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BULLETIN DE L' INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE, BIOLOGIE, 71: 5-35, 200I BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN, BIOLOGIE, 71: 5-35, 2001
Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living supraspecific taxa of Chondrichthyan fishes.
Editor: M. STEHMANN
Part C: Superorder Holo _~ephali 1: Order Chimaeriformes Suborder Chimaeroidei- Family Callorhynchidae- Subfamily Callorhynchinae- Genus: Callorhinchus, Family Chimaeridae - Genera : Chi1naera and Hydrolagus, Family Rhinochimaeridae Genera: Harriotta, Neoharriotta, and Rhinochi mae ra. by J. HERMAN, M. HOVESTADT-EULER & D.C. HOVESTADT.
Abstract Part C: Holocephali 1: Order: Chimaeriformes - Suborder: Chimaeroidei Part C of thi s seri es describes and illustqtes with SEM or macrophotos the morphology of the tooth plates, the spines of the first dorsal fin and frontal tenacula of extant holocephalan genera. A General introduction differential diagnosis and systematic conclusions are summarized in the results. Part C of this series comprises the Holocephali. Like the Key words: Holocephali - Chimaeriformes - Chimaeroidei - Selachii and Batomorphii, the taxa of this superorder also Callorhynchidae- Chimaeridae - Rhinochimaeridae- Odontology. possess a cartilaginous endoskeleton. However, holocephalan teeth are not regularly shed like Selachii and Batomorphii but form slowly and permanently growing, Resume fused, massive tooth plates in upper and lower jaws. The Holocephali are subdivided into the three orders Dans Ia parti e C de cette serie, Ia morphologie des plaques den Cochliodontifmmes, Menaspiformes and Chimaerifmmes taires, ainsi que celle de l'epine de Ia nageoire dorsale et de l'appa (STAHL 1999). The first two orders are only represented by reil frontal tenaculaire des six genres recents d'Holocephales sont extinct taxa. The order Chimaeriformes comprises the subor decrites et figurees (macrophotos ou cliches MEB). Diagnose dif ders Echinochimaeroidei, Squalorajoidei, Myriacanthoidei, fe rentielle et conclusions systematiques so nt presentees dans les Chimaeropsoidei and Chimaeroidei. The latter only are rep conclusions. resented by both extinct and extant taxa, the others only by Mots-des: Holocephali - Chimaeriformes - Chimaeroidei - extinct taxa. The Chimaeroidei comprise the families Callorhynchidae- Chimaeridae- Rhinochimaeridae- Odontologie. Rhinochimaeridae, Chimaeridae and Callorhynchidae. The latter are subdivided after STAHL ( 1999) into the sub families Callorhynchinae and Edaphodontinae. Kurzfassung Edaphodontinae comprise extinct taxa only and, like all other extinct taxa, are not included in this study. Teil C di eser Serie beschreibt und illustriert durch REM oder If available, the dorsal fin spines and the frontal tenacula (a macrophotos die Morphologie der Zahnplatten, die Stacheln der feature only) are described and illustrated as well. erste dorsaler Fl osse und Stirnklasper von holocephaler rezente The authors will not draw any nomenclatorially valid conclu Gattungen. Eine Differenti aldi agnose und systematische Schluss sions. folgerung fassen di e Ergebnisse zusammen. The full bibliographical reference for each species will be Schiisselwiirter: Holocephali - Chimaeriformes - Chimaeroidei - given in the descriptive secti on and not be repeated under Callorhynchidae- Chimaeridae- Rhinochimaeridae- Odontologie. literature references. I I
6 J. HERMAN, M . HOVESTADT-EULER & D.C. HOVESTADT
Terminology MES IAL SECTION This is the part of the lingual face forming the symphysial The fo ll owing tenninology is used in thi s iss ue for describing connection with the opposite vomerine or mandibular tooth the tooth plates: plate, respectivel y.
Vomerine tooth plate =Upper anterior tooth plate. DISTAL SECTION Palatal tooth plate =Upper posterior tooth plate. This is the part interiocking of the two vomerine and the Mandibular tooth plate= Lower tooth plate. palatal tooth plates, respectively. (See textfigure I below) Tritor rods =Thin inner columns of hypem1ine- rali zed tissue. Family: Callorhynchidae GARMAN, 1901 Tritor pads =Rounded or oval external tips of internal tritor rods on the occlusal Subfamily: Callorhynchinae STAHL, 1999 surface, longitudinally abraded tritor rods on the lingual surface, INTRODUCTION or hyperminerali zed tissue of the The Callorynchinae comprise seven genera, of which on ly central ridge of mandibular tooth Callorhinchus is represented by li ving species. plates.
Generally, the terminology used by PATTERSON (1992) is used. However, extant chimaeroids have additional features Genus: Callorhinchus LACEPEDE, 1798 that are added below: The di stal margin is introduced as a fourth margin, which is This genus is represented by four extinct species (STAHL, often lost due to abrasion; lingual and lab ial margins join in a 1999) and the three extant species (DIDIER, 1995) C. di stal angle in such cases. Symphys ial border is replaced by capensis, C. milii and the type species C. callorhynchus. Spe mesial margin. Pal atal tooth plates have no sy mphysial mar ci es of this genus possess an additional patch of dermal gin, and mesial margin app li es to all types of tooth plates. denticles opposite those of the frontal tenaculum, directly at Further, is 'mesial ' commonly used as the opposite of tached to the skull integument. These denticles are equal to 'distal'. those of the frontal tenaculum and are not additionall y de For the lingual face, two additi onal terms are introduced scribed but we ll illustrated on plates I , 3 and 5. This phenom here: enon seems to be unique for the extant Holocephali; in the legend of the pl ates the proposed appelation is tenacular complex. Lacking material of the type species, C. capens is and C. milii Vomerine tooth plate Palatal tooth plate are used for descriptions and illustrations. (occluso-lingual view) (occluso-lingual view)
Material Distal section Lingual ,.,--- The following 4 specimen of 2 species were examined:
Callorhinchus milii ANSP 177821 · Tooth plates, no data IRSNB R.3455 o 78 em t.l. IRSNB R.348jaws, no data
Callorhinchus capensis Col i. Pi erre Coupatez o sk ull , claspers and dorsal fin
Tritor pads Ca llorhinchus m.ilii BORY & SAINT VINCENT, 1823 (Plates l and 2)
Callorhinchus milii BORY & SAINT VINCENT 1823 - Di cti onnaire classique d' Hi stoire naturelle. Rey et Gravier. Pari s. vol.3 , 62, pl.S.
