ORYCTOS,Vol. 1 :3-21, Octobre1998

PRIMITIVENEOSELACHIAN : A SURYEY.

Gilles CUNY Department of Earth Sciences,University of Bristol Wills Memorial Building, QueensRoad Bristol, BS8 lRJ, UK.

Abstract : A study of the ultrastructureof the enameloid of isolated teeth demonstratesthat the neoselachiansharks, characteized by a triple-layered enameloid, radiatedjust after the Carnian, at the same time as some "experimen- tal", poorly known sharks (Vallisia, Raineria, Pseudodalatias and Doratodus). Most of the neoselachian teeth sharea hybodont-like architecture of the crown and a well-developed lingual torus in the root. Theselatter can be traced back at least in the . The clade Eunemacanthus + Amelacanthus + Hopleacanthus + + may have appearedas far back as the .Isolated Palaeozoicteeth belonging to Mcmurdodus and Anachronistes may not belong to neoselachiansharks. Most likely, these isolated teeth repre- sent the result of a convergencephenomenon in morphology and vascularisation.

Key words: Neoselachii, early , Palaeozoic,Triassic, enameloid ultrastructure.

Unerevue des néosélaciens primitifs ( : ).

Résumé : L'étude de I'ultrastructure du pseudo-émailde dents isolées montre que les néosélaciens,dont les dents sont caractériséespar la possessiond'un pseudo-émailà trois couchessuperposées, ont connu une importante radia- tion juste après le Carnien, en même temps que des requins plus "expérimentaux" dont les relations de parentés demeurentun mystère comme Vallisia, Raineria, Pseudodalatias et Doratodus. La plupart de ces dents de néosé- laciens du Trias supérieur montrent une architecture de la couronne très proche de celle des dents d'hybodonteset une projection linguale très nette de leur racine. Cette lignée remonte au moins au Trias inférieur. L'ensemble Eunemacanthus+ Amelacanthus + Hopleacanthus + Acronemus + Neoselachii est monophylétique et I'apparition de ce clade remonte au moins au Carbonifère.Les dents isolées de Mcmurdodus et d'Anachronisfestrouvées dans le PaléozoÏque,malgré des similitudes d'apparences,pourraient ne pas appartenirà de vrais Neoselachii mais semblent plutôt être le résultat de phénomènesde convergencede la morphologie et du système de vascularisation de ces dents.

Mots clés : Neoselachii, évolution, Paléozoïque,Trias, ultrastructure de I'émail.

INTRODUCTION the structure of their enameloid (fig. 1), which is for- med of three distinct layers: an external shiny-layered Two years âgo, I made a preliminary survey of enameloid (SLE) composed of thin apatite crystals the evolution of French faunas across the randomly oriented, a central parallel-fibred ename- Triassic- bound ary (Cuny, I995c). loid (PFE) formed mainly by surfac e-parullel apatite Concerning the selachians,I statedthat "...a study of fibre bundles running in a basal-apical direction, and the enamel ultrastructure of their (Hybodontidae) an inner tangled fibred enameloid (TFE) where the teeth could reveal that some teeth from above-mentioned fibres become randomly oriented. various stages belong in fact to neoselachiaTls....It Recent studies of the enameloid of Upper Triassic thus appears that the diversity of the neoselachians teeth have shown a triple-layered enameloid to during the may have been underestimated". occur in teeth previously thought to be of hybodont Indeed, according to Reif (T973), isolated teeth of affinities. The abundance of neoselachian sharks neoselachiansharks cAn be rec ognized on the basis of during the Upper Triassic has therefore been under- ORYCTOS,VOL. 1, 1998 estimated and, for the first time in their history, they EARLY STAGES IN THE EVOLUTION appearedto be well representedin the faunas. On the OF THE NEOSELACHIAN SHARKS. other hand, the Palaeozoic record of the Neoselachii remains scarce and intriguing. The evo- The