Ontogeny of Ancyrodelloides carlsi (Boersma) and comments on its generic attribution (Conodonta, Lower Devonian)

Original

article

Ontogeny

of

Ancyrodelloides

carlsi

(Boersma)

and

comments

on

its

generic

attribution

(Conodonta,

Lower

Devonian)

§

Maria

G.

Corriga

,

Carlo

Corradini

*

a

DipartimentodiScienzeChimicheeGeologiche,Universita` diCagliari,CittadellaUniversitaria(BloccoA),SS.554bivioperSestu09042Monserrato(CA),Italy

b

DipartimentodiMatematicaeGeoscienze,Universita` diTrieste,viaWeiss234128Trieste,Italy

1. Introduction

Ancyrodelloides carlsi (Boersma, 1973) is a characteristic Lochkovianconodontspecies.ItisthelinkbetweengeneraLanea Murphy et Valenzuela-Rı´os and Ancyrodelloides Bischoff et Sannemann(Corrigaetal.,2014b),andisanimportant biostrati-graphicmarkerwithintheLochkovian.Severalauthorsconsiderit as the first representative of Ancyrodelloides (e.g., Murphy and Valenzuela-Rı´os, 1999; Corriga et al., 2014b), whereas others (Slavı´k,2011,Slavı´kandHladil,inpress)attributedthespeciesto Lanea.Inthispaper,basedonarichfaunafromMoroccoanddata fromtheCarnicAlpsthatallowtodemonstratetheontogenyofthe species, we support the attribution of the species carlsi to genus Ancyrodelloides, and we largely confirm the apparatus reconstructionbySlavı´k(2011).

2. Material

ThisworkismainlybasedonasamplefromMoroccocollectedby Prof.O.H.Walliserinthe1990sandstoredinthe‘‘Walliserconodont collection’’ at the Geoscience Centre, Georg-August University, Go¨ttingen,Germany,underreferencecollectionnumberGZG1612. Thesampleislabelled‘‘Wa3715’’andwascollectedfromaloose blockneartheAtrous3section,ca.12kmsouthwestofMerzouga,

southeasternTafilalt(Fig.1).Formoreinformationonthelocality andstratigraphicdata,refertoCorrigaetal.(2014a,2014b).

ThesampleyieldedarichpopulationofAncyrodelloidescarlsi, Zieglerodina eladioi Valenzuela-Rı´os and Pseudooneotodus beck-manni(BischoffetSannemann),besiderareelementsofBelodella resima (Philip) and Icriodus angustoides cf. alcolae Carls. The ramiformelementscanbeeasilysubdividedintotwogroups:one is representedby smallandthin elementswitha characteristic denticulation attributed to Z. eladioi (Corriga and Corradini, 2019),and theotherbylargeandstrongelements belongingto Ancyrodelloidescarlsi.

In this study we integrate the material from Morocco with collectionsfromtheCarnicAlps,whereA.carlsiisrelativelycommon inrockscollectedintheupperpartoftheRauchkofelandNo¨bling formationsandinthelowerpartoftheLaValuteFm.Infact,thelower boundaryoftheLaValuteFm.lieswithintheA.carlsiZone(Corradini etal., 2016,2019;Scho¨nlaub etal.,2017b).Inourcollections the speciesoccursintheRioMalinfier(Corrigaetal.,2012,2017)andVal diPuartisEast(unpubl.)sections.Also,weobservedthepresenceof elementsofA.carlsiincollectionsfromvarioussectionsfromthearea storedattheAustrianGeologicalSurveyinVienna:OberbuchachIb (Scho¨nlaubandCorradini,2017),OberbuchachII(Scho¨nlaub,1985; Scho¨nlaubetal.,2017a),OberbuchachIV(unpubl.),RauchkofelBoden (Scho¨nlaubetal.,2017b),RauchkofelSouth(unpubl.),andSeekopf Sockel(Scho¨nlaub,1980).