Central fold Chimaera monstrosa HETERODONTY Lingual The dentition is dignathic heterodont. Hav in g a sin gle spec i Text figure I -Description of th e odo nt ological, spine of th e first men avail ab le onl y, neither sex ual nor ontogeneti c dorsal fin and tenac ulum characters heterodonty could be exam ined. I I
Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 7
VOMERINE TOOTH PLATE FRONTAL TENACULUM DENTICLES The more or less lozenge-shaped plate is about three times as The frontal tenaculum bears approximately a hundred dermal high as broad. The labial surface is undulated and bent lin denticles on its bulbous distal part, which are set in fourteen gually from the labial margin towards the lingual margin. more or less regular longitudinal rows. The size of the The lingual surface possesses an additional mesial and distal denticles diminishes toward the tenaculum's sides. Each der section. The narrow mesial secti on is smooth and fl at for mal denticle consists of a fl at, semi/oval, radiated basal plate linking with the opposite vomerine pl ate. The uppermost part and a hook-like cusp in the center on top. The cusp lacks cut of the broader, concave main secti on is always abraded, pre ting edges and is smooth. The basal surface each denticle of senting a single internal 111esial tritor rod along the mesial the semi-oval shaped fl ange is funnel shaped with a central margin. The narrow, smooth distal secti on is sl.ightly con aperture. cave, forming an interlock with the palatal tooth plate. Family: Chimaeridae BONAPARTE, 1831 PALATAL TOOTH PLATE INTRODUCTION The plate is of more or less trapezoid shape. The distal mar gin is narrow and about one-thi rd the length of the mesial The Chimaeridae comprises three genera, with Chimaera one. The mesial margin is sli ghtly arched, both labial and lin represented by extinct as well as extant species, and gual margins are more or less straight, and the labial one has Hydrolagus represented by extant species only. a fl attened tip. The labial surface presents a large, deep de pression in which the jaw part fits. A relatively narrow Genus: Chimaera LINNAEUS, 1758 enameloid-like band is present along the upper mesial, labial and distal margins. This genus is represented by nine extinct species (STAHL, The li ngual surface is slightly undulated and presents a large, 1999) and the six extant species (DIDIER, 1995) C. cubana, broad and semi-circul ar tritor pad that is bifurcated toward C. owstoni, C. jordani, C. phantasma, C. pseudomonstrosa the labial margin. and the type species C. nwnstrosa.
MANDIBULAR TOOTH PLATE Material These more or less lozenge-shaped plates have a distal mar gin that is less than half as long as the mesial one. The mesial The fo ll owing 13 specimen of the type species were exam margin is straight and its surface is concave. Tbe distal mar ined: gin is also straight, but the labial one is arched. The lingual margin is slightly undulated. The labial surface presents a Chim.aera monstrosa large, deep depression in which the jaw part fits. A relatively Coll.Herman 9 55 em tl. narrow enameloid-like band is present along the upper me Coll.Herman 9 58 em tl. sial, labial and distal margins. The lingual surface presents a Coli .Herman 0 56 em tl. mesial secti on forming the connecti on with the opposite Coll .Herman 0 61 em tl. mandibular plate. The surface is largely undul ated due to the Coll.Hovestadt 0 SO em TL presence of a relatively broad central ri dge. The part at the Coll.Hovestadt 0 44 em TL labial margin, along the cutting edge of the lingual surface is Coll.Hovestadt 9 95 em TL lost due to abrasion, with only a large, semi-circular central Coll.Hovestadt 9 75 em TL tritor pad remaining. Coll .Hovestadt 9 45 qn TL Coll .Hovestadt 9 45 em TL Coll.Hovestadt 9 40 em TL Coli .Hovestadt 9 40 em TL Callorhinchus capensis DUMERIL, 1865 Coll .Hovestadt 9 10.5 em TL (Plates 3 to 5)
Callorhinchus capensis DUMERIL, 1865. Histoire naturelle Chimaera monstrosa LINNAEUS, 1758 des poissons ou Ichthyologie generale. Edwards, George, (Plates 6 to 8) Paris. Vol l , 695, pl. 13, fi gs 5, Sa. Chimaera monstrosa LINNAEUS, 1758. Sy tema Natura. The dorsal fin spine possesses a sharp mesial ridge, which is ed. X, tome I, 824 pp. Nantes & Pisces: 230 - 338. serrated more or less regularly over three-quarters of its length. The ti ps of the seiTation is upturned and become HETERODONTY shorter toward spine's ti p. The dentition is dignathic heterodont. Neither sexual nor on The distal face is a relatively shall ow, broad central grove. togeneti c heterodonty was found. The lateral margins bears minute tubercles, with their tips downturned, along spi ne 's the upper half. The lateral sur VOMERINE TOOTH PLATE faces are convex in cross-secti on. The interior of the spine is The more or less rectangular plate is about twice as high as holl ow. broad and a little twisted around its vertical axis. The labial ''
8 J. HERMAN, M. HOVESTADT-EULER & D.C. HOVESTADT
surface is bent from the labial margin towards the lingual The distal face is a relatively shallow central furrow. Its lat margin. Vertical striae, oriented almost parallel, are present, eral margins bear tubercles, with their tips downtumed, along formed by the tips of the internal tritor rods at this surface. the spine's upper half. The lateral surfaces are convex in The lingual surface is subdivided into mesial and distal sub cross-section. The interior part of the spine is hollow. sections. The nmTow mesial secti on is smooth and flat to link with the opposite vomerine plate. The relatively broad main FRONTAL TENACULUM DERMAL DENTfCLES section bears well-developed, horizontal ridges, of which the The frontal tenaculum bears approximately 70 dermal mesial and distal edges of which are bent labially, so that denticles on its bulbous distal part, arranged in a patch of ten each ridge is of trapezoid shape. The surface between these more or less regular longitudinal rows. The size of the ridges slopes from the top of each ridge to the base of the denticles diminishes toward tenaculum 's sides. Each denticle previous one. Along the labial the cutting edge of the main consists of a more or less flat, semi-oval, radiated basal plate section the surface is strongly abraded, leaving five to six with a hook-like cusp on top. The basal face of each dermal tritor rods visible that lay against the labial surface. The nar denticle is funnel shaped with a central aperture. row, smooth distal section is slightly concave and interlocks Most of the elongated, curved cusps have a central and two with the palatal tooth plate. lateral cutting edges and smooth surfaces.