Palaeozoic and early Mesozoic fossil record lution of the , from their first possible appea- of neoselachian sharks consists mainly of isolated rance in the Early to their first noticeable teeth, dermal denticles and fin-spines. Therefore, the radiation in the Upper Triassic, remains poorly details of the early evolution of this group are poorly known. The phylogenetic position of most of the fos- known. The first neoselachianshark may be as old as sils, which consists of isolated teeth or fin-spines are the Early-Middle Devonian, and is represented by still unclear. The present paper is intended as a quick some isolated teeth from Western Queensland survey of what we know (and don't know!) about the (Australia) and attributed to Mcmurdodus whitei early evolution of the Neoselachii. This review will (Turner &. Young, 1987). Another species, emphasize the study of the enameloid of the teeth. Mcmurdodus featherensis, is also known by a single The following abbreviations are used in the text: tooth from the Middle-Late Devonian of Antarctica BRSMG: Geology Department, Bristol City (see Turner & Young, 1987). The teeth of this genus Museuffi, BGM: Bath Geology Museuffi, GPIT: are strikingly similar to those of the Hexanchidae, but Department of Geology and Palaeontology, the first record of this family does not occur until the University of Tûbingen, IRSNB: Institut Royal des Lower Jurassic (Capp etta, I98l). As the structure of Sciences Naturelles de Belgique, SMNS: Staaliches the enameloid of the teeth of Mcmurdodus has not Museum ftr Naturkunde in Stuttgàft, SNP: Saint- been studied, and taking into account the stratigra- Nicolas-de-Port. phical gap from the first Hexanchidae, it is very dif- ficult to state whether Mcmurdodus is indeed the oldest known neoselachian.The similarity may be the result of a convergence in tooth morphology \\\\\\\\\\ (Capp etta et al., 1993). \\\\\\\\\\trrll/rr:/Jrt \\\\\\\\\\,r/tirrJrJrlJr The next oldest occurencesof possible neosela- \\\\\\\\\\JrJîJrJtJtJrJPtt \\\\\\\\\\JrJrJrJrttJîJrrr chian teeth are from the British Lower Carboniferous \\\\\\\\\\,îJrJrJtJrJrtJr"r \\\\\\\\\\JrJrtJrJrJ|JFli with the genus Cooleyella (Duffin &, Ward, 1983). \\\\\\\\\\iitrr,frr,trrrrr \\\\\\\\\\lJrlJrJtlJ"rrJl This genus is also known in the North American and tlriltlrt,rrl \\\\\\\\\\ Brazllian Upper Carboniferous (Duffin et al., 1996; \\\\\\':':':scE,"'l' Gunnell, 1933) as well as in the North American \\\\\\\\\\ilJrfir?,rlrr \\\\\\\\\\,t?lrrllfifdr (Duffin &. Ward, 1983). Duffin and Ward \\\\\\\\\\irrirrf.rrri.t \\\\\\\\\\,riJ.,trrttrrl (1983) stated that "Anachronistes(=Cooleyella) is a \\\\\\\\\\JrriJrJrJrrrtt \\\\\\\\\\if,/'rriilrirt neoselachian shark because it possessesa conical rrirrrrlrlîit \\\1\\\\\\ \\\\\\\\\\ftNrr,/drtrJrt central cusp, well-developed lateral blades and a \\\\\\\\\\JtiJri4rJr,rrJrr, Jrl,tlrrJtJrJrf basal flange, â V-shaped \\\\\\\\\\ basal face of the root, and a i,iffJrJr,JfJrJr typical neoselachian root vascularization (hemiaula- Hybodont Neoselachian corhize)". However, these teeth lack an enameloid cover, which is quite a problematic feature. Recent phylogenetic hypotheses accept the Hybodontoidea Fig. 1: Diagrammatic section of the enameloid in hybodont as the sister-group of the Neoselachii (Maisey, 1984; and neoselachiansharks. SCE: single crystallite enameloid. Gaudin, I99I) and the structure of the enameloid in SLE: shiny layered enameloid. PFE: parallel fibred ename- some Upper Triassic Neoselachii may suggestthat it loid. TFE: tangled fibred enameloid. is derived from a more primitive single crystallite enameloid (SCE). There is therefore little support for Coupe schématique du pseudo-émail chez un hybodonte et chez un néosélacien.SCE: pseudo-émailà cristaux simples. Duffin and Ward's hypothesis concerning the presen- SLE: couchede pseudo-émailbrillante. PFE: pseudo-émailà ce of unenamelled teeth in primitive neoselachians.A fibres parallèles.TFE: pseudo-émailà fibres enchevêtrées. secondary loss of the enameloid cover is also CUNY - PRIMITIVE NEOSELACHIAN SHARKS

