.s.l.atthebaseto1839ma.s.l.atthetop
of carbonates, laterally transitioning to carbonate ramp de− (Gliozzi et al. 2010). Bryozoans were found in 22 samples.
positssuch asbryomol, foramol and/or rhodalgal limestone Altogether 16 species have been identified. Volumetrically
(Mandic et al. 2004; Eriş et al. 2005; Şafak et al. 2005; the commonest species are free−living bryozoans of the ge−
Jansonetal.2010).Thedepositsareusuallyundeformedand nus Reussirella, occurring in 17 samples. Free−living colo−
subhorizontal throughout the Mut−Ermenek Basin. In the niesofCupuladriaarealsoveryabundant,asareerect−rigid
Başyayla area, the uppermost part of the Miocene marine branchesofBasyayellagen.nov.andnodesoferect−flexible
succession of the Mut−Ermenek Basin covered Mesozoic Nellia, occurring in seven to eight samples.
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596 ACTA PALAEONTOLOGICA POLONICA 58 (3), 2013
Table 1: List of all determined taxa with their occurrences within the Başyayla section.
Taxa/samples BAS 1 2 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Biflustra savartii     1       1 1             1           1  
Cellariacf.fistulosa 1   1   1 1   1       1       1            
Crisia haueri 1                       1     1     1 1   1
Cupuladriasp.     1 1 1         1       1   1 1         1
Exidmoneasp.   1                                       1
Basyaylella elsaesp. nov. 1 1 1   1 1       1       1 1     1        
Idmidroneasp. 1 1                                       1
Lunulitescf.androsaces         1             1                    
Margarettasp.   1 1   1 1 1 1   1   1 1         1        
Nelliacf.tenella                       1 1 1 1 1   1 1 1    
Pleuronea pertusa                                           1
Reteporellasp.     1   1           1                   1  
Reussirella haidingeri 1 1 1 1 1   1 1 1 1 1 1 1 1 1 1 1 1     1  
Ostrovskia triforaminasp. nov.   1 1                                      
Schizostomella grinzingensis     1         1       1     1           1  
Steginoporella montenati                                         1  
Number of species 5 6 9 2 7 3 3 5 1 4 2 6 4 4 5 5 2 4 2 2 5 5
Remarkably,twonewmonotypicgeneraofCheilostomata seum,Prague,CzechRepublic.Thisinstrumentallowedback−
are recognised in the samples, both incertae sedis and unre− scattered electron images to be obtained of uncoated speci−
lated.OnegenusissuperficiallysimilartotheNorthAmerican mens temporarily mounted to stubs using adhesive carbon
genus Enoplostomella (putatively Stomachetosellidae) and tabs,oraffixedtostagemountswithcarbonplastic.
theopportunityistakenheretocommentonthestatusofthis
genus. The other genus is a probable member of the super−
family Schizoporelloidea but has distinctive morphological Systematic paleontology
features that confound exact taxonomic placement. We dis−
cuss these new and little−known taxa and the novel morpho−
Allofthebryozoans found intheBaşyayla section taxa are
logicalfeatures.
listed in Table 1. New taxa and material with notable mor−
We present evidence, based on taxonomic composition phological features are described or commented on below.
andcolonialmorphology,thatthepaleoclimatewastropical
to subtropical, and that the paleoenvironment was that of a Phylum Bryozoa Ehrenberg, 1831
well−consolidatedseafloor,withthepresenceofsmallparti−
Order Cyclostomata Busk, 1852
cles and low water energy in a fully marine setting.
Suborder Tubuliporina Milne Edwards, 1838
Institutional abbreviations.—PM2, Natural History collec−
Family Tubuliporidae Johnston, 1838
tion,NationalMuseum,Prague,CzechRepublic;T,foreign
Tertiary collection within PM2. Genus Exidmonea David, Mongereau, and Pouyet,
1972
Otherabbreviations.—CAP,CentralAnatolianPlateau;TB2,
Type species: Exidmonea atlantica David, Mongereau, and Pouyet,
Haq et al. (1988) supercycle; TEM, transmission electron
1972(seeJohnston1847andalsoBragaandBarbin1988;Taylorand
microscope.
Voigt 1993; Florence et al. 2007); Miocene of Paris Basin.
Diagnosis.—Colony erect, rarely bifurcating. Branches rod−
like,ovaltotriangularintransversesection.Autozooecialap−
Material and methods
erturesarrangedinparallelfascicles.Gonozooeciasituatedon
the frontalside, globularwith an ooeciopore smallerthan an
All material came from the collection of Elsa Gliozzi (Uni− autozooecialaperture.Nokenozooeciaonthedorsalside.
versitàdegliStudi,Roma,Italy),whocollecteditinthefield
Exidmonea sp.
andkindlypresentedthecollectiontothefirstauthorforstudy.