PALATAL TOOTH PLATE The plate appears more or less trapezoid or triangular, de Gs nus: Hydrolagus GILL, 1862 pending on the presence or absence of a distal margin. This margin is often indistinct due to abbrasion, with a distal angle This genus comprises 17 extant species (DIDIER, 1995): H. remaining only. The mesial margin is arched, ~md the labial affinis, H. africanum, H. alberti, H. barbouri, H. colliei, H. and lingual margins are slightly sigmoid and joining in a deani, H. eidolon, H. lemures, H. macrophtalm.us, H. media, distal angle. The labial surface is bent lingually from the la H. mirabilis, H. novaezealandiae, H. ogilbyi, H. bial margin toward lingual margin. purpurescens, H. waiti, the type species H. mitsukuri and the The slightly undulated lingual surface bears up to six short lately decribed H. pallidus. Lacking material of the type spe tritor pads along the labial margin and up to five more larger cies the latter species was selected for description and illus elongated mesio-lingual ones. The latter are lined up almost tration. parallel from the mesial margin toward the distal angle. Tritor pads are absent closer to the distal angle. If the lingual Material surface is less abraded, the tritor rods are visibie through the thin enameloid-like surface layer, in which case elongated, 20 specimen of 5 species were examined: mesio-lingually directed tritor pads are absent. Hydro lag us affinl s Coli. Hovestadt 0 80+ em tl. MANDIBULAR TOOTH PLATE The distal margin of this more or less trapezoid plate is less Hydrolagus mirabilis than half the length of the mesial one. The mesial margin is Coli. Herman 0 68 em tl. arched, the distal and labial ones more or less straight. The Coli. Herman 0 75 em tl. mesial and labial margins join in a rounded angle. The lin Coli . Hem1an 0 74 em tl. gual margin is slightly undulated. The labial surface is Coli. Herman 0 72 em tl. slightly convex and bent mesio-distally, with the mesial part Coli. Hem1an 0 70 em tl. bent stronger than the distal one. Vertical striae, in almost Coli. Heiman 0 69 c;n tl. parallel arrangement, result from the tips of the internal tritor Coli. Heiman 0 68 em tl. rods that lay against this surface. The mesial section of the Coli. Hem1an 2 65 em tl. lingual surface presents is narrow, smooth and Oat, to form Coli. Heiman 2 68 em tl. the link with the opposite mandibular plate. The remaining Coli. Herman 2 70 em tl. surface is undulated due to the presence of a relatively broad Coli. Heiman 2 72cm tl. central ridge. Along the labial cutting edge the lingual sur Coli. Herman 2 75 em tl. face is strongly abraded, leaving six distal and a mesial tritor Coli. Hovestadt 2 74cm tl. rod visible, that lay against the labial surface, and the tritor Coli. Hovestadt Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 9 Hydrolagus pallidus HARDY & STEHMANN, 1990 The dorsal fin spine possesses three sharp, distinct, mesial (Plates 9 and 10) ridges, of which at spine's base the central one is approxi mately three times higher than the lateral ones. The distance Hydrolagus pallidus HARDY & STEHMANN, 1990. A new at spine's base between the central ridge and each lateral deep-water ghost shark, Hydrolagus pallidus ridge almost equals the height of the central rid ~e but nar n.sp.(Holocephali , Chimaeridae), from the Eastern North At rows as the spine tapers toward its apex. The height of the lantic, and redescription of Hydrolagus affinis (BRITO central ridge diminishes toward the apex, and the three ridges CAPELLO, 1867). Archiv fur Fisch Wissenschaft 40 (3): join to become one ridge close to the apex. Small tubercles 229-248. with upward pointed tips are found on the lower section of the central ridge. HETERODONTY The distal face is a relatively shallow central furrow. Its lat eral margins bear tubercles, with their tips downturned, along The dentition is dignathic heterodont. Neither sexual nor on the spine's upper half. The lateral surfaces are convex in togenetic heterodonty was fo und. cross-section. The interior part of the spine is hollow. VOMERINE TOOTH PLATE FRONTAL TENACULUM DERMAL DENTICLES The more or less rectangular plate is about twice as high as The frontal tena_fish commission steamer due to the presence of a relati vely broad central ridge. The 'Albatros'. No.30. On Ha riotta, a new type of chimaeroid labial margin along the cutting edge of the lingual surface is fish from the deeper waters of the northwestern Atlantic. Pro strongly abraded leaving six distal and one larger mesial ceedings of the United States National M useum 17 (1014): tritor rod visibl e that lay against the labial surface. 471-473. I' 10 J. HERMAN, M . HOYESTA DT-EULER & D.C. HOYESTADT HETERODONTY present at each side of the ridge up to half the spine's lenght. The dentitio n is di gnathi c heterodont. Neither sexual nor on The di stal face is slightl y concave or almost fl at, with a low togenetic heterodonty were found. central ridge at the lower half of the spine. Its lateral margins bear minute tubercl es, with their tips downturned, along the VOMERI NE TOOTH PLATE spine's upper two-third part. The lateral sm faces are convex The pl ate is mesiall y enl arged. The mesial edge of the labi al in cross-secti on. The interi or part of the spine is hollow. margin forms a very sharp angle (about 20°) with the mesial margin, fo rming a hook-shaped cutting edge with the arched FRONTAL TENACULUM DER MAL DENTICLES mesial margin . The labi al cutting edge abruptly bends hori Te frontal tenaculum is three as long as broad and bears ap zontall y a nd fin all y fo rms a rounded j uncti on with the di stal proximately dermal denticles on its bulbous distal part , margin , which is sli ghtl y arched. The lingual margin is arrranged in a patch of eight more or less regul ar longitudinal