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BULLETIN DE L INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE BIOLOGIE 75 5 20 200i BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN BIOLOGIE 75 5 20 2005

Contributions to the odontological study of living Chondrichthyes. 2. The genus Oxynotus RAFINESQUE, 1810 by J HERMAN, M HOVESTADT-EULER & D C HOVESTADT

Abstract The tooth morphologv of three ot the four species ot the Material genus Ownotus is described and partly illustrated by SEM photo­ graphs An interspecific diagnosis re\eals the tooth morphological For this study , lollowing material was available Oxxnotus differences between the species O hitiiuensis O ccntuna and O hiuniensis Iwo males, Oxxnotus centnna 13 males and 16 paiadoxus Icmalcs, Oxxnotus paiadoxus 5 males and 3 females Kev words: Odontology - Chondrichth\es - Squalitormes - Oxvnotidae - Ownotus - Tooth morphologv Oxynotus RAFINESQUE, 1810 Resumé La morphologic dentairc de trois dcs quatre especes du genre Ownotus est detrite et liguree partiellement a 1 aide dc cli­ ches MEB Une diagnose interspecifique precise les dilterences The genus O \ A «of «5 comprises loui species O biuniensis morphologiques dcntaires obser\ees entre les especes O (OGILBY, 1893) , O canbbaeiis, CERVIGON 1961, the type biuniensis O centiina cl O paiadoxus species O centnna (LINNAEUS, 1758) and O paiadoxus FRADE 1929 Mots-cles: Odontologie - Chondrichthyes - Squahformes - Oxynotidac - Oxxnotus - Morphologic dentairc Oxynotus bruniensis (OGILBY, 1893) Kur^fassung: Die Zahnmoiphologie von dici von der vicr Arten OGILBY J D , 1893 Centi ma bi un tens is Records of the der Gattung Ownotus werden bcschricbcn und teilweise illustnert Austialian Museum Sidney 2(5) 62-63 mit REM Photos Eine interspezitische Diagnose zcigt die /ahn- Textplates 1,2, plates 1 to 3 moiphologische Unterschicdc zwischen den Arten O biuniensis O centiuia und O paiadoxus For the first schematic illustration ol upper and lower teeth Schlusselworter: Odontologie - Chondrichthyes - Squalitormes - see GARRICK JAF, 1960 Studies on New Zealand Oxynotidac - Oxxnotus - Zahnmorphologic Elasmobranchu XI Squaloids ol the genera Deania Ctmopteius, Oxxnotus and Dalatias in New Zealand waters Transaction of the royal Society of New, Zealand Wellington Introduction 88(3) 519-557 6 figs For a second one, with correct illustrations of outer faces of With the exception of O centiina the tooth morphology of one upper tooth and one lower tooth see LAST PR & the taxa of the genus OxMiotus is pooily known For this STEVENS J D 1994 Sharks and Raxs of Austialia CSIRO study tooth material was available of O hruniensis O division of Fisheries Sidney 513p,84pl (of p 105) centnna and O paradoxus Due to lacking tooth samples of O caiihbaeiis this species could not be incorporated in this This species shows a strong dignathic heterodonty and a study The tooth morphology of O biuniensis and O weak monognathic heterodonty The root is always paradoxus will be described and illustrated O centnna, anaulacorhizid which was described and illustrated by HERMAN, The dimensions of the lower teeth are subcentrimetrical, HovESTADT-EULER & HovESTADT (1989), will be used here those of the upper teeth plurimilimetrical in size and more information, as well as more illustrations are pro vided An interspecific differential diagnosis reveals their UPPER JAW tooth morphological differences For the terminology used here, see HERMAN, HOVESTADT-EULER and HOVESTADT The teeth arc compressed, having a more or less vertically 1989 elongated crown and root 6 J HERMAN M HOVESTADT-EULER & D C HOVESTADT

lextplate 1 • Oxynotus hrunieiisis (OGILBY, 1893). Male 560mm 11, caught off Wollongon Ncw-South Wales Australia Outer view of two upper left anterior teeth and the whole lower Icit toothset

lextpldte 2 . Oxywtus hriimensis (OGILBY, 1893). Male 'ifiOinm 11 cauaht oil Wollongon New South Wales Australia Diaaraph ol the same lower left loothstt Contributions to the odontological study of living Chondrichthyes / 2 7