problematic as there is no other example of such a genus? Egerton, 1872. This tooth dis- loss acrossthe whole lineage, and it is difficult to jus- plays a SLE and a PFE, but as there is only one tify this in mechanical terms. known tooth, it was impossible to look further to Moreover, a conical central cusp flanked by late- check the presence of a TFE. The association of a raI blades seems to be present in non-neoselachian SLE and a PFE is unknown outside the neoselachian sharks (Pseudodalatias, Doratodus, see below), sharks (Reif, I97l) and there is no doubt that this while Duffin and Ward (1983) noted that a basal flan- tooth belongs to a true neoselachian. To a large ge is also presentin the hybodont Steinbachodus(see extent, the diagnosis of the , below). Finally, the hemiaulacorhize state is, as far as including the Palaeospinacidae,is based on the struc- I know, unknown outside the Neoselachii but, given ture of the root, with a peculiar vasculaization ter- the present state of knowledge, convergence cannot med pseudopolyaulacorhize (Capp etta, 1987, 1992; be ruled out. All in all, the arguments to consider Thies, 1993; Duffin & Ward, 1993), while the overall Cooleyella a true neoselachianare rather weak (Thies morphology of the crown appears quite primitive & Reif, 1985;Turner &Young, 1987),and the phylo- inside the Palaeospinacidae.As the root is not preser- genetic position of this genus remains unclear. ved in the Turkish specimen, it is difficult to assess Hopleacanthus richelsdorfensis is quite a well whether this tooth does indeed belong to known genus from the Permian of Germany Palaeospinax. Palaeospinax is moreover a nomen (Schaumberg, 1982). It displays a mixture of hybo- dubium (Duffin and Ward, 1993; Thies 1993), and if dontid, ctenacanthid and palaeospinacid features this tooth does belong to a palaeospinacid,it should (Schaumberg, 1982). Maisey (1984) consideredit as therefore be attributed to the genus Synechodus. the sister-taxon of Palaeospinax + modern elasmo- Quite similar teeth have also recently been reported branchs on the basis of three synapomorphies: noto- from the strata of Nevada (USA) as chordal sheath segment calcified anteriorly; fin- ?Palaeospinax sp. by Rieppel et al. (1996). The roots spines with a mantle of shiny enameloid and lacking of these teeth are poorly preserved and the vasculari- posterior tubercles; and dermal denticles with a zation system cannot be properly observed. It is simple pulp cavity and a single basal canal. Gaudin impossible, for the same reasons as those given (1991) questionedMaisey's first and third synapo- above, to assesswhether these teeth belong to a true morphies and pointed out that the structure of the palaeospinacid. Moreover, the Iateral cusplets appear pectoral fins is primitive (contra Maisey, 1984). to be well separated from the main cusp, which Schaumberg's reference to "Placoidschuppe des accorditrg to Cappetta (1992) and Duffin and Ward Hybodus-types" appears however quite unclear. The (1993), is a characteristic of rather drawing of the vertical section of one of them than of Synechodus(the latter including teeth former- (Schaumberg, 1982: fig . 