straight. rows. The size of the denticles dimini shes toward tenacu The pl ate is a little twisted around its verti cal ax is. The labi al lum's sides. Each denticle consists of a hook-li ke cusp on surface is bent fr om the labi al margin toward s the lingual top. The basal face of each dermal denticle is funnel shaped one. Vertical stri ae, ori ented almost parall el, are present with a central aperture. formed by five to six internal tritor rods that lay against this Cutting edges on the elongated arched cusp are present at surface. The lingual surface is subdi vided into mesial and each side an<;t,s urfacess are mooth. di stal subsecti ons. The narrow mesial secti on is smooth and fl at, fo rming the link with the opposite vomerine plate. The relati ve ly broad main secti on is convex and smooth . With the Genus: Neoharriotta BIGELOW & SCHROEDER, 1950 excepti on of the mesial part, a large part at the labi al side, along the cutting edge of the surface of the main secti on is This genus comprises the three extant species (DIDIER, strongly abraded, leaving up to ten tritor rods visible that lay 1995), N. carri and N. pumila and the type species N. against the labi al surface. The narrow, smooth di stal secti on pinnata. Lacking materi al of the type species, N. pumila is is sli ghtl y concave and interl ocks with the palatal tooth pl ate. used fo r descriptjon and illustrati on. Dorsal fin spine and frontal tenaculum were lacking for descripti on and illustra PALATAL TOOTH PLATE ti on. T hi s pl ate is more or less trapezoid . The mesial margin is M ATERI AL sli ghtl y arched, the lingual margin s li ghtl y ·sigmoid and the di stal one straight and about one-quarter the length of the The fo ll owin g I specimen of I species were examined: mesial margin. The labial surface is bent linguall y from the labi al margin towards lingual one. Neoharriotta pwnila The sli ghtl y undulated lingual surface bears up to seven di s ANSP 172538 (Paratype) o 2 1 em tl. , isolated tooth tin ct tritor pads along the labi al m argin . Several tritor pads plates onl y. are merged in the mesio-mid secti on several, fo rming a large convex surface. Neoharriotta pumila DIDIER & STEHMANN, 1996 MANDIBUL AR TOOTH PLATE (Pl ate 14) The more or less trapezoid pl ate has a distal margin that is about one-fift h of the length of the· mesial one. The mesial Neoharriotta pumila DIDIER & STEHMANN 1996. margin is sli ghtly arched, the distal and lingual ones are more Neoharriotta pwnila, a new species of Longnose Chimaera or less strajght. from the Northwestern Indian Ocean (Pi sces, Holocephali , The labi al margin is structured by a few rounded indentati ons Rhinochimaeri dae). Copeia 1996 (4): 955-965. between the tritor rods, probabl y caused by abrasions. The lingual margin is sli ghtly undul ated. The labi al surface is HETERODONTY sli ghtly convex and bent mesio-distall y, with the mesial part T he dentition is di gnathic heterodont. Sexual or ontogenetic stronger bent than the di stal one. Vertical stri ae in almost par heterodonty coul d not be examined with onl y a single speci all el arrangement result from the intern al tritor rods that lay men available. again st this surface. The mesial secti on of the lingual surface is narrow, smooth and fl at to fo rm the link with the opposite VOMERINE TOOTH PLATE mandi bul ar plate. T he remaining lingual surface is undul ated T he pl ate is more or less quadrangul ar. The pl ate is a little due to the presence of a relati vely broad central ridge, whi ch twisted around its verti cal ax is. T he labial surface is bent is supported by a large tri tor pad. The labial margin along the from the labi al margin toward the lingual margin . cuttin g edge of the lingual surface, is strongly abraded, leav Ve rti cal striae, oriented almost parall el, are present formed in g five distal and th ree larger mesial tritor rod vi sible that by the internal tritor rods that lay against this surface. The lay against the labial surface. lingual surface is subdivided in to mesial and distal subsec tions. T he narrow mesial sectio n is smooth and fl at, fa nning The dorsal fin spine possesses one sharp mesial ri dge that the lin k with the opposite vomeri ne plate. T he relati vely dimin ishes in height toward the apex. M inute knobs are broad main secti on is convex and smooth. A large part at the '' Contributions to the study of the comparati ve morphology of teeth and other relevant ichthyodorulites II labial side, along the cutting edge of the surface of the main Coli. Hovestadt 120 ern tl. section is strongly abraded, leaving nine tritor rods visible Coli. Hovestadt 150 ern tl. that lay against the labial surface and additionally five mesial Coli. Hovestadt 150 em tl. ones. The narrow, smooth distal section is slightly concave and interlocks with the palatal tooth pl ate. Rhinochimaera pacifica ANSP 1778 12 No data PALATAL TOOTH PLATE This plate is more or less trapezoid. Its mesial, lingual and distal margins are straight and the distal one is one third of Rhinochimaera atlantica HOLT & BYRNE, 1909 the length of the mesial margin only. The labi al margin is (Pl ates 15 to 19) straight with a flattened tip. The labial surface is bent from the labial margin towards lingual one. Rhinochimaera atlamica HOLT & BYRNE, 1909. Prelimi The slightly undulated lingual surface bears up to ten, small, nary note on some fishes from the Irish Atlantic slope. An distally located tritor rods, a large one merged wi th the tritor nals and Magazine of Natural History, series 8, 3: 279-280. pad of the central ridge and three smaller tritor pads that are mesially, all located along the labial margin. HETERODONTY The dentition is dignathic heterodont. Neither sexual nor on MANDIBULAR TOOTH PLATE togenetic heterodonty"\vas found. T he distal