Fig. 1A.
Thematerialwaswashedandsieved,thensortedunderabin−
ocularmicroscope.Wellpreservedand/orovicellateexamples Material.—Onefragment(PM2−T1124)ofalargebifurcat−
ofeachspecieswerecleanedultrasonicallyandstudiedusinga ing colony with the gonozooecium extending across ten
low−vacuum LV HitachiS−3700N SEM atthe NationalMu− autozooecial fascicles.
ZÁGORŠEK AND GORDON—MIOCENE BRYOZOANS FROM TURKEY 597
A B C D E F
G H
I
Fig.1.LateTortonianbryozoansfromtheBaşyaylasection.A.Exidmoneasp.(PM2−T1124)withveryextendedfrontalgonozooeciumfromsampleBAS
2.B–E.Biflustrasavartiiauctt.B.PM2−T1127,frontalviewofcolony,sampleBAS8.C.PM2−T1126,abfrontalviewshowingthreerowsofautozooecia
withcharacteristicangledappearance,sampleBAS8.D.PM2−T1125,lateralviewofthethreeautozooeciashowingregularlydistributedlateralcommuni−
cationpores,sampleBAS4.E.PM2−T1129,detailoflateralcommunicationporesshowingmultiporousseptula,sampleBAS4.F–H.Margarettasp.
F.PM2−T1130,externalviewshowingconcealedovicells(visibleasbulgesinfrontalshield),sampleBAS8.G.PM2−T1131,internalviewshowing
peristomialchamber,withanascoporesituatedinthemidlineofthefrontalshield,sampleBAS11.H.PM2−T1132,detailoftheapertureofacolonyshow−
inglinearstructuresintheperistomialwall,sampleBAS7.I.Margarettacereoides(EllisandSolander,1786)(PM2−P1939)fromsectionHlohovec
(Moravia) showing the smooth interior surface of the peristome. Scale bars A, B, F, 1 mm; C–E, G–I, 100 μm.
Remarks.—TheTurkishspecimenverymuchresemblesExid− similartothespecimendescribedbyHaywardandMcKinney
moneaatlanticaDavid,Mongereau,andPouyet(1972)asil− (2002: fig. 49H) as Exidmonea triforis (Heller, 1867) from
lustrated by Zágoršek (2010a) from Moravia. However, the RovinjintheAdriaticSea,whichwasneverreportedfromfos−
size and shape of the gonozooecium is much smaller in the sil sequences. The gonozooecium is unusually large for any
Moravian material (extending only across five autozooecial fossil known species. Because only one specimen has been
fascicles). The size and shape of the gonozooecium is very found,theexactdeterminationremainsuncertain.
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598 ACTA PALAEONTOLOGICA POLONICA 58 (3), 2013
Order Cheilostomata Busk, 1852 Suborder Ascophora Levinsen, 1909
Suborder Malacostegina Levinsen, 1902 Incertae sedis
Superfamily Membraniporoidea Busk, 1852 Genus Basyaylella nov.
Family Membraniporidae Busk, 1852 Type species:Basyaylellaelsaesp. nov.; see below.
Etymology: Alluding to the name of the Başyayla section.
Genus Biflustrad’Orbigny, 1852
Diagnosis.—Colonyerect,rigid,brancheswithcircularcross
Type species: Flustra ramosa d’Orbigny, 1852; Recent, Manila Bay
sections. Up to five rows of autozooecia around branch, ab−
Philippines. For details see Tilbrook (2006).
frontal side without orifices, formed by dorsal sides of mar−
Diagnosis.—Embedded from Tilbrook (2006): Colony en−
ginal rows of autozooecia. Autozooecia with areolar pores,
crustingorerect,foliaceous,orvincularianfromanencrust−
frontal pseudopores and central nonporous area on frontal
ing base. Autozooecia with well−developed cryptocyst and
shield as viewed from exterior. Orifices circular with thick,
nospines.Opesiausuallyverylarge.Gymnocystnotdevel−
widebutshortperistome.Primaryorificewithoutsinus,sec−
oped. Ovicell unknown. Avicularia lacking.
ondary orifice may have a pseudosinus. Avicularia adventi−
Biflustra savartiiauctt. tious, situated on proximal part of autozooecia, on frontal as
wellonabfrontalsideofcolony.Ovicellglobularwithperfo−
Fig. 1B–E.
rated entooecium, deeply immersed in distal autozooecium,
1974Biflustra savartii(Audouin, 1826); David and Pouyet 1974: 99.
butnotfrontallypronounced.Kenozooeciapresent.