2) was made according to a ly described as Palaeospinax teeth). The roots of single abraded scale (Schaumberg,pers. com.) and a these North American teeth are projected lingually new study of the dermal skeleton of this genus would and pe{pendicular to the crown, which may indicate be welcome. TWo teeth of this genus aîe known, but neoselachian affinities (see below). The exact rela- the ultrastructure of their enameloid was not studied. tionships between the Nevada teeth and the neosela- Until a reassessmentof the structure of the teeth and chians, âS well as for the Turkish tooth. cannot be dermal denticles is made, the exact affinities of assessedat the present time. Hopleacanthus will be difficult to elucidate. The Acronemus tuberculatus, from the Middle character "fin-spines with a mantle of shiny ename- Triassic of Monte San Giorgio (Switzerland), was loid and lacking posterior denticles" also appearsin first considered as a ctenacanth shark (Rieppel, the Carboniferous genera Amelacanthus and 1982). Maisey (1984) pointed out two charucters Eunemacanthus, known only from fin-spines indicating some affinities of this genus with the neo- (Maisey, 1982). , selachian sharks: fin-spines with an ornament of The earliest unequivocal neoselachian tooth is shiny enamelled lateral tubercles and anterior keel, known from the Lower Triassic rocks of Turkey and an absenceof posterior denticles on the concave (Thies, 1982) and was attributed to the posterior wall; and body dermal denticles of the non- ORYCTOS.VOL. 1. 1998 growing, placoid type with widely spacedlongitudi- Vallisia coppi Duffin, 1982; Synechodus rhaeticus nal striae. However, the dermal denticles were not (Duffin, 1982); and nicolensis described in detail by Rieppel ( 1982), and very simi- Duffin , 1993. lar dermal denticles seem to occur in Hopleacanthus. moniliftr is known solely from Moreover, the teeth display only a single crystallite isolated fin spines, but is a common species in the enameloid (SCE), which would exclude this genus Upper Triassic of Western Europe. It has been repor- from the Neoselachii. A secondary adaptation to a ted in Great Britain (, Storrs crushing diet would however explain the loss of the 1994), France (Saint-Nicolas-de-Port, Cuny 8. triple layered enameloid in a neoselachian,as is seen Ramboer, 1991 ; Varangéville, Godefroit, 1997; in the Rajiformes and in the posterior teeth of Boisset, Cuny, 1993 a ; and Provenchères-sur-Meuse, Heterodontus. However, there is usually a remnant of Cuny, 1995b), Belgium (Habay-la-Vieille, Duffin et the tangled fibred enameloid, while, according to al., 1983), Luxembourg (Medernach,Delsate, 1995), Rieppel (1982), this is not the case in AcronemLts. Italy (Lombardy, Boni, 1937) and Germany Acronemus does not appearto be a true neoselachian, (Wurttemberg, Boni, I93l; Schmidt, 1928). The affi- but Acronemlrs, Hopleacanthus, Amelacanthus and nities of this genus were, for a long time, unclear. Eunemacanthus, may represent a paraphyletic sister- Maisey (1975) statedthat "Nemacanîhusis a slightly group of the Neoselachii, âs suggestedby Maisey earlier euselachiform shark than Palaeospinax, or else (1984). This would imply that the character: "fin- a ctenacanthiform closely allied to primitive spines with an ornament of shiny enamelled lateral Euselachiforrnes(i.e. Neoselachii)" and later (Maisey, tubercles and anterior keel and without any posterior I9l7) consideredit as "closely allied to Palaeospinax denticles on the concave posterior wall" is a primiti- and may represent an immediate ancestor". Cupp etta ve character for the Neoselachii. (1987) included it in the family Palaeospinacidae. The genus Nemacanthus is based solely on fin- However, as quoted above, the characters used by spines of a similar structure than those of Acronemus Cappetta to include it in the family Palaeospinacidae and were reported in the Lower Triassic of seem to be primitive for the Neoselachii. Cuny and Spitzbergen (Nemacanthus Sp., Stensiô, I92I), East Ramboer (1991) and Cuny (I995b) consideredit as a Greenland (I{emacanthus Sp., Stensiô, 1932) and derived ctenacanthoid.This