margin of this lozenge-shaped plate is about half the length of the mesial one. The mesial and distal margins VOMERINE TOOTH PLATE are straight, the lingual one is arched. The labial margin is This plate has an arched mesial margin. The mesial edge of structured by rounded indentati ons between the tritor rods, the labial margin makes a sharp angle (about 60°) with the probably caused by abrasions. The lingual margin is undu mesial margin. The labial cutting edge gradually slopes to lated, due to a well-developed central ridge. The labial sur wards the distal angle. T he lingual margin is straight. face is slightly convex and bent mesio-distall y, with the me The labial surface is bent from the labial margin towards the sial part stronger bent than the distal one. Vertical striae in lingual margin. Neither tritor rods nor tritor pads are present. almost parallel arrangement result from the internal tritor The lingual surface is subdivided into mesial and distal sub rods that lay against this surface. The mesial secti on of the sections. The narrow mesial section is smooth and flat, fo rm lingual surface is narrow, smooth and flat to fo rm the link ing the li nk wi th the opposite vomerine plate. The relatively with the opposite mandibular plate. The remaining lingual broad main section is convex and smooth. A large part at the surface is strongly undulated due to the presence of a rela labi al side, along the cutting edge of the surface of the main ti vely broad central ridge. The labial margin along the cutting section is strongly abraded, leaving nine tritor rods visible edge of the lingual surface is strongly abraded, leaving nine that lay against the labial surface and additionally five mesial small mesial, one large central and four smaller tritor rod vis ones. The narrow, smooth distal section is slightly concave ible that lay against the labial surface. The central tritor rod is and interlocks with the palatal tooth plate. merged the large tritor pad that supports the central ridge. PALATAL TOOTH PLATE The plate is triangular. T he mesial margin is slightly arched Genus: Rhinochimaera GARMAN 190 I and joins the lingual margin in a rounded angle. The slightly arched lingual margin j oins the labial one in a sharp angle of This genus comprises the three extant species (DIDIER, about 20_. The lingual and mesial mm·gins j oin in an angle of 1995) R. atlantica, R. africana and the type species R. about 30_. The labial surface is bent from the labial margin pacifica. Lacking sufficient material of the type species, R. towards lingual margin. The concave lingual surface is atlantica was used for descri ption and illustrati on. smooth and bent from the labial margin toward lingual mar gin. Tritor rods and tritor pads are absent. MATERIAL The fo llowing 14 specimen of 2 species were examined: MANDIBULAR TOOTH PLATE T he plate is triangul ar. The mesial margin is straight and Rhinochimaera atlantica joins the lingual margin in a rounded angle. The lingual mar Coli. Herman 12 J. HERMAN, M. HOYESTADT-EULER & D.C. HOVESTADT Its lateral margins bear minute tubercles, with their tips DORSAL FIN SPINES downturned, along the spine's lower half. The lateral sur- · Although such material of Neoharriotta was lacking, signifi faces are convex in cross-section . The interior part of the cant intergeneric differences were noted in the other genera. spine is hollow. Generall y, the dorsal fin spine has a central ridge at the me sial face and convex lateral faces. Callorhinchus, Harriotta FRONTAL TENACULUM DERMAL DENTICLES and Rhinochimaera share a mesial central ridge and convex The frontal tenaculum bears approximately 80 dermal lateral faces. They can be di stinguished by the distal spine denticles on its bulbous distal part, arranged in a patch of ten face. Callorhinchus possesses tubercles with downturned more or less regular longitudinal rows. The size of the tips at both lateral margins of spine's the upper third part , denticles diminishes toward tenac ulum 's sides. Each denticle Harriotta possesses tubercles with downturned tips at both consists of a more or less flat, semi-oval, radiated basal plate lateral margins of spine's the upper two-third part, and with a hook-like cusp on top. The basal face of each dermal Rhinochimaera possesses hardly perceptible tubercles at the denticle is funnel shaped with a central aperture. lateral margins of the lower spine part. The mesial spine face Cutting edges on elongated arched cusps are absent and sur of both Chimaera and Hydrolagus possesses three sharp, dis faces are smooth. tinct, mesial ridges, of which at spine's base the central one is approximately three times hi gher than the lateral ones. The distance at spine's base between the central ridge and each Differential diagnosis l.~.t era l ridge almost equals the height of the central ridge but narrows as the spine tapers toward its apex. The height of the TOOTH PLATES central ridge diminishes toward the apex, and the three ridges Although some extinct species have a different configura j oin to become one ridge close to the apex. The central ridge tion, the six extant chimaeroid genera all possess a pair of of Chimaera is smooth, whilst in Hydrolagus it has tubercles vomerine and palatal plates in the upper jaw and a pair of with upturned tips at spine's lower part. The upper distal mandibular plates in the lower jaw. spine face of both possesses tubercles with downturned tips The most significant morphologicall y distinctive features of on the lateral margins of the spine. the genera are summarized in table I . The tooth plate morphology of Rhinochimaera differs FRONTAL TENACULUM DERMAL DENTICLES strongly from the remaining five genera by the extraordinary The frontal tenacula of Callorhinchus, Rhinochimaera , shape of vomerine, palatal