1988Biflustra savartii (Audouin, 1826); Moissette 1988: 73, pl. 11,
fig. 6. Remarks.—ThefrontalshieldofBasyaylellaisperhapsmixed
(umbonuloid and lepralioid), and therefore the family and
Referred material.—Altogether eight specimens were stud−
eventhesuperfamilyrelationshipsareuncertain.However,it
ied(fourofthemillustratedPM2−T1125toPM2−T1127and
mayhaveaffinitieswithsomegeneratraditionallyclassifiedin
PM2−T1129),mainlywithsmoothdorsalwallsandwell−pre−
theStomachetosellidae.Thisfamilyisitselfsomewhathetero−
served lateral communication pores.
geneous and badly needs revising, and the type species of
Remarks.—This species is frequently listed under the genus
StomachetosellaisanOligocenefossil,butletusconsiderthe
Biflustra, however the type species of Biflustra (Recent
potentialcandidategenera,eachbasedonitstypespecies:
Biflustra ramosa d’Orbigny, 1852 from the Philippines) is
– Stomachetosella crassicollis Canu and Bassler, 1917,
knownonlyfromasinglespecimenthatlackstheancestrular
Early Oligocene, Mississippi, has erect bilamellar/flabel−
region.Thereforeitisnotknowniftheancestrulaistwinnedor
late fronds to subvincularian stems in which the zooids,
single. The type species of Acanthodesia is Flustra savartii
openingonallsides,havearegularlyperforated,pseudo−
andTaylorandFoster(1998)prefertoretainthisgenuspend−
porouslepralioidfrontalshield.Theorificehasatapering
ingdescriptionoftheancestrulaofB.ramosa.
rounded poster and condyles appear to be lacking. Ovi−
The frontal features of studied specimens are identical
cellsarehyperstomialandporous,somewhatlikethefron−
with those described by Zágoršek (2010a) from the Mora−
tal shield, and there are no avicularia.
vian Miocene (Fig. 1B) as Biflustra savartii. The abfrontal
– Enoplostomella defixa Canu and Bassler, 1917, Late
side of the zooids is very smooth, giving evidence that the
Eocene–Early Oligocene, Alabama, has erect cylindrical
colonywasoriginallybilamellarandthetwolayershavesep−
stemswithzooidsopeningallaround.Thefrontalshieldin
arated (Fig. 1C). Lateral walls are perforated by well−pre−
frontal view appears more or less evenly pseudoporous.
serveduniporousandmultiporousmuralseptula(communi−
Theorificedevelopsathickenedperistomialriminwhich
cationporeareas),lackinginMoravianmaterial(Fig.1D,E).
anaviculariumissetononesideofthesinus.Ovicellsare
TheprecisetaxonomicstatusofthespeciesFlustrasavartii
conspicuous, hyperstomial, and evenly porous, and a
Audouin (1826) and the various forms attributed to it have
well−developedadventitiousaviculariumissetintheperi−
yettoberesolved,althoughTaylorandFoster(1998)figured
stomial rim on one side of the orifice.
aputativespecimenofFlustrasavartiifromthetypeareaof
– Metrocrypta bucculenta Canu and Bassler, 1917, Late
theRedSea.Forthisreasonourspecimensarereferredtoas
Eocene,NorthCarolina,hasdichotomouslybranchingcy−
A. savartiauctt.
lindricalstemswithzooidsopeningallaround.Zooidsare
Stratigraphic and geographic range.—Miocene to Recent, more or less evenly pseudoporous and, with secondary
cosmopolitan. calcification, the interzooidal boundaries become indis−
Fig.2.ExteriorviewofanascophoranbryozoanBasyaylellaelsaegen.etsp.nov.fromtheMioceneofTurkey.A.PM2−T1218,paratypeshowingageneral (cid:3)
viewofthecolony.B.PM2−T1217,holotypeshowingsecondaryorificesandaviculariaontheautozooecialfrontalshield.C.PM2−T1219,abfrontalview
showingaviculariumwithobviouspivotbar.D.PM2−T1220,frontalviewshowingautozooeciawithperistomialsinus.E.PM2−T1221,abfrontalsideofa
colony fragment. F. PM2−T1222, basal part of a colony with the attachment point and an elongated kenozooecial surface on the abfrontal side.