assertion was based on Idaho, U.S.A . (Ir{emacanthus(Cosmacanthus) ele- the concave posterior wall of the spine, the central gans, Evans, 1904) and is common in the Upper cavity displaced backwards and the presenceof a row Triassic of Western Europe (I{emacanthus monilrfrr of hook-like denticles on the posterolateral margins. seebelow). The affinities of this genus are discussed This condition is very similar to that of Ctenacanthus later. The neoselachian fossil record from the (Maisey, 1981; Rieppel, 1982) and leads me to accept Devonian up to the Middle Triassic remains sparse, a ctenacanth ancestry for the neoselachian sharks, as with a low diversity and most of the having suggestedby Maisey (I975,1977). In contrast,recent uncertain phylogenetic positions. It is not even cer- analyses of the phylogeny of the chondrichthyans tain that the remains belong to true neoselachians.We (Gaudin, l99l ; Maisey, 1984) indicate that the sister- have to wait until the Upper Triassic to see more group of the Neoselachii is the Hybodontoidea. That diversified neoselachianfaunas. means that the similarities between the spines of Ctenacanthus and Nemacanthus afe based on primitive charactersonly, without any phylogene- A SURVEY OF THE POSSIBLE NEOSELACHIAN tic significance (Maisey, 1984). The presence of an SHARKS FROM THE UPPER TRIASSIC. enamelled ornamentation would preclude Nemacanthus from belonging to the Ctenacanthoidea Until recently, the neoselachian sharks were (Maisey, 1982), but would remain a primitive charac- known by six species in the uppermost Triassic ter for the Neoselachii. Whether Nemacanthus is a (Norian + ""), all restricted to Europe : true neoselachianor belongs to its sister-group (see Nemacanthusmoniliftr Agas siz, 1837; Hueneichthys above) appears impossible to prove on the basis of costatus Reif, 1977; Reifia minuta Duffin , 1980; fin-spines alone. CUNY - PRIMITIVE NEOSELACHIAN SHARKS

Hueneichthys costatus is known from a single side. This arrangement is quite reminiscent of the tooth (GPIT 1510) found in the German Rhaetic near Casier's (1941) squatinoid type, but a central fora- Stuttgart (Reif, 1977). The root of the tooth is not men on the basal face is lacking. It is therefore diffi- preserved and the crown is tricuspid and lacks any cult to assesswhether the relationships of Reifia are specific characters. According to the external shape with the Squalea or the Galea. only, this tooth could hardly be rec ognized as a shark Vallisia coppi is known from sevenisolated teeth tooth (Huene, 1933). It was the ultrastructure of the (BRSMG Cc 400 to 404, BGM CD 59,,60)found in enamel which allowed Reif (1977) to rec ognize that the Westbury Beds (, Somerset) and in this fossil belongs to a neoselachianshark. The tooth fissure fillings (Holwell, Somerset) (Duffin, 1982b). shows a SLE and a PFE. No TFE was found by Reif, This specieswas also found in Belgium near the vil- but as the tooth was unique, no section was made. It lage of Hachy, close to Habay-la-Viei11e,but no des- is therefore possible that a TFE exists below the PFE. cription has been published (Duffin et al., 1983). The According to Reif, the most important characteristic crown morphology of this genus is unique among of this tooth is the presence of an additional layer of neoselachians, and the superficial resemblances to fibres in the PFE at the level of the ridges ornamen- Orectolobiformes and Heterodontiformes seem to be ting the crown. The fibres of this extra layer run in a the result of convergence (Duffin, I982b; Capp etta, horizontal direction parallel to the surface. This fea- 1987). Duffin (1982b, 1983) suggestedbatoid affini- ture is unknown in any other neoselachian sharks. ty for this genus, based mainly on the holaulacorhize Reifia minuta is