and mandibular tooth pl ates. The Harriotta, Chimaera and Hydrolagus are similar. They con palatal and mandibular pl ates have one sharp, more or less sist of a cartilaginous appendix at the skull 's fore head which straight labial margin, without any indentation between tritor bears an oval- to circular-shaped patch of dermal denticles at rods and tritor rods, and tritor pads are absent on vomerine, the tip. The denticles are more or less an·anged in semi-paral palatal and mandibular plates. lel rows. The numbers of rows, as well as the number of Callorhinchus is di stin gui shed from Chimaera, Hydrolagus, denticles within a row vary in each genus. Each denticle con Harriotta and Neoharriotta by a vomerine pl ate with a single sists of a more or less flat, semi-oval, radi ated basal plate mesial tritor rod onl y, a palatal pl ate with a sin gle bifurcated with a hook-like cusp on top. The basal face of each dermal tritor pad and a mandibular plate with a single semi-circul ar denticle is funnel shaped with a central aperture. The elon tritor pad. Further, the palatal and mandibular plates have a gated, curved cusps of the dermal denticles of Chimaera and unique deep depression on the labi al surface. some of Hydrolagus have a central and two lateral cutting There are no significantly morphological differences be edges and smooth surfaces. Those of Harriotta only possess tween Chimaera and Hydrolagus. However, both can be dis lateral cutting eoges. Examined specimens of male of tinguished from Harriotta and Neoharriotta by a vomerine Callorhinchus present an opposite additionnal patch of plate with a low number of tritor rods (five) and a lingual denticles fixed on the skull , fanning a tenacul ar complex. surface with well-developed horizontal ridges; further by a Material of Neoharriotta was not available, but illustrated palatal plate with six distal and five mesial tritor pads and a male specimens in the scienti fic literature are only in posses mandibular plate with six distal and a single mesial tritor rod. sion of a common frontal tenaculum. Both Harriotta and Neoharriotta lack horizontal ridges on the lingual surface of the vomerine plate. However, Harriotta has a vomerine plate with up to ten tritor rods with Conclusions the most mesial one forming a hook-like extension, whilst that of Neoharriotta has nine distal anci five mesial tritor rods Concerning the tooth plate morphology, Rhinochimaera dif and lacks a hook-li ke extension. Their palatal plates differ, in fers severely from all other chimaeroid taxa. Am ong the re that Harriotta has seven small plus a large mesio-mid tritor maining taxa, Callorhinchus shares some general characters pad, whereas Neoharriotta shows up to ten small di stal, a li ke having tritor rods and tritor pads but has unique charac central and three smaller mesial tritor rods. Further, teristic features separating it from the other taxa (see differ Harriotta and Neoharriotta can be di stinguished by their en ti al diagnosis). Harriotta share more characters with the mandibular plates, on whi ch Harriotta has five distal and remaining taxa th an Callorhinchus but has an unique shaped three larger tritor rods, whereas Neoharriotta has up to ten vomerine plate. Neoharriotta, Chimaera and Hydrolagus small distal, a large central and four smaller mesial tritor share many characteristic features, and the latter two cannot rods. be separeted by tooth plate morphology. I I Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 13 Species Vomerine plate Palatal plate Madibular plate Cal/orhinc!ms - A single mesial tritor rod - One large bifurcated - One large sem i- - Main lingual surface tritor pad circular tritor pad smooth - Deep depression at the - Deep depression at the labia l surface labial surface Chimaera -Five or six tritor rods - Six di stal and five - Six distal and one -Main lingual surface with larger mesial tritor pads larger mesial tritor rod :· well developed ho rizontal - Short or lacking distal - Lingual central ridge ridges margin supported by a large tritor pad Harriotta - Up to ten tritor rods with the - Seven distal and one - Five distal and three mesial one .w.ith a hook-like large mesio-mid tritor larger mesial tritor rod extension pad - Lingual central ridge - Main lingual su rface - Short distal margin supported by a large smooth tritor pad Hydrolagus - Five or six tritor rods - Six distal and five - Six distal and one - Main lingual surface with larger mesial tritor pads larger mesial tritor rod we ll developed horizontal - Short distal margin - Lingual central ridge ridges supported by a large tritor pad Neoharriotta -Nine labia l and five mesial - Up to ten small distal, - Up to ten sma ll distal, tritor rods one large central an d one large central and - Main lingual surface three smaller tritor rods four smaller tritor rods smooth - Lingual central ridge - Lingual central ridge supported by a large supported by a large tritor pad tritor pad - Labial surface smooth - Labia l surface smooth Rhinochimaera - Tritor rods absent - Tritor rods absent - Tritor rods absent - Main lingual surface -Main li ngual surface - Main lingual surface smooth smooth smooth - Central ridge absent -Central ridge absen t - Sharp, straight cutting - Sharp, strai ght cutting edge edge Table I Concerning the type of character differences, the fo ll owing al so whould li ke to thank Captain P. GUEGUEN for all owing hypothetical phylogenetic intenelationships can be given and helping us to collect specimens and S. MAILLIOT (Uni (see textfigure 2): Chimaera and Hydrolagus cannot be dis versity Claude Bernard, Lyon, France) for the gift of a tinguished and could be considered congeneric. Harriotta specimen. Rhinochimaera is clearl y different from all other taxa. The remaining taxa