G.PM2−T1223,frontalviewofless−calcifiedcolonyshowingdistributionofmarginalareolarpores.H.PM2−T1224,detailofautozooecialsecondaryori−
ficeswithpseudosinusesandsmallheterozooecia.I.PM2−T1225,abranchfragmentshowingkenozooeciaintheareaofthebifurcation.Allspecimens
from sample BAS 4. Scale bars A–E, G, I, 1 mm; F, H, 100 μm.
ZÁGORŠEK AND GORDON—MIOCENE BRYOZOANS FROM TURKEY 599
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E F G H
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600 ACTA PALAEONTOLOGICA POLONICA 58 (3), 2013
tinct.Primaryorificesaredeeplyconcealedanddescribed alsolacksaperistomialavicularium,whereasithasrelatively
as “orbicular”, i.e., lacking a sinus; secondary (peristo− large interzooidal avicularia, lacking in E. vallata and E.
mial)orificesaremoreorlessroundandraisedabovethe magniporosa. On the other hand, ovicells in the latter two
zooidalsurface.Smalladventitiousaviculariaarelacking speciesareconcealedbysecondarycalcification(exceptdis−
butCanuandBassler(1917)describedaverylargelatero− tallyinyoungzooidsinE.magniporosa),justasinourspe−
frontal avicularium suborally that occupies much of the cies.The“apertura”,i.e.,theprimaryorifice,inE.vallatais
frontalwall.Definiteovicellshavenotbeenidentifiedbut described as “semilunar with a straight proximal border” in
rarelarge,round broken chambers distaltosomeorifices E.vallataandsuborbicularinE.magniporosa;inourspecies
could be ovicell chambers, in which case they would be the primary orifice lacks a sinus.
described as hyperstomial and prominent in life. Onbalance,weconcludethatourspeciesdifferssignifi−
– Ochetosella jacksonica Canu and Bassler, 1917, Middle cantlyfromthetypespeciesofEnoplostomellatowarranta
Eocene, Alabama, to Late Eocene, Mississipi and south− newgenus.Ontheotherhand,itappearshighlylikelythatE.
easternUSA,likewisehascylindricalbranchingstemsbut vallataandE.magniporosaarenotcongenericwithEnoplo−
thefrontalshieldisnon−pseudoporous,withonlymarginal stomella. We cannot say, without detailed examination of
areolarpores.Interzooidalboundariesareraisedinyoung these species, if they may be included in Basyaylella.
zooids but become indistinct in older zooids. There is a
Geographicandstratygraphicrange.—LateTortonian,Başy−
large laterofrontal avicularium suborally in some zooids.
aylasection
Ovicellsaresubglobular,smooth−surfacedandrecumbent.
– Metradolium dissimile Canu and Bassler, 1917, Late Basyaylella elsae sp. nov.
Eocene, southeastern USA, has flattened bifurcating
Figs. 2, 3.
branches with parallel sides and zooids opening all
Etymology:InhonourofProfessorElsaGliozzi,whoprovideduswith
around. The frontal shield is convex and evenly pseudo−
thesamplesandwhohasbeenstudyingtheBaşyaylasectionindetailfor
porouswithindistinctzooidalboundaries.Theprimaryor−
many years.
ificeisdeeplyconcealed andsuborbicular;thesecondary
Typematerial:Holotype:PM2−T1217(Fig.2B),sampleBAS4.Para−
orificetendstobewiderthanlongandisroundedwithout
types:PM2−T1218toT1229,12specimens,samplesBAS4,6,7,and19
aprojectingperistomialrim.Adventitiousovalavicularia (Figs. 2, 3).
mayoccurjustproximalofthecornersoftheperistomial
Type locality: Başyayla section, Turkey.
orifice,singleorpaired,withonetypicallylargerthanthe
Type horizon: Upper Tortonian, Miocene.
other. The ovicell is concealed and opens into the peri−
stome; it is visible externally as a bulge. Referred material.—22 additional colonies (two of them il−
Of the above genera, Ochetosella can be quickly ruled lustrated (Fig. 3B, F) PM2−T1159 and PM2−T1160) were
out. Although some individual zooids in Basyaylella gen. studiedfromsamplesBAS7,13,14,and19undertheSEM,
nov.canresemblezooidsofOchetosella(seethedistalmost but not included into the type collection.
zooidsinFig.2G),thespecieshasamostlyfrontallyporous
Diagnosis.—As for the genus.
shield,whichisnotthecaseinOchetosella.Inthetypespe−
ciesoftheotherfourgenera zooidsopen onallfacesofthe Description.—Colonyerect,rigid,branchesbifurcating(Fig.