The studied material is stored at the Geoscience Centre of Georg-August University Go¨ttingen (GZG), Museo Friulano di Storia Naturale (MFSNgp), Museo di Paleontologia ‘‘Domenico

Geobios57(2019)25–32

ARTICLE INFO

Articlehistory: Received11June2019 Accepted2October2019 Availableonline23November2019 Keywords: Taxonomy Phylogeny Conodonts Lochkovian ABSTRACT

TheontogenyoftheLochkovianconodontspeciesAncyrodelloidescarlsi(Boersma)isdemonstrated thankstoarichpopulationfromMorocco.Thestudiedsampleincludeselementsatvariousgrowth stagesfromjuveniletogerontic.Thedataareconfirmedbyseveralelementsincollectionsfromseveral localitiesintheCarnicAlps(ItalyandAustria).Theabsenceofterracesateverystageofgrowthandthe presenceofastrongdenticulatedlateralprocessconfirmsthegenericattributionofthespeciestogenus Ancyrodelloides.Commentsontheapparatusareprovided.Thegeographicaldistributionofthespecies, limitedtoEuropeandtheMediterraneanregion,challengesitsstratigraphicvalueforlongdistance correlations.

C _{2019ElsevierMassonSAS.Allrightsreserved.}

§

Correspondingeditor:CatherineGirard. * Correspondingauthor.

E-mailaddress:ccorradini@units.it(C.Corradini).

Available

online

at

ScienceDirect

www.sciencedirect.com

https://doi.org/10.1016/j.geobios.2019.10.002

Lovisato’’ of Cagliari University (MDLCA), and the Austrian GeologicalSurvey. Precise information and repositorynumbers ofillustratedelementsarereportedinthecaptionofthefigures. 3. Systematicpalaeontology

ClassConodontaPander,1856 OrderOzarodinidaDzik,1976

FamilySpathognathodontidaeHass,1959

GenusAncyrodelloidesBischoffetSannemann,1958

Typespecies:AncyrodelloidestrigonicaBischoffetSannemann, 1958.

Original diagnosis (Bischoff and Sannemann, 1958; in Ger-man):Compoundconodontsconsistingofadenticulatedfreeblade andanarrow-shapedplatformwithtwoanteriorlobes,onwhich occasionallyone further lobe can be developed,and a pointed posteriorlobe.Theoralsurfaceoftheplatformissmooth,except forthefixedbladeandthemediancarinaeonthelobes.Asmall basalcavityisontheaboralsurfaceinmaturespecimens.

Emendeddiagnosis(MurphyandMatti,1983):Apolygnathid genuswithawell-developed,shelf-likeplatform,withorwithout

lateralprocessesand witha basalcavitythatis morerestricted thantheplatformexceptinthemostprimitiveforms.

Emendeddiagnosis(thiswork):Anozarkodinidgenusinwhich theP1elementischaracterizedbywell-developeddenticulatedand expandedlateralprocessesandabasalcavitythatismorerestricted thantheplatformexceptinthemostprimitiveforms.Theapparatus includessixelements(P1,P2,M,S0,S1andS2).

Remarks: Murphy and Valenzuela-Rı´os (1999) erected the genus Lanea separating from Ancyrodelloides those species characterizedbythepresenceof‘‘terraced,normally unornament-edbasalplatformlobes’’.InthediagnosisofLanea(Murphyand Valenzuela-Rı´os,1999:p.326)isalsoreportedthatearlymembers ofthegenushave‘‘openbasalgrooves,unrestrictedbasalcavities’’, andlatermembersshow‘‘constrictedbasalcavities’’.Thespecies attributedtoAncyrodelloidesdifferfromthoseofLaneabyhaving strong, denticulated lateral lobes, without a terrace; the basal cavityisopeninearlyforms(A.carlsi),restrictedinspeciesinthe middlepartofthelineage(A.transitansandA.asymmetricus),and reducedtonarrowgroovesinlateforms(A.trigonicus,A.kutscheri, etc.)(Fig.2).

ThephylogenyofAncyrodelloidesandLaneawasdiscussedby Corrigaet al. (2014b). In thatpaper weleft open theorigin of Fig.1.MapofNorthernAfricaandSouthwesternEurope(A)showingthelocationoftheMoroccan(B),AustrianandItalian(C)sectionscitedinthiswork.

M.G.Corriga,C.Corradini/Geobios57(2019)25–32 26

A.asymmetricusasevolvingfromA.carlsiorfromA.transitans.Now we believe that the second hypothesis is correct, as already suggestedbyMurphyandCebecioglu(1987),becausetheshapeof the basal cavity in A. asymmetricus and A. transitans is similar (Fig.2).Furthermore,thesetwospeciespartlyoverlap stratigra-phically in the upper part of the distribution of A. transitans, whereasa shortinterval occursbetween thelast occurrenceof A.carlsiandthefirstappearanceofA.asymmetricus(Fig.2).Likely A.asymmetricusderivedfromA.transitansbythelossofonelateral process.