Harriotta, Chimaera!Hydrolagus and Neoharriotta may form a subgroup in which Harriotta Bibliography clearly distinguishes. DIDIER, D.A. 1995. Phylogenetic Systematics of Extant Dorsal fin spine morphology indicates a closer relationship Chimaeroid Fi shes (Holocephali , Chimaeroidei) . No vitates, Ameri of Harriotta , Rhinochimaera and Callorhinchus and a sepa can Museum of Natural HistOJ)', 3119: l-86. ration of these genera from Chimaera and Hydrolagus . PATTERSON, C. 1992. Interpretation of the tooth plates of Neoharriotta cannot be interpreted due to lacking material. chimae roid fi shes . Zoological l ou mal of th e Linnean Society, l 06 (I ): 33-61. Frontal clasper morphology presents too little character vari STAHL, B.J. 1999. Chondrichth yes III Holoceph ali . In : Hand book ati on for distingui shing extern ally between the genera. of Paleoichth yo logy Yol.4. Gustav Springer Verlag, Stuttgart: 164 pp. Acknowledgments Additional references The authors thank Dr. G. LENGLET and his assistant Mr. G. COU LON, Institut Royal des Sciences Naturelles de Belgique, BIGELOW, H.B. & SCHROEDER, W. C. 1953. Fi shes of the West Brussels for giving access to specimens at hi s di sposal, Dr. ern North Atl anti c, Memoir Sears Foundcaionfor marine research, DIDIER-S AG IT and Mr. M. SABAJ, Nati onal Academy of l. part 2: 515 -562. Natural Science, Philadelphia for the loan of specimens and DEAN, B. 1904. Notes on the long-snouted chimaeroid of Japan, Dr. M .-H . DUBU IT, Coll ege de France, Laboratoire de Rhinoc himaera (Harri otta) pac ifica. Journal of th e Co llege of Biologie M arine, Concarneau for provid ing specimens. We Science of the Imperial Unive rsity ofTokyo 19.4: 20 pp. Triter rods and tritor pads absent Rhinochimaera -!'> !- ;:r: tTl ::0 3::: )> _z Chimaeridae Vomerine· plate with a single mesial tritor rod 3::: Vomerine, palatal and Palatal and mandibular plate with one semi-cicular tritor pad and no tritor rods ;:r: 0 mandibular tooth plates til present Callorhinchus I (/) ):! ....,0 Vomerine plate with an extended rr, c hook-shaped mesial tritor rod r tTl Harriotta 1::0 Ro Palatal plate with a singel tritor pad 0 Triter rods or 0 tritor pads present ;:r: 0 < Vomerine, palatal and tTl (/) madibular plates with ):! Vomerine plate with several tritor rods Neoharriotta I~ more than 13 tritor rods Palatal and mandibular plate with several Vomerine plate with a non- tritor rods or tritor pads hook-shaped mesial tritor rod Palatal plate with Vomerine, palatal and several tritor pads madibular plates with Chimaera/Hydrolagus less than 13 triter rods Text figure 2 I\ Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 15 DEAN, B. 1906. Chimaeroid fi shes and their development. KARRER, C. 1972. Die Gattung Harriotta GOODE & BEAN, 1895 Washington D.C., Carnegie In stitution. 32: 156 pp. (Chondrichthyes, Chimaeriformes, Rhinochimaeridae). Mitteilun gen Zoologische Museum Berlin. 48.1 : 203- 221 . DIDIER, D.A. 1996. Neoharriotta pumila a new species of long. POLL, M. 1951 . Expedition oceanographique beige dans les eaux no se Chimaera from the Northwestern Indian Ocean (Pisces, cotieres africaines de I' Atlantique sud (1948-1949). Resultats Holocephali Rhinochimaeridae). Copeia 4: 955 - 965. scientifiques. IRSNB, Bru.xelles. vollV, fasc. I, 144-154. FOWLER, H. 1941. The fi shes of the group El asmobranchii , Holocephali, lsospondyli, and Ostarophysi, obtained by the United States Bureau of Fisheries steamer << Albatro ss>> in 1907 to 1910, chi efl y in the Philippine islands and adjacent seas. STEHMA NN , M. Institut fi.ir Seefischerei, Bundesforschungsanstalt fi.ir Fi scherei , Palmaille 9, United States Na tional Museum, Bulletin I 00, 13 , 486-510. D-22767 Hamburg, Germany. HARDY, S. & STEHMANN, M. 1990. A new deeper-water ghost (E-mail: I 06241.1657 @compuserve.com) shark Hydrolagus pallidus n.sp. (Holoceph ali , Chimaeridae) from the eastern North Atlantic and redescription of Hydrolagus affini s HERM AN, J. Service Geologique de Belgique. (Brito Capello, 1867). Archiv fur Fischerei Wissenschaft. 40, 3: 229 Rue Jenner 13 , B-1 000 Brussels , Belgium. - 248. INADA, T. & GOTO, M. 1979. Rhinochimaera pacifica, a long HOYESTADT-EULER, M. and HOYESTADT, D.C. snouted Chimaera (Rhinochimaeridae) in New Zealand waters. Merwedelaan 6, NL-4535ET Terneuze n, The Netherlands. Japanese Journal of !cthyology. 25. 4: 235 - 243. (E-mail: dmhoves [email protected]) '' 16 J. HERMAN, M . HOVESTADT-EULER & D.C. HOVESTADT Plate 1. Cal/orhinchus milii BORY & SA INT VINCENT, 1823. Male, 78 em t.l., off south east Australia, IRSNB, R. 3455, collected in 1874. Fig. I: parti al left lateral view of the head ; details of the frontal tenaculum complex: lateral view (fig.2) and dorsal view (fig.3). II Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 17 Plate 2. Ca /lorhinclws milii BORY & SA INT VI NCENT, 1823. Male, 78 em t.l., off south east Australi a, IRS NB R. 348 , co llected in 1874. Upper (fig. I) and lower (fi g. 2) jaws, with details of both lingual or functional face and labial with jaw attac hment surface growing of their res pecti ve vo merine (v), palatine (p) and mandibular (m) dental plates. Fig. 3 shows a pa n of the left side of the dorsal fin spine. I I 18 J. HERMAN, M. HOVESTAOT-EULER & D.C. HOVESTADT Plate 3. Ca llorhin chus capensis DUMERIL, 1865. Male, estimated total length circa 70 em, False Bay, South Africa. Co il. P. COUPATEZ. Left side view of th e skull (fi g. I), detail of th e tenawlu111 co111plex (rig.2) and first dorsal fin sp in e in co nn ec ti on with th e fin (fi g.3). II Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 19 Plate 4. Callorh inclws capensis DUME RIL, 1865. Male, estimated tota l length circa 70 em, False Bay, South Africa. Co il. P.CO UPATEZ. Tenaculum complex: «derm al denti cles (s pinu