The crown is twice as high as the crown base width and as UPPER JAW high as the root The symphyscal tooth has a symmetrical triangular crown The lateral teeth maintain symmetrical The teeth are compressed having a more or less vertically less high and narrower toward the commissure Both mesial elongated crown and root and distal cutting edges are smooth The height of the crown is twice as high as the ciown base The outer face is strongly convex and a broad apron extends width but half the lOOt height The symphyscal tooth has a nearly to the root base The apron is arched at the base and symmetrical triangular crown The lateral teeth show a slightly overhangs the root A true outer or inner ornamenta­ crown, becoming increasingly asymmetrical, less high and tion IS absent broader based toward the commissure Both mesial and distal cutting edges are smooth The root is elongated and has a moie or less rectangular ap­ pearance The basal edges of the loot are slightly rounded A The outer face is strongly convex and a bioad apron extends foramen is present at each side of the apron The inner face is nearly to the root base The apron is not o\erhanging the lOOt flat showing sometimes a median apeiture near the crown- but forms one part with it A true outei or inner ornamenta­ loot junction A shallow less developed medio-basal sulcus is tion IS absent present The root IS elongated and has a more or less rcctangulai ap­ pearance From the ciown root junction downwaid the root is narrowing and the basal edges aie slightly rounded Two or LOWER JAW three foramina aie piesent at each side of the apron The in I he teeth are strongly compressed and interlocked The ner face is flat showing a median aperture near the crown crown base width is appiox 30% less than its height, and loot lunction sometimes a poorly developed median \eitical also 30% the lOot height The crown is high and symmetri gioove is present which is moie distinct on the lateial and cally triangulai in the symphyscal teeth but becomes incieas- posterior teeth A deep medio-basal sulcus is always piesent ingly asymmetrical and less high in lateial and commissural teeth The crown possesses a lelatnely well developed LOWER JAW lounded blade at each basal edge, continued upward as a poorly developed seriation which disappears totally toward The teeth are strongly compressed and interlocked The the apex The mesial blade is absent at lateial teeth and those ciown base width is equal to its height but half the root toward the commissuie Both cutting edges are more or less height straight The crown is high and symmetrically tiiangular in the sym The outer face ol the crown is convex and a veiy broad apron physial teeth but becomes increasingly asymmetrical and extends nearly to the root base The apron is not overhanging less high in lateral and commissural teeth The crown pos­ the root but forms one part with it From the crown-ioot junc­ sesses a relatively small bluntly rounded blade at each basal tion downward the apron continues its width and moie oi edge, continued upward as strong serration which becomes less narrows to hall its size neai its lowest pait A shallow 1 educed in upper crown half and finally disappcais totally aperture is present at each side of the apion The basal edges toward the apex The mesial blade diminishes in size on tooth of the root are slightly rounded A weak outer mesial depres positions toward the commissuie Both cutting edges are sion IS also due to interlocking strongly sigmoid On the inner face ot the ciown there is a well developed The outer face ot the crown is convex and a bioad apion ex­ uvula without basal costules or depression A laige median tends nearly to the loot base The apion is not oveihanging aperture is piesent at each side of the uvula and one large the 1 oot but forms one part with it From the crown root junc median aperluic below the uvula Ashoit broad medio ba tion downward the apron is narrowing to half its size A large sal sulcus is present Two to four foramina surround the sul aperture is present at each side of the apron Near the junction cus, and several scattered foiamina are on the outer basal oi the apron and root some vertical protuberances are edge of the root A weak innei distal depression is due to in present The basal edges of the root are slightly rounded A terlocking oi the lower teeth weak outer mesial depression is also due to interlocking On the inner face of the crown there is a rectangular uvula at the symphyscal tooth that becomes more oblique and less developed in teeth toward the commissure The uvula Oxynotus centnna (LINNAEUS, 1758) presents a basal depression A large median aperture is LINNAEUS, 1758 Squalus centnna Systema Naturae present at each side of the uvula and one large, median aper­ Ed 10(1) 233 ture below the basal depression A short broad, medio-basal Plates 4 to 6 sulcus IS present Two to four foramina surround the sulcus, and several scattered foramina are on the outer basal edge of This species shows a strong dignathic heterodonty and a the root A weak inner distal depression is due to interlocking weak monognathic heterodonty The root is always of the lower teeth anaulacorhizid The dimensions of the lower teeth are subcentiimetncal, those of the upper teeth plurimilimctrical in size 8 J. HERMAN. M. HOVESTADT-EULER & D.C. HOVESTADT