Ancyrodelloidescarlsi(Boersma,1973) Figs.3–5

1958. Spathognathodus steinhornensis Ziegler – Bischoff and Sannemann,p.106,pl.13,figs.3,7?,9.

1973.Spathognatoduscarlsisp.nov.–Boersma,p.289-290,pl.3, fig.1–6;pl.4,fig.1–9.

1980.OzarkodinamasaraScho¨nlaub– Scho¨nlaub(inChlupac etal.),p.159,pl.20,figs.15–20.

1991.Ancyrodelloidescarlsi (Boersma)– Klapper (in Ziegler), p.9–10,pl.Ancyrodelloides-1,fig.

1994.Ozarkodinacarlsi(Boersma)–Valenzuela-Rı´os,p.64–66, pl.1,fig.19;pl.3,figs.3?,9–10,14.

2011.Ancyrodelloidescarlsi(Boersma)–Corriga,p.94–95,pl.6, figs.7–9.

2011.Laneacarlsi(Boersma)–Slavı´k,p.321–325,figs.3–8. 2012.Ancyrodelloidescarlsi(Boersma)–CorradiniandCorriga, fig.6P.

(SeeAppendixAforacompletelistofsynonymy.)

Material:inthesamplefromMorocco:46P1,5P2,2M,2S0and 3S1.IncollectionsfromtheCarnicAlpsweobservedafewdozens ofelements,bothP1,P2andramiforms.

Stratigraphicdistribution:MiddleLochkovian,fromthebase of the eponymous Ad. carlsi Zone into the Ad. trigonicus Zone (Corrigaet al., 2014b). Thefirst appearanceof thespecies was proposedfordefiningthebaseofthemiddleLochkovian(Slavı´k, 2011;Corrigaetal.,2014a,b).

Geographic distribution: Ancyrodelloides carlsi is widely distributedincentralandsouthernEuropeandnorthAfrica,being documentedinGermany(BischoffandSannemann,1958),Spain (Valenzuela-Rı´os, 1994; Valenzuela-Rı´os et al., 2005, 2017; Valenzuela-Rı´os and Liao, 2017), the Carnic Alps (Jaeger and Scho¨nlaub,1980; Scho¨nlaub,1980,1985; Corriga,2011;Corriga etal.,2012,2017;CorradiniandCorriga,2012;Scho¨nlaubetal., 2017a,b),Bohemia(Spassov,1971;Chlupacetal.,1980;Slavı´k, 2011,2017;Slavı´ketal.,2012),Morocco(LazreqandOuanaimi, 1998;Jansenetal.,2007;Rytinaetal.,2013;thispaper),Hungary (Kovacs,1981; Kovacs and Veto¨-Akos,1983; Kozur,1984), and Albania(Scho¨nlaubandMeco,1986).InNorthAmerica,theonly elementsomehowrecallingA.carlsiwerefiguredbyMurphyand Matti, 1983 (1983:pl. 2, figs. 13, 15, 17)from Nevada,but its attribution to A. carlsi is doubtful. The claimed occurrence in Australia (Farrell,2003)is here disregarded.The species is not documentedinChinauptodate.

Originaldiagnosis(Boersma, 1973):Aspeciesof Spathogna-thoduswithbroadlyflaringlipsofthebasalcavity.Theinnerlipis roundedandunornamentedinupperview.Theouterlipisslender, Fig.2.PhylogeneticrelationshipsofthegeneraLaneaandAncyrodelloides(modifiedafterCorrigaetal.,2014b)withreproductionofthelowerandupperviewsofthe holotypesorsignificativeelements(L.telleri)ofselectedspeciestoshowtheanalogousevolutionfromwideopentorestrictedbasalcavitiesinbothgenera.Conodont zonationafterCorrigaetal.(2016)andScho¨nlaubetal.(2017).Figuredspecimens:A.asymmetricus(BischoffetSannemann,1958),holotype;A.carlsi(Boersma,1973), holotype;A.transitans(BischoffetSannemann,1958),holotype;A.trigonicusBischoffetSannemann,1958,holotype;L.omoalpha(MurphyetValenzuela-Rı´os,1999), holotype;L.eleanorae(LaneandOrmiston,1979),holotype;L.eoeleanorae(MurphyetValenzuela-Rı´os,1999),holotype;L.telleri(Schulze,1968),elementfiguredbyMurphy andValenzuela-Rı´os(1999:pl.2,fig.38),becausetheholotypeisajuvenileelementanditsaboralviewisnotavailable.