stems and the frontal shields are externally evenly pseudo− 2A) with autozooecia opening on three sides. Branch cross
porous. In details of form and placement of avicularia and section circular, no median lamella developed. Attachment
ovicells,thesethreegeneradonotappearcloseenoughtoour pointwide,rigid(Fig.2F).Frontalpartofbranchwithupto
newspeciestoincludeitinthescopeoftheircharacters.On five rows of autozooecia (Fig. 2A, B), abfrontal side with
theotherhand,whatisknownaboutthecharactersoftwoof sinuous,slightlyzigzagpatternofattachmentoflateralwalls
thespeciesascribedbyCanuandBassler(1917)toEnoplo− (Fig. 2C–E).
stomellainvitescomparisonwiththisgenus.Enoplostomella In external view, autozooecia elongated, separated by
vallata and E. magniporosa have dichotomously branching narrow furrows.Frontalshieldofless−calcifiedautozooecia
stemswithdistinctfrontalandabfrontalfaces,with3–4lon− apparentlywithareolarporesonly(Fig.2G)andlargecentral
gitudinal rows of zooids opening mostly frontally and two nonporousarea.Later,thenonporousareabecomesreduced,
longitudinal rows of dorsal zooidal walls appearing ab− withtherestoffrontalwallstronglyperforated.(Fig.2B–D,
frontally. The dorsal side is relatively coarsely perforated I). Primary orifice circular, semi−oval, with thick, wide but
andtheinterzooidalboundary betweenthetwolongitudinal shortperistome(Fig.2B).Afewsecondaryorificesdevelop
rows of zooids forms a distinctively sinuous line down the a pseudosinus, perhaps during intramural budding, similar
middle.Inthisregard,plate89,fig.18ofCanuandBassler that those described by Berning (2008) (Fig. 2B, D, H).
(1917)showingtheabfrontalsideofE.magniporosagreatly Adventitious(interzooidal?)aviculariasituatedonfrontal
resemblesthearrangementinourFig.2E.CanuandBassler (Fig.2B)andabfrontalsides(Fig.2C)ofbranch,occupying
(1917)presentednoillustrationsofthezooidalinteriorsinE. proximalpartofautozooecialfrontalwall(Fig.2B,H).Pivot
vallataandE.magniporosaandthereisthusnoevidencethat bar well developed, rounded rostrum palate tapering proxi−
eitherofthesespecieshasamixedfrontalshield.Ourspecies mally (Fig.2B, C). Ovicells not observed on branch exteri−
ZÁGORŠEK AND GORDON—MIOCENE BRYOZOANS FROM TURKEY 601
A B C
D E F
Fig.3.InteriorviewofanascophoranbryozoanBasyaylellaelsaegen.etsp.nov.fromtheMioceneofTurkey.A.PM2−T126,detailshowingpartofacon−
cealedovicellchamber(broken)andthereducedumbonuloidpartofthefrontalshield.B.PM2−T1159,autozooecialprofileswithclearlyobservable
umbonuloidpartofthefrontalshield,smoothperistome,largepseudoporesandlaminationsinfrontalshield.C.PM2−T1227,detailofalaterallybroken
specimenwithwellpronouncedlaminationsinfrontalshieldandasmoothperistome.D.PM2−T1228,interiorviewshowingbroken,concealedovicellular
chambers, deeply immersed in distal autozooecia. E. PM2−T1229a, similar view to D and also showing the umbonuloid part of the frontal shield.
F. PM2−T1160, detail of ovicell interior with entooecial perforations. A, C, D, E sample BAS 4; B, F sample BAS 7. Scale bars 100 μm.
ors. Kenozooecia often present in branch bifurcations (Fig. umbonuloidpartelongatedsemicircular,smallwithcharacter−
2I) or on abfrontal side (Fig. 2F). istic microstructure (Fig. 3B, E) and ring scar (Fig. 3A, B,
Ininternalviewsautozooeciaclearlyseparatedbyfurrows D–F).Thelepralioidpartperforatedbyverylargepores(Fig.
with mixed (umbonuloid and lepralioid) frontal shield. The 3B–F). Marginal areolar pores visible only near orifice (Fig.