Oxynotus paradoxus FRADE, 1929 width, but hall the root height. The symphyscal tooth has a Bok'tini de Sociedadc Forliigiic.sa de Ciencias nuturais. symmetrical triangular crown with slightly arched cutting Lisboa. 10(22): 26.1-267, fig. 1. edges The lateral teeth maintain symmetrical, less high, and Tcxtplatcs 3. 4 . plates 7 to 10. narrower toward the commissure. Both mesial and distal cut­ ting edges arc smooth. This species shows a strong dignathic hctcrodonty and a The outer face is strongly convex and a broad apron extends weak nionognathic hctcrodonty. The root is always nearly to the root base. The apron is arched at the base and anaulacorhi/.id. slightly overhangs the root. A true outer or inner ornamenta­ The dimensions of the lower teeth are subcentrimetrical, tion is absent. those of the upper teeth plurimilimetrical in size. The root is elongated and has a more or less rectangular ap­ pearance with a slight constriction half way its height. The UPPER JAW root is slightly narrowing at he base and the basal edges arc slightly rounded. Foramina are absent at each side of the The teeth are compressed, having a more or less vertically apron. The inner face is flat showing a median aperture near elongated crown and root. the crown-root junction, becoming less developed in lateral The height of the crown is twice as hich as the crown base teeth and disappears near the commissural positions. A deep medio-basal sulcus is always present.

LOWER JAW

The teeth arc strongly compressed and interlocked. The crown base width is equal to its height, but half the root height. The crown is high and symmetrically triangular in the symphyscal teeth but becomes increasingly asymmetrical and less high in lateral and commissural teeth. The crown possesses a relatively well developed rounded blade at each basal edge, continued upward as a poorly developed serra­ tion, which disappears totally toward the apex. The mesial blade is absent at lateral teeth and those toward the commis­ sure. Both cutting edges are slightly sigmoid. The outer face of the crown is convex and a broad apron ex­ Textplate 3 : Oxynotus paradoxus FRADE, 1929. Female tends nearly to the root base. The apron is not overhanging 920mm t.l., caught off north-west Ireland, 540m the root but forms one part with it. From the crown-root junc­ depth. Ireland. Outer view of the upper dentition. tion downward, the apron continues its width and more or Magnification x6. less narrows to half its size near its lowest part. A shallow

Textplate 4 : Oxynotus paradoxus FRADE, 1929. Female 920mm t 1., caught oil north-west Ireland, 540m depth, Ireland Diagraph ot whole lower Icit tooihsct and of the symphyscal tooth (inner side) Magnil'ication xl4. Contributions to the odontological study ot living Chondrichthyes / 2 aperture is present at each side of the apron The basal edges height of the crown is twice as high as the crown base width, of the root are slightly rounded A weak outer mesial depres­ but half the root height in O bruniensis, O centnna and O sion IS also due to interlocking paradoxus On the inner face of the crown there is a uvula presenting coarse basal costulcs A large median aperture is piesent at LOWER JAW each side of the u\ula and one large, median aperture below the uvula A short broad mcdio-basal sulcus is present Two The teeth of O centnna\ lower jaw possess strongly sig to four foramina surround the sulcus and several scattered moid cutting edges that are less sigmoid in O paradoxus and foramina are on the outer basal edge of the i oot A weak inner more or less straight in O bruniensis The distal blade is distal depression is due to inteilocking of the lower teeth small and poorly developed in O centnna, but well devel­ oped in O bruniensis and O paradoxus in opposite to the mesial and distal serration that is poorly developed in O Interspecific differential diagnosis biunieinis and O paradoxus but well de\elopcd in O centnna UPPER JAW The crown base width is equal to its height, and half the lOot height in O centnna and O paradoxus but 30% less wide The teeth of O centnna s uppei jaw become oblique toward than the crown height and root height in O bntniensis the commissure with the outer apron not overhanging the The apron is gradually narrowing downward to half its size in root Those of O pmadoxus and O biuinensis maintain O centnna, but continues its width downward in O straight and the outer apion o\ei hangs the root The cutting biuniensis and O paiadoxus The uvula possesses a basal edges of the crown of O pmadoxus are slightly arched depression in O biuniensis coarse basal costules in O which aie straight in O centnna and O biuniensis The paradoxus, and is smooth in O bruniensis