les) with in 1enaculun1 groove (fig. I), on th e tenaculum head (fig .2) and cl ose up of th e latter (fig.3). I I 20 J. HERMAN, M. HOYESTADT-EULER & D.C. HOVESTADT Plate 5. Ca /lorhinchus capensis DUMERIL, 1865. Male, estimated total length circa 70 em, False Bay, South Africa. Co li . P. COUPATEZ. Tooth plates, mandibul ars (m), palatals (p) and vomerines (v) ; the last one are in positi on on their carti lagineous support. II Contributions to the study of the comparati ve morphology of teeth and other relevant ichthyodorulites 2 1 Plate 6. Chimaera nw ns/rosa LI NNA EUS , 175 8. Left side view of th e jaws of a male circa 85 em t. l. (fig.l) and a female circa 95 em t. l. (fi g.2), both from Porcupin e Bank, Ireland, upper (fig.3) and lowe r (fig.4) jaw of a male circa 80 em t.l. Porcupine Bank, Ireland. first dorsal fi n spine and fin of the same male (fig.5) and detail of the frontal !enacu/unl of the same male (fig.6). 22 J. HERMAN, M. HOVESTADT-EULER & D.C. HOVESTADT Plate 7. Chimaera monstrosa LI NNAEUS , 1758. Female circa I 00 em t. l. , Wes t Flugga, North East Atl anti c, Upper (fig. I) and lower (fig.2) jaws, with details of both lingua l or functional, and labial plus att ac hment surface of th eir res pecti ve vo merin e (v) , palatine (p) and mandibul ar (m) dental plates. n 0 :J ::::. 0"'g_ 0 :J "' 8 s- (1) "'2 a. '< 0..., s- (1) (') 0 3 "0 !l> ~ < (1) 3 0..., "2.. £ 0 [/Q '< 0 ""T'> 0 (1) :T il> :Ja. 0 s- ...,(1) @ (b < !l> ;:?. (') ~ -< a.0 0 2 0 "' Plate 8. Chimaera monstrosa LI NNAEUS , 1758. Male circa 30 em t.l. , IV Southeast Rona, North East Atlantic. Right (fig. I) and front (fig.2) views of th e frontal tenaculum head. VJ I I 24 J. HERMAN, M . HOYESTADT-EULER & D.C. HOYESTADT Plate 9. Hydro /agus pallid us HARDY & STEHMANN, 1990. Male circa l 05 em t.l. , no precise locali ty data, < Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 25 Plate 10. Hydrolagus pa llid us HARDY & STEHMANN, 1990. Female circa 120 em t.l. , no precise locality data ,>>No rth Eas t At lanti c». Left lateral view of the jaws (fig. I ), inner view of upper (fi g. 2) and lower (fig. 3) jaws. Lingual and lab ial views of th e three left denta l pl ates (v, p, m). 0\N !- :c tn :>::l :s: )> z :s: :c 0 < tn (/) );! 0 -;" ctn r tn :>::l ?;,> 0 0 :c 0 < tn (/) );! -l0 Plate 11. Hydrufagus mirabilis (COLLETT , 1904). Male circa 75 em t.l. , no precise locality data, «North East Atlantic». Ri ght lateral (fig. I) and front (fig.2) views of the i'rontaltenacufum head. I I Contributions to the study of the comparati ve morphology of teeth and other relevant ichthyodorulites 27 Plate 12. Hariolla raleighana GOODE & BEAN , 1895 . Male circa 80 em t.I. , no precise locality data, «North Eas t Atl antic>> . Left lateral (fig. I) and facial views (fig.2) of part of th e sk ull. Lingual views of ri ght vo merin e (v) and palatin e (p) dental plates and lingual view of the left mandibul ar (m) dent al plate . Specimen ANS P 17781 1, «off New Zea land>>. '' 28 J. HERMAN, M . HOVESTADT-EULER & D.C. HOVESTADT Plate 13. Hariolla ra leighana GOODE & BEAN, 1895 . Female circa 90 em t.l. , no prec ise locality data, "North Eas t Atlantic". Inner view of upper (fi g.l ) and lower jaws (fi g.2) . Lingual (fun cti onal) and labi al views of th e three left dent al pl ates (v, p, m). I I Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 29 Plate 14. Neoha riolla piullila DIDIER & STEHMANN, 1996. Paratype , off Soco tra Island. ANSP 1725 38 ,Stat. 2565 , cr. 17 RIY Vi1ya z, 1000- 11 20 m depth. Lin gual or function al face of th e three dental plates, mac rophotos and SEM mag nification illustrations. '' 30 J. HERMAN, M . HOVESTA DT-EULER & D.C. HOVESTADT Plate 15. Rhinochi111aera calanrica HOLT & BYRNE, 1909. Female circa 130 em t.l. , South Lousy Bank, Nort h East Atl anti c. Left lateral view of th e skull (fig. I). Lingual or fun cti onal and labia l views of the three dental pl ates of a fe male spec imen circa 120 em t.l. (Bo ul ogne Fishh arbo ur). '' Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites 3 1 Plate 16. Rhinochimaera atlantica HOLT & BYRNE, 1909 . Mal e circa 110 em t.l. , no prec ise data of locality, << Nort h Eas t Atl anti c». Left latera l view of th e jaws (fi g. I). Male circa I05 em t.l. , Hatlon Bank. North East Atl anti c. Lingual or fun cti onal and labi al vi ews of the three demal pl ates (v, p, m ). VJ N :-- ::r: tTl :::::> ::::: )> .z ::::: ::r: 0 < (/)tTl ~ ....,0 I ctTl r tTl :::::> Ro 0 0 ::r: 0 < tTl (/) ~ ....,0 Plate 17. Rhinuchimaera atlantica HOLT & BYRNE, 1909. Male ci rca 105 em l.l., Hatton Bank North East Atlantic. Right lateral (fig. I) and front (fig. 2) views of the frontal tenaculum head. () 0 ;?. ..., & §.. 0:l "' 0 ;:::; <1> E"' 0. '< 0...,., So <1> () 0 3 -a ~ ?1 ::;::· <1> 3 0 -a ;:::; 9. 0 [IQ '< 0...,., n ~ ;:::; :l"' 0. 0 ...,~ (ii ~ < "';?. () g- :T '< 0 0. 0 2 n "' Plate 18. Rhinochimaera atlamica HOLT & BYRNE, 1909. Male circa I 05 em t.l. , Hatton Bank vJ North East Atlantic. Inner (fig. I) and outer (fig.2) views of the frontal tenaculum head after removing b.oth cartilage and fleshy attachment with single bacterial help. vJ w .:::.. :-- :r: tT1 ::0 s: )> z s: :r: 0 < tT1 (/) ~ 0 -;-I ctT1 r tT1 ::0 R.o 0 0 :r: 0 < tT1 (/) ~ 0-l Plate 19. Rhinochimaera allanlica HOLT & BYRNE, 1909. Male circa I 05 em t.l. , Hatton Bank North East Atlantic. Basal or radicular and lateral views of some of the tooth-like dermal denticles of the frontal lenaculwn head. I I Contributions to the study of the comparati ve morphology of teeth and other relevant ichthyodorulites 35 Plate 20. Lateral view of th e fro nt al tenaculum (fig. I), mag nifi ca ti on x3; left lateral and front views of th e tenaculum head (figs. 2a and 2b); lateral view of th e firs t dorsal fin spine (fi g.3) , magnifi cati on X2.