Fig.3.P1elementsofAncyrodelloidescarlsi(Boersma).AllspecimensfromsampleWa3715,Atrous3locality,Morocco.Theelementsshowdifferentontogeneticstagesfrom younger(A)toolder(N)specimens.A.UpperviewofP1elementGZG1612-477-3715-7.B.UpperviewofP1elementGZG1612-477-3715-8.C.UpperviewofP1element GZG1612-477-3715-9.D.Upper(D1)andlower(D2)viewsofP1elementGZG1612-477-3715-9.E.UpperviewofP1elementGZG1612-477-3715-10.F.UpperviewofP1 elementGZG1612-477-3715-11.G.UpperviewofP1elementGZG1612-477-3715-12.H.UpperviewofP1elementGZG1612-477-3715-13.I.Upper(I1)andlower(I2) viewsofP1elementGZG1612-477-3715-14.J.upper(J1)andlower(J2)viewsofP1elementGZG1612-477-3715-15.K.UpperviewofP1elementGZG1612-477-3715-16. L.UpperviewofP1elementGZG1612-477-3715-17.M.Lower(M1)andupper(M2)viewsofP1elementGZG1612-477-3715-18.N.UpperviewofP1elementGZG 1612-477-3715-19.Scalebar:500mm.

M.G.Corriga,C.Corradini/Geobios57(2019)25–32 28

ornamentedattheuppersidewith1–3thickdenticles,androughly perpendiculartotheblade.

Emendeddiagnosis (Slavı´k, 2011): A species of Lanea with weakly developed terraces on basal platform lobes. The basal cavity is shallow, strongly asymmetrical and unrestricted. The outerplatformlobeisconsiderablylargerthantheinneroneand itsuppersideisornamentedwith1to3nodesinterconnectedwith thecuspbyafaintridge.

Emendeddiagnosis(thiswork): AspeciesofAncyrodelloides whose P1 elementis characterized by a stronglyasymmetrical platform. The outer platform is represented by a strong lobe, bearing1to4nodes,sometimesinterconnectedwiththecuspbya faintridge.Theinnerplatformisstronglyreducedorabsent.The basalcavitywidelyopen(scaphate)belowtheplatform.

Description:Theapparatusiscomposedbysixelements(P1,P2, M,S0,S1andS2).

P1element(Figs.3,4(A–C),5)pastiniscaphatecharacterizedby astrong bladebearing severaldiscrete triangulardenticles.The distaldenticlesoftheposterior(dorsal)processarelargerthanthe others, forming a cockscomb structure. The anterior (ventral) process, shorter than the posterior one and slightly laterally curved,bearsuptofivediscretedenticles.Thecuspissmalland similartoadjacentdenticles.Astrong,expandedlateralprocess bears1to4subtriangulardenticles.Asmallridgemayconnectthe denticles of the lateral process to the cusp. A small lobe, not ornamented, is present in the inner (?caudal) side; in a few

specimensitisslightlyinflatedandmayrecallaweaklydeveloped terrace,whereasinothersitisasmallbulgedecreasinginheight fromthebladetotheexternalpartofthelobe.Abrimispresentin thelowerouterpartofthelateralouter(?rostral)processandof theinnerlobe.Thebasalcavityiswideopen,occupiestheaboral partoftheplatformandextendsasagroovebelowtheprocesses. P2 element (Fig. 4(D, E)) pectiniform angulate with two processeslaterallycompressedforminganangleofca.1608.The strong, high, subtriangular cusp is posteriorly reclined. The anterior(ventral)processisthickerandstrongerthantheposterior (dorsal), andbearsaboutnine triangulardiscretedenticles. The posteriorprocesstaperstowardsthedistalextremity andbears about eleven subtriangular denticles; in thedistal third of the process denticles are of different size, alternating larger and smallerones(Fig.4(D2)).Thebasalcavityisrelativelywidebelow thecuspandbecomesthinnerbelowtheprocesses.