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602 ACTA PALAEONTOLOGICA POLONICA 58 (3), 2013
3B,F).Primaryorificecircularwithslightlystraightproximal tudinalrows,ofindistinctshapeowingtodenselyperforated
margin (Fig. 3A, D) and sometimes with median ridge (Fig. slightlyconvexfrontalwall(Fig.1F).Secondaryorificecir−
3B,E).Peristomelong,smooth(Fig.3B,C).Parallellongitu− culartooval,noexternalperistomeobserved.Ascoporenot
dinal furrows evident in sides of separated adjacent frontal observable from exterior. Ovicell deeply immersed, peri−
shields(Fig.3B,C).Internalwallsthin(Fig.3E). stomial (Fig. 1F). Interior view shows regular small frontal
Ovicells deeply immersed in distal autozooecia (Fig. 3A, pores(Fig.1G)andmedian,circular,slightlylargerascopore
D–F), not pronounced on external surface; ovicells globular (Fig. 1G); peristome consisting of 5–8 longitudinal bands
(Fig.3F),visibleonlywhenzooidsarefracturedandviewed separatedbynarrow,butdistinctfurrows(Fig.1G,H).Ovi−
from interior (Fig. 3E); entooecium perforated by pores of cell not observed in interior view.
samesizeasfrontalpseudopores(Fig.3A,F),ectooeciumnot
Remarks.—Margaretta cereoides (Ellis and Solander, 1786)
observable. A narrow wall developed between autozooecial
as described from the Miocene of Moravia by Zágoršek
orificeandovicellchamber(Fig.3A,F).
(2010b:154,pl.109:1–4)doesnothavefurrowsintheperi−
Measurements.—Given in μm, average value in brackets: stomialwallfabric(visibleinourFig.1J),whichmaybecon−
– width of colony branch: 519–886 (682) in bifurcation up sideredaspecies−specificfeature.However,arevisionofthe
to 1270 Margarettidaewouldbeneededforadefiniteconclusion.
– width of autozooecium (external): 218–399 (310)
– length of autozooecium (external): 503–914 (744) Family Incertae sedis
– width of autozooecium (internal): 170–209 (191)
Genus Ostrovskia nov.
– length of autozooecium (internal): 633–778 (678)
Type species:Ostrovskia triforaminasp. nov., see below.
– width of avicularium: 101–124 (116)
Etymology:ForDrAndreiN.Ostrovsky,inrecognitionofhisilluminat−
– length of avicularium: 238–319 (267)
ing studies on cheilostome reproductive structures.
– width of kenozooecium: 150–252 (201)
Diagnosis.—Colony erect, rigid, narrowly bilamellar,
– length of kenozooecium: 160–378 (269)
branches circular to oval in cross section. Frontal shield
– diameter of orifice (external): 122–167 (150)
evenly pseudoporous with indistinguishable areolar pores.
– diameter of orifice (internal): 99–133 (117)
Primary orifice concealed within peristomial shaft; anter
– diameter of pseudopores (external): 29–41 (36)
semicircular, poster a littlewider, smallcondyles, proximal
– diameter of pores (internal): 21–28 (23)
rimstraightorgentlyconvex,nosinus.Peristomial(second−
– diameter of peristome in section: 160–167 (164)
ary)orificecircular,surroundedentirelybybroadrim,inthe
– width of ovicell (internal): 151–164 (147)
inner proximal margin of which is tiny opening of hetero−
– width of umbonuloid shield: 87–139 (113)
zooecium that originates internally from a pair of areolar
– length of umbonuloid shield: 109–170 (139)
septula. No frontal avicularia. Ovicell concealed, opening
Remarks.—Asnotedabove,therearesomesimilaritieswith
intoperistomeaboveprimaryorifice;entooeciumperforated
two North American species attributed to Enoplostomella
by relatively large pores.
but which are unlikely to belong to that genus.
Thetypeofsubstratecolonized byBasyaylella elsaesp. Remarks.—The family and even the superfamily are uncer−
nov. has not been observed. tain. The mostdistinctive feature of the genus is a triangular
heterozooeciumthatliesagainsttheproximalwallofthedeep
Family Margarettidae Harmer, 1957 peristomial shaft. The apex of the heterozooecium is a tiny
opening that, in the best−preserved specimens, appears as a
Genus MargarettaGray, 1843
smallcircularforamen,butitisoftendamagedand,infrontal
Typespecies:CellariabarbataLamarck,1816;Recent;Australiaand
view,thebrokenedgecanappearasadenticulatestructure.In−
New Zealand.
ternally,thechamberoftheheterozooeciumbroadenstoform
Diagnosis.—Colony erect,articulated.Autozooeciaelongate
aflattenedtriangularshape,withitstubularproximalcorners
with perforated frontal wall and well−defined ascopore. Oral
originatingfromapairofareolarseptularpores.Inthisregard,
spinesandavicularianotdeveloped.Ovicellperistomial.
the topology of the structure is reminiscent of the median
Stratigraphic and geographic range.—Palaeogene to Re− suboral or intraoral avicularium of a smittinid; however, the
cent, cosmopolitan. ovicellisdeeplyconcealedbycryptocystalsecondarycalcifi−
cation,whichisatypicalofsmittinids.