Character detail Oxynotuf bruniensis Oxynotus centnna Oxynotus paradoxus Species

Upper jav. teeth toward commissuie oblique No Yes No

Upper jaw teeth apron overhangs the root Yes No Yes

Upper jaw teeth cutting edges shape arched No No Yes

Upper jaw teeth crown height twice the crown base width but half the loot height Yes Yes Yes

Upper teeth apron gradually narrows downwards No Yes No

Lower jaw teeth cutting edges shape sigmoid No Yes Yes

Lower jaw teeth cutting edges shape straight Yes No No

Lower jaw teeth distal blade well developed Yes No Yes

Lower jaw teeth serration well developed No Yes No

Lower jaw teeth crown base width equals height and half the root height No Yes Yes

Lower jaw teeth crown base width 307^ less than height and "ÏOVr of loot height Yes No No

Lower jaw teeth apron gradually narrows downwards No Yes No

Lower jaw teeth uvula with basal depression No Yes No

Lower jaw teeth uvula with coarse basal costules No No Yes

Lower jaw teeth uvula smooth Yes No No

Table 1 10 J HERMAN M HOVESTADT-EULFR & D C HOVESTADT

Conclusions CERVIGON F 1961 Una nucva especic dc 0\\/ï()/;« de las costas de Venezuela Ncnedadcs Cientifica Contiihuctones ocasionales Although gcncially the ihicc species shaie many tooth moi- del Musco dc Histoiia Natuial La Salle Seiie zooloi;ica Caracas phological chaiacteis, some signilicant diflcienccs appeal in 27 1-10 4 1igs botii uppci and lowci jaw (sec table 1 above) CoMPAGNOLJV 1984 FAG species catalogue Vol 4 Sharks of the world An annotated and illustrated catalogue ol shark species known to date Part I Hcxanchiformes to Lamniformes FAAO O centuna shares uppci and lowci teeth dimensions and Fishenes Synopsis Roma (125) Vol 4 Part I 24 129 lowei teeth sigmoid shape ol the cutting edges with O paiadoxus but none ol the characters with O hntmensis FRADI F 1929 Une nouvelle espece ou une aberration O paiadoxHs shares an overhanging apron ol the upper teeth indniduellc de 1 Oxxnotus centuna (L ) Boletiin de Sociedade Poilu^uesa dc Cuncias natuiais Lisboa 10(22) 263-267 fig 1 and a well developed distal blade with O hinniLUSis O hiuntensn is unique by straight cutting edges and aciown GARRICK J A F 1960 Studies on New Zealand Elasmohranchii XI Squdloids of the genera Deania ttinoplcius Oxxnotiis and base width ^0% less than its height and 30% ol root height in üalalias in New Zealand waters Tiansaction oj the loxal Soc letx of the lower teeth Ncu Zealand Wellington 88(3) 519-557, 6lig O centiina is unique bv possessing lateral and commissuia! teeth becoming oblique with a giaduall) narrowing apion in HIRMANJ H0VESTAI5T-EUI ER M & HOVESTADT D 1989 Con­ tributions to the stud\ of the comparative morphology of teeth and the uppei teeth and an apion giadually narrowing down- other rclc\ant ichthyodorulitcs in li\mg supraspecific taxa of waids a u\ula with a basal depicssion and a well developed Chondrichtyan lishcs Part A Selachu N° 3 Order Squalilormes serration on the cutting edges in the lowei teeth Families Echinorhinidae Oxynotidae and Squalidae Bulletin de O paradoxus is unique by arch-shaped cutting edges in the I Institut icnal des Sciences natuielles de Belgique Bioloi^ie upper jaw teeth and a u\ula with coarse basal costules in the Bruxelles 59 101-157 lowei teeth HERMAN J Hovi STADT-EULER M & HOVLSTADT D , 2003 Con The thiec species share the crown height that equals loot but trihutions to the study of the comparative morphology of teeth and IS hall the root height in the uppei teeth other relc\ant ichthvdorulites in li\mg supraspecific taxa of Chondrichthyan fishes Part A Selachu Addendum to 1 Order Hcxanchiformes 2 Order Carcharhiniformes 3 Order Squall- Acknowledements formes Tooth \asculan/ation and phvlogenetic interpretation Bul­ letin de I Institut loxal des Sciences ncUuielle'i de Belgique Biologie Bruxelles 73 5 26 Authors like to thank Di G Lenglet Institut royal des Sciences Natuielles de Belgique and Dr M McGrouthei, LAST PR & STEVENS J D 1994 ShaiksandRaxsofAustialia Australian Museum Ichthyology Section for giving access CSIRO division of Fisheries Hobart 513p,84pl to specimens at their disposal The SEM photographs were LINNAEUS K, 1758 Sysiema Naturae Ed 10 1 233 taken by J Cillis (Institut royal dcs Sciences naturelles de OGILBYJD 1893 Description of a new shark from the Tasmanian Belgique) coast RLcoidsofiheAustialianMuMuin Sidney 2(5) 62-63