Melement(Fig.4(F))dolabratecharacterizedbytheposterior (adaxial) processcurveddownwardbearingaboutnine discrete denticles,circular incrosssection.Thecusp ishighandslightly laterally compressed, having an ovoidal cross section. A single smalldenticlemaybepresentanterior(abaxial)ofthecusp.The basalcavityiswiderbeneaththecuspandcontinuesasagroove towardstheposteriorend.

S0element(Fig.4(G))alatewithtwolateralprocessesforming anangleofca.1208.Thecuspishighandstrong.Theprocessesbear discrete alternate denticles. The narrowbasal cavity enlargesa Fig.4.Ancyrodelloidescarlsi(Boersma).AllspecimensfromsampleWa3715,Atrous3locality,Morocco.A.Upper(A1)andlower-lateral(A2)viewsofP1elementGZG 1612-477-3715-20.B.Upper(B1),lower-lateral(B2)andlower(B3)viewsofP1elementGZG1612-477-3715-21.C.UpperviewofP1elementGZG1612-477-3715-22.D.Lateral viewofP2elementGZG1612-477-3715-23(D1),andenlargementofthedistalpartoftheanteriorprocesstoshowthealternatedenticulation(D2).E.LateralviewofP2 elementGZG1612-477-3715-24.F.LateralviewofMelementGZG1612-477-3715-25.G.LateralviewofS0elementGZG1612-477-3715-26.H.LateralviewofS1element GZG1612-477-3715-27.Scalebar:500mm.

little on the anterior (rostral)side of thecusp and extends as groovesbelowtheprocesses.

S1 element (Fig. 4(H)) digirate with anterior (rostral) and posterior (caudal)process laterally compressed, bearing robust denticlescircularincrosssection.Denticlesonthedistalpartofthe anteriorprocessarebiggerandstrongerthantheothers.Thecusp isstrongandcircularincrosssection.Thebasalcavityenlargesa littleontheinner(dorsal)sideofthecuspandextendsasgrooves belowtheprocesses.

S2elementbipennate.InourmaterialallS2elementsarelargely incomplete, so we cannot provide a detailed description. In general,theelementhastwolaterallycompressedprocesseswith analternatedenticulation.

Remarks: In our material from sample Wa3715 there are several P1 elements of various sizes, from small to very large, allowingustodemonstratetheontogenyofthespecies(Fig.5). Smallerelements arenearly straightwitha subtriangular basal cavity,slightlylargerintheexternalside,whereonesinglesmall denticleispresent(Fig.5(A)),sometimesconnectedtothemain bladebyasmallnarrowridge(Fig.5(B)).Duringthegrowththe externalsideoftheplatformenlarges((Fig.5(C)),formingatrue lateralprocessabovewhichaseconddenticleappears(Fig.5(D)). Theouterpartoftheplatformremainssmallandslightlyinflated. Then,thedistalpartoflateralprocesscontinuestoextend(Fig.5(E, F)),firstinthelowerpart(Fig.5(G)),theninitsupperparttohosta third denticle (Fig. 5(H)). The growth continues analogously (Fig. 5(I)) until the development of a fourth denticle in larger specimens(Fig.5(J)).

TheapparatusofA.carlsiwasreconstructedbySlavı´k(2011) basedonmaterialfromtheCzechRepublic.Inoursamplefrom Morocco most elements are the same or very similar to that proposal, even ifsomedifferences shouldbe remarked. Our P2 elementshaveageneralmorphologyclosetothatfiguredbySlavı´k (2011:fig.4b–c,only),butthedenticulationpatternisdifferent: material from Morocco has discrete subtriangular denticles, whereaselementsfromBohemiashowcloselyspaced,rounded, smallerdenticles.ElementsM,S0andS1aresimilar.Inourmaterial wehaveonlybrokenS2elements,butseveralfragmentsrecallthe S2elementfiguredbySlavı´k(2011:fig.7).Thedifferencesinthe denticulationoftheP2elementaredifficulttoexplain,becausein both our and in Slavı´k (2011) samples there are no other spathognathodidtowhichmaybeattributedthoseP2elements, andalltheotherelementsarethesame.