Margarettasp.
AsZágoršek(2010b:155)hasremarkedwhendescribing
Fig. 1F–J.
this species as Phoceana tubulifera (Reuss, 1847), the type
Referredmaterial.—Altogethereightspecimenswerestudied speciesofOstrovskiaresemblesSmittinacervicornis(Pallas,
(three of them illustrated (Fig. 1F–H) PM2−T1130 to PM2−
1766)ingeneralappearance,butonlywhentheperistomeis
T1132), mainly with highly developed secondary calcifica−
notproduced.Inspecimensinwhichaperistomeispresent,a
tion. generalsimilaritytoPhoceanaJullieninJullienandCalvet,
Description.—Colony columnar with branches of circular 1903 has led to previous inclusion in that genus, beginning
cross−section (Fig.1F). Autozooecia arranged in4–8 longi− withDavidandPouyet(1974). Itisdoubtfulifthisconnec−
ZÁGORŠEK AND GORDON—MIOCENE BRYOZOANS FROM TURKEY 603
A B
C D
Fig.4.ExteriorandinteriorviewofanascophoranbryozoanOstrovskiatriforaminagen.etsp.nov.fromtheMioceneofTurkey.A.PM2−T1245,holotype,
exteriorviewshowingarrangementofautozooeciaandthebrokentipsofintra−peristomialheterozooeciavisibleontheproximalmarginoftheorifice,ap−
pearingasdenticles.B.PM2−T1246,interiorviewshowingimmersedovicell,marginalareolar−septularporecanalsinsection,perforationoffrontalwall
andsmallcondylesonthesidesoftheorifice.C.PM2−T1247,detailofautozooeciashowingovicellswithperforatedendooeciumandasmallsuboralarea
ofimperforatefrontalshield.D.PM2−T1134,detailofovicellwithentooecialperforationsand,proximolateraltoitonbothsides,brokenareolar−septular
pore canals. All specimens from sample BAS 4. Scale bars A, 1 mm; B–D, 100 μm.
tion is valid, however. In the type species of Phoceana, P. shield is non−pseudoporous. Very little is known about P.
columnaris Jullien, in Jullien and Calvet, 1903, the frontal columnaris, however, and neither avicularia nor ovicells
http://dx.doi.org/10.4202/app.2011.0100
604 ACTA PALAEONTOLOGICA POLONICA 58 (3), 2013
were described. Phoceana acadiana Lagaaij, 1963, how− and broadening as it descends so that at the level of the pri−
ever, appears tobeconspecific withP.columnaris (Lagaaij mary aperture it occupies the full internal width of the
[1963] was able to examine a specimen of P. columnaris zooecium,itsbasolateralcornerstubular,originatingfroman
fromtheMediterranean) andithasaprimarilynon−pseudo− areolar septulum on each side. No frontalavicularia. Ovicell
porousfrontalshield“withirregularpatchesofwhitetremo− deeplyconcealed,openingintoperistomeaboveprimaryaper−
cyst”; this description suggests that the frontal pores in this ture;endooeciumperforatedbyrelativelylargepores.
speciesmaybederivedfromlateralareolarporesinsecond−
Measurements.—Given in μm, average value in brackets:
arycalcification.Italsohasovicells“lodgedintheacutean−
– width of colony branch: up to 1920
gle between the peristome and the outer wall of the zoarial
– width of autozooecium (external): 311–666 (469)
branch” but Lagaaij (1963) did not illustrate these. Largely
– length of autozooecium (external): 931–1380 (1029)
onthebasisofthefrontalshield,weconcludethatP.tubuli−
– width of autozooecium (internal): 284–407 (335)
feradoes not belong toPhoceana.
– length of autozooecium (internal): 767–1160 (952)
One of the specimens illustrated by Zágoršek (2010b:pl.