Bibliography

BlGlLOW H B & SCHROlDLR WC 1948 Fishes of the Western North Atlantic Part 1 Mtmoiis Seauh Foundation foi Manni Re seaich New Haven 576p HERMAN, J CADFNAT J &. BLACHL J 1981 Rcquins de Mediterrancc ct IRSNB, Service Geologiquedc Belgique Rue Jennci 13, d Atlantiquc (plus parliculierement de la Cote Occidentale d'Atrique) Editions de I Office de la Reclieiche Scientifiqiie ct B- 1000 Brussels Belgium Technique Outie Mei Collection Faunc Tit)puale Pans 22 141- E mail J heiman (j*skynet be 149 CASIER E , 1961 Transformation des systemes dc fixation et de HOVESTADT EULER M & HOVESTADT, D C vascularisation dentaires dans 1 evolution des selaciens du Sous- Merwedelaan 6 Ordrc des Squalilormes Meinoiies de I Institut loxal des Sciences NL - 4535ET Terncu/cn The Netherlands natuielles dc Ihli;u/iic Bruxelles 2^"^^ Serie 6') 61p E-mail dmho\cst@/eelandnet nl Contributions to the odontological study of living Chondnchthyes / 2 11

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Plate 3 : Oxynotus hruniensis (OGILBY, 1893). Male "^óOmm 11 , taught oil Wollongon New-South Wales, Australia Inner and outer views ol the thiee first lower teeth m 2 > z

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Pldte 4 : Oxynotus centrina (LiNNALUS, 1758). Female 460mm t I caughl Cap-dcs-Biches, ^Om depth Dakar, Senegal Diagraph ol the whole lower toothset (inner \iew) Magnitieation x 9 o 3

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Plate 5 : Oxynotus centriiia (hlNNWV^, IISH). Female 460mm 11 caught Cap des Biches 30m depth, Dakar Senegal Outei and inner views ol uppei paiasymphyseal lateral and commissural teeth Magnilication x SO m S > z

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Plate 6 : Oxynottis centnna (LlNNAEUS, 1758) Female 460mm t 1 caught Cap des-Biches 30m depth Dakar, Senegal Outer and iner views ol symphyseal, third and commissural lower teeth Magnification x20 Contributions to the odontological study of living Chondrichthyes / 2 17

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Plate 8 : Oxynotus paradoxus FRADE, 1929. Female 920nini 1.1.. eaiighl oft' nortli-wesl Ireland. 54()ni deplh. Ireland. Outer view of ilie whole lower toothset. n o CT- C

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Plate 9 : Oxynotm paradoxus FRADt, 1929. Female 92()mm t I , caught oil north-west Ireland, ')4()in depth, Ireland Outer view ol the lowei light teeth (without the symphyseal) o

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P\dte U) -.Oxyiiolus paradoxus FRADK, 1929. Female 920mni t I taught olf north-west Ireland 540111 depth Ireland Inner view ol the lower right teeth (without the s>niph>seal)