4. Discussion

The generic attribution of the species carlsi (Boersma) is debated:theP1elementwasdescribedbyBoersma(1973)asthe morphospecies Spathognathodus carlsi, and then moved to Ancyrodelloides by Klapper (in Ziegler, 1991). Many authors

supportedthisgenericattribution,whereasSlavı´k(2011)claimed thatthespeciesbelongstogenusLaneaMurphyand Valenzuela-Rı´os.AccordingtothediagnosisofLanea(Murphyand Valenzuela-Rı´os,1999:p.326),‘‘earlyPamembersofthegenusrobustwith medium-tolarge-sized,terraced,normallyunornamentedbasal platformlobesandopenbasalgrooves,unrestrictedbasalcavity’’. Aterraceisaflatarea,moreorlesshorizontal,occupyingmostof the platform lobes. According to Murphy and Valenzuela-Rı´os (1999),representativesofLaneadifferfromAncyrodelloidesinthe generallackofridgesortuberclesonthebasalplatformterrace: theonlyspeciesofLaneawithasingledenticleononeplatform lobeisL.omus(MurphyetMatti).Ancyrodelloideshasstronglateral processes,withoutterraces,whichbearstrongdenticles.Thebasal cavityinLaneaiswidelyopeninearlyformsandconstrictedinlate forms.InAncyrodelloidesthebasalcavityislargerinA.transitans, andveryrestrictedinalltheyoungerrepresentativesofthegenus. Slavı´k(2011)basedhisattributionofthespeciescarlsitoLaneaon theshape ofthebasalcavitythatiswideopenandclaimedthe presenceofweaklydevelopedterraces.InouropinionA.carlsidoes not have terraces,which presence is diagnostic for Lanea. The apparentweak terracesactuallyaretheelongationoftheouter lobebeforetheappearanceofanewdenticle.Infact,asdiscussed above,during thegrow thedistalpart oflateralprocess (lobe) expandfirstinthelowerpart,theninitsupperpart,wherethe denticle will be hosted. The elongated upper part, before the appearanceofthenewdenticle,mayrecallasmallterrace.Inafew specimenstheinnerlobehasamoreorlessslightlyinclinedupper surface,recallingasmallterrace,whereasinthemajorityofthe elementsthisfeatureisnotpresent,asthelobegentlydecreasein height towardsthe baseof the platform.Also, theholotype of A.carlsi(Boersma,1973:pl.6,figs.1–3)clearlydoesnothaveany terrace.

AncyrodelloidescarlsiisthelinkbetweenLaneaand Ancyrodel-loides (Corriga et al., 2014b), and has a few characteristics intermediatebetweenthetwogenera.Thebasalcavityiswidely open,butwebelievethatthisisnotthemostimportantdiagnostic featureforthegenericattribution.AsshowninFig.2,bothgenera haveasimilarevolutionofthebasalcavity,thatislargerinolder speciesandmorerestrictedinyounger.Accordingtothediagnoses of Ancyrodelloides and Lanea, the absence of terraces and the presenceofthestrongdenticulatedlateralprocessarethekeyto attributethespeciestogenusAncyrodelloides.

AncyrodelloidescarlsiiswidelydiffusedinCentralEuropeandin theMediterraneanregion,whereitisaveryusefulandwidelyused indexspecies.Basedonthis,afewauthors(Slavı´k,2011;Corradini andCorriga, 2012;Corrigaetal.,2014b)proposed thatthefirst appearanceofthis speciesmayindicatethebaseof themiddle Lochkovian.However,A.carlsiisveryrare,ifnotabsent,intherest of theworld: therefore,itsvalue forglobal chronostratigraphic correlationsshouldbereconsidered,andadifferentmarkerforthe baseofthemiddleLochkovianmaybeindicated.Thesuggestionto

Fig.5.OntogeneticseriesofAncyrodelloidescarlsifromyounger(left)toolder(right)specimens.DrawingsbasedonelementsfiguredinFig.3.Someelementshavebeen mirroredtoalwayshavethelateralprocessontherightside.Scalebar:500mm.

M.G.Corriga,C.Corradini/Geobios57(2019)25–32 30

usethefirstappearanceofA.transitansforthispurpose(Murphy and Valenzuela-Rı´os,2017)looks a good proposal becausethis speciesisrelativelyabundantandwidelydocumentedeverywhere intheworld.

5. Conclusion

ThemainresultsofthisstudyonAncyrodelloidescarlsicanbe summarizedasfollows:

 thegenericattributiontoAncyrodelloidesisconfirmedbasedon theontogeneticreconstructionoftheP1element;

 thereconstructionoftheapparatusbySlavı´k(2011)islargely confirmed, with some differences only in the denticulation patternoftheP2element;

 thepossibleuseofA.carlsiasmarkerforglobalcorrelationsin the middle Lochkovian is questioned, due to its limited geographicdistribution.

Acknowledgements

HelgaGroos-UffenordehelpedduringthestudyoftheWalliser conodont collection, giving support during our visits to the GeoscienceCentreoftheGeorg-August UniversityofGo¨ttingen. HolgerGebhardtandIreneZornaredeeplythankedforallowing thestudyofcollectionsstoredattheAustrianGeologicalSurvey. G.B.DeGiudiciandG.Crucianiassisted withSEMphotography. Twoanonymousreviewers,ClaudiaSpallettaandthe Associate-Editor Catherine Girard provided useful comments, which improved the manuscript. This research was partly supported bygrants FIR(resp. C. Corradini)and is a contributiontoIGCP ProjectNo.652‘‘ReadingtimeinPaleozoicsedimentaryRock’’.

AppendixA.CompletelistofsynonymyofAncyrodelloidescarlsi 1958. Spathognathodus steinhornensis Ziegler - Bischoff and Sannemann,p.106,pl.13,figs.3,7?,9.

1969.Spathognathoduscf.asymmetricusBischoffetSannemann -CarlsandGandl,p.197,pl.19,fig.1.

1971. Spathognathodus steinhornensis steinhornensis Ziegler -Spassov,pl.1,figs.11–12.

1973.Spathognatoduscarlsisp.nov.-Boersma,p.289-290,pl.3, fig.1-6;pl.4,figs.1–9.

1980.OzarkodinamasaraScho¨nlaub-Scho¨nlaub,pl.2,figs.10, 16-17;pl.3,figs.24-30;pl.7,fig.3.

1980.OzarkodinamasaraScho¨nlaub -Scho¨nlaub (inChlupac etal.),p.159,pl.20,figs.15–20.

1980.OzarkodinamasaraMurphyetal.-JaegerandScho¨nlaub, pl.5,figs.10,16–17.

1981.OzarkodinaasymmetricaBischoffetSannemann-Kovacs, pl.1,fig.4(only).

?1983.Ancyrodelloidesomussp.nov.–A.transitans-Murphy andMatti,pl.2:13,15,17(only).

1983.OzarkodinamasaraScho¨nlaub-KovacsandVeto¨-Akos,pl. 5,fig.1.

1984.Ancyrodelloidesasymmetricus(BischoffetSannemann) -Kozur,pl.6,fig.3(only).

1985.OzarkodinamasaraScho¨nlaub-Scho¨nlaub,pl.2,figs.10, 16-17.

1986.OzarkodinamasaraScho¨nlaub-Scho¨nlaubandMeco,pl. 2,fig.21.

1991. Ancyrodelloidescarlsi (Boersma) - Klapper (in Ziegler), p.9-10,pl.Ancyrodelloides-1.

1994.Ozarkodinacarlsi(Boersma)-Valenzuela-Rı´os,p.64-66, pl.1,fig.19;pl.3,figs.3?,9–10,14.

1998.Ancyrodelloidescarlsi(Boersma)-LazreqandOuanaimi, pl.1,fig.14–15.

2005.Ancyrodelloidescarlsi(Boersma)-Valenzuela-Rı´osetal., fig.1a–b.

2011.Ancyrodelloidescarlsi(Boersma)-Corriga,p.94-95,pl.6, figs.7–9.

2011.Ancyrodelloidescarlsi(Boersma)-Corradinietal.,fig.12o. 2011.Laneacarlsi(Boersma)-Slavı´k,p.321-325,figs.3–8. 2012.Ancyrodelloidescarlsi(Boersma)-CorradiniandCorriga, fig.6P.

2012.Laneacarlsi(Boersma)-Slavı´ketal.,fig.6.8.

2012.Ancyrodelloidescarlsi(Boersma)-Corrigaetal.,fig.5.7– 5.9.

2013.Ancyrodelloidescarlsi(Boersma)-Rytinaetal.,pl.1,figs. 1–2.

2017b.Ancyrodelloidescarlsi(Boersma)-Scho¨nlaubetal.,pl.3, fig.12.

2017. Ancyrodelloidescarlsi (Boersma) - Valenzuela-Rı´os and Liao,fig.4.1.

2017.Ancyrodelloidescarlsi(Boersma)-Valenzuela-Rı´osetal., fig.4.6.

2017.Laneacarlsi(Boersma)-Slavı´k,fig.6.8.

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