– maximal width of heterozooecium (measured from inter−
114:1)hasanovicell.Thisisinazooeciumnearthedistalend
nal side): 122–246 (171)
ofaneanicbranchinwhichsecondarycalcificationisnotso
– minimal width of heterozooecium (measured from exter−
thick.Henceitislikelythatnewlyformedzooidshavearela−
nal side): 45–71 (57)
tivelylongperistomeandovicellsarestillvisibleasabulgein
– diameter of orifice (external): 185–244 (215)
the wall, but, as secondary calcification increases, it rises to
– diameter of orifice (internal): 156–318 (217)
theleveloftheperistomialopeningandtheovicellsbecomes
– diameter of frontal pores (external): 20–37 (26)
deeplyconcealed.Theneanicovicellisneverthelesscovered
– diameter of frontal pores (internal): 6–14 (9)
byacryptocystallayerthatresemblesthepseudoporousfron−
– diameter of peristome in section: 195–216 (208)
tal shield, hence it is “schizoporelloid” rather than “smitti−
noid”. For this reason, assigning Ostrovskia to a particular – width of ovicell (internal): 191–266 (232)
familyisdifficult.Overall,weconcludethatthesuperfamilyis – diameter of ovicell pores (internal): 23–43 (29)
Schizoporelloideasensulato,butcannotsuggestafamily. – diameter of areolar pores (measured from internal side):
18–27 (23)
Ostrovskia triforamina sp. nov.
– thickness of frontal wall in section: 208–356 (258)
Figs. 4, 5.
Remarks.—Inexternalview,ourcoloniesshowallofthefea−
?1847Eschara tubuliferaReuss, 1847: 67, pl. 8: 19. tures seen in the specimens attributed by Zágoršek (2010b)
2010bPhoceana tubulifera (Reuss, 1847); Zágoršek 2010b: 155, pl.
to Reuss’s (1847) species Eschara tubulifera, including the
114: 1–5.
characteristicmedianconvexityinsidetheapertures.Reuss’s
Etymology:Alludingtothethreehollowapicesofthetriangularhetero−
(1847)typematerialdiffers,however,inhavingmuchlonger
zooecium that lies against the proximal wall of the deep peristomial
peristomes and ovicells appear to be lacking. Study of the
shaft.Thefrontalapexistheopeningoftheheterozooecium;thetwo
shieldinteriorinthetypematerialhasnotbeenpossibleow−
basolateralapicesconnectwithanareolarseptularporeeithersideofthe
primary orifice. ingtoitstypestatusandtheMoravianmaterialistoofragile
Type material: Holotype: PM2−T 1245 (Fig. 4A), sample BAS 4. becauseofitsstateofpreservation.Accordingly,theattribu−
Paratypes:PM2−T1246andT1247(Figs.4,5),twospecimens,samples tion toE. tubuliferaReuss, 1847 is uncertain.
BAS 4. The intra−peristomial heteromorphic zooid is a striking
Type locality: Başyayla section, Turkey. feature,andthequestionarisesastoitspossiblefunction.Its
Type horizon: Upper Tortonian, Miocene. locationsuggeststwopossibilities—anavicularium,aglandu−
larchamber,orboth.Thefrontallyvisibleapexofthehetero−
Referred material.—Eight specimens, five of which having
morph is a small intra−oral (not suboral) foramen. In this re−
ovicells (PM2−T 1134, PM2−T 1155 to PM2−T 1158).
gard it is reminiscent of the suboral (sometimes intra−oral)
Diagnosis.—As for the genus.
avicularia that are seen in smittinids. These typically have a
Description.—Colony erect, rigid, narrowly bilamellar with cross−bar, which has not been seen in our material of O.
up to 10 longitudinal autozooecial series, circular to oval in triforamina(the heteromorph appearsdamaged in ourspeci−
cross section. Frontal shield evenly pseudoporous; marginal mens).Insmittinids,however,regardlessofthepositionofthe
areolar pores of same diameter as pseudopores. Primary ori− apertureofthesuboralavicularium,itschamberisalsosuboral
fice at bottom of deep peristomial shaft; no sinus, the broad andrestsuponthefrontalshield.InSmittinaandSmittoideait
posteralittlewidethantheanterandonethirditslength,with is median in position and originates from an areolar septular
apairofcondylesmarkingtheboundarybetweenthem;proxi− poreoneitherside.InHemismittoideaitisslightlylargerand
malaperturalrimstraightorgentlyconvex.Secondaryorifice off−centreandoriginatesfromasinglemarginalpore.
circular,surroundedentirelybybroad,peristomialrimthatis Waters(1894)wasthefirsttodocumenttheoccurrenceof
not markedly projecting, in the inner proximal margin of suboralglandularstructuresinanumberofcheilostomespe−
which is the tiny opening of a heterozooecium; chamber of ciesand Lutaud (1964) expanded onhislist.Shenoted that
heterozooeciumtriangular,withitsapexattheperistomialrim Smittina landsborovii (Smittinidae) has probable glandular