known from five isolated, minu- root morphology of the teeth. However, Duffin te teeth (SMNS 50.200to 50.204) found in the Lower ( 1982b) stated that some teeth have a rhinobatoid- Norian of Germany (Duffin, 1980). The enameloid is type vascularization, while others have a scyliorhi- imperfectly known, but seems to display at least a noid-type pattern. According to Casier ( 1947) howe- PFE and a TFE, although an SLE could also have ver, these two types of vascularization arose indepen- been present (Duffin, 1980). The TFE appearsquite dently. The scyliorhinoid-type is restricted to Galea peculiar, being made of single, randomly oriented while the rhinobatoid-type is only found among crystallites, rather than true fibers (Duffin, 1980 : fig. Rajifoffnes. Recent cladistic analysis of the extant 3e,3f). This structure is very reminiscent of that des- elasmobranchs(Shirai, 1996; De Carvalho, 1996) put cribed by Duffin (I993b) in Rhomphaiodon nicolen- the Rajifonnes into the Squalea, and support Casier's sis (see below). Based on the overall morphology of hypothesis that the two types of vascularization arose the teeth, Duffin ( 1980) suggestedthat Reifia was a independently. The appearanceof both types of vas- member of Galea (,sensuShirai, 1996) closer to the cularisation in Vallisia may suggest a rather different Orectolobiformes than to the Carchariniformes. evolution of the vasculaization system than that seen Cappetta (1987) pointed out, however, that the teeth in modern elasmobranchs.The presence of partially of Reifia lack the lingual enameloid protuberance at roofed grooves in some teeth, unknown in modern the base of the crown and the labial apron, which are holaulacorhize teeth, would also suggest the same. characteristicof the Orectolobiformes. He favoured a This may indicate that Vallisia sharcsno affinity with closer relationships with the Carchariniformes rather the modern elasmobranchs, neither Squalea nor than with the Orectolobiformes. However, the same Galea. As the structure of the enameloid has not yet author also pointed out the resemblance of the teeth been studied, it is difficult to prove that Vallisia is a of Reffia to those of some Batomorphii like real neoselachian. Sclerorhynchidae, which could indicate squalean Synechodus rhaeticus was first named as affinities rather than galean.The main problem is that Palaeospinax rhaeticus by Duffin in I982a on the the teeth of Reifia lack apomorphic characters at the basis of several fin-spines from the V/estbury Beds of level of the crown and the vascularization of the root Aust Cliff (South Gloucestershire, England) and in appears quite primitive. It is anaulacorhize, but with the fissure fillings at Holwell (Somerset, England). a reduction in the number of foramina on the lingual The presence of fin-spines and teeth of Palaeospinax side of the root. There is just one centro-lingual fora- was however noticed as early as 1889 by Woodward, men flanked by a margino-lingual foramen on each although the teeth mentioned by this latter author do ORYCTOS,VOL. 1, 1998

Fig. 2: A-E: Teeth of cf. Synechodusrhaeticus from the A-E: dentsde cf. Synechodusrhaeticus provenantdu rhétienen Rhaeticin A,C,E: apical and B,D: lingual views.A: Posterior vtresA,C,E: apicaleset B,D: linguales.A: Dent postérieureet and D,E: lateral teeth from Habay-la-Vieille (Belgium). B,C: D,E: Iatéraleprovenant d'Habay-1a-Vieille (Belgique). B,C: Dent Lateral tooth from Lons-le-Saunier(Jura, France). F-G: Teeth lat&ale provenantde Lons-le-Saunier(Jura, France). F-G: Dents of Pseudodalatiasbarnstonensis from the Rhaetic of Saint- de Pseudodalatiasbarnstonensis provenant du rhétien de Saint- Germain-les-Arlay (Jura, France). F: Upper tooth in Iateral Germain-les-Arlay(Jura, France). F: Dent supérieureen vue laté- view and G: lower tooth in labial view. H,I : Teeth of the new rale et G: dent inférieureen vtre labiale.H,I : Dents de la nouvel- speciesfrom Grozon in labial views. H: Anterior tooth and I: le espècede Grozonen vueslabiales. H: Dent antérieureet I: dent lateral tooth. All scalebars represent1 mm. latérale.Toutes les barresd'échelles représentent 1 mm. CUNY - PRIMITIVE NEOSELACHIAN SHARKS not seem to belong to Palaeospinax, but to a hybo- other Neoselachii (De Carvalho, 1996), or as basal dontifoffn shark (Duffin, I982a).In 1993 Duffin and Galea (Maisey, 1985, Cappetta, 1987), or as the sis- Ward claimed that the name Palaeospinax has to be ter-group of the Squalea (Duffin & Ward, 1993). The restricted to a single specimen of Palaeospinax pris- latter hypothesis is based only on dental characters, cus with no character of taxonomic value and is thus however. Such different interpretations highlight our a nomen dubium (for a review of the Palaeospinax lack of knowledge concerning primitive Neoselachii. problem, see Cappetta, 1987, 1992 and Thies , 1991, Rhomphaiodon nicolensis is known from hun- 1992, 1993). They move the species rhaeticus into dreds of teeth found in the French locality of Saint- the genus Synechodus.Teeth of "Palaeospinax rhae- Nicolas-de-Port, which is better known for having ticr,ts"have been cited in the "Rhaetian" of Habay-la- yielded numerous teeth of early mammals. These Vieille (Belgium) by Delsate and Lepage (1991). teeth are housed in the collection of the Institut Royal These authors provide rather poor illustrations and no des Sciences Naturelles de Belgique (SNP 1000 to real description of these teeth. They seem to be cha- 1005, SNP 1008 and hundreds of uncataloguedteeth) racterizedby rather low cusps. The accessorycusps (Duffin, I993b). Rhomphaiodon may also be present are not well separated from each other or from the in the Knollenmergel of Halberstadt (Germ&ny, main one. The crown is densely ornamented with Duffin, I993b) and this genus has been cited at ascendingridges. At the base of the labial face of the Varangéville, a locality a few kilometres east of crown, the ornamentation appears to be reticulate. Saint-Nicolas-de-Port, by Godefroit ( 1997). This lat- The root shows a pseudopolyaulacorhize vasculariza- ter author has provided no description nor illustration tion. I have also found rather similar teeth (fig. 28, C) of the teeth however. Morphologically, the teeth of in the "Rhaetian" of Lons-le-Saunier (Jura, France). Rhomphaiodon nicolensis ate quite similar to those Preliminary study of the enameloid of some teeth of "Hybodus" mino4 a conlmon speciesin the Upper from Habay-la-Vieille (fig. 2A, D, E) and Lons-le- Triassic of Western Europe. Teeth of "Hybodus" Saunier has revealed a thick layer of SCE (fig. 3A). minor are generally more squat and less elongate in Below, there is a layer of TFE, made of entangled overall shape than those of Rhomphaiodon nicolen- bundles of fibres of apatite crystallites (fig. 3B). This sis, with better developed ridges on the lingual side of structure appears very similar to that described by the crown. Teeth from juvenrle Rhomphaiodon nico- Reif (1973) in Heterodontus although the thickness lensis also show higher lateral cusplets than in juve- of the TFE is much more reduced in the Triassic teeth nile "Hybodus" minor (Duffin, 1993b). According to than in this latter genus. This structure could indicate Duffin (1993b), the enameloid of the teeth of a specialization toward a crushing dentition, as the Rhomphaiodon possessa unique triple-layered struc- SCE is resistant to compressive stresseswhile the ture with a surface SLE, a central PFE and a basal PFE is resistant to tensile stresses(Preuschoft et al., layer of haphazard single crystallite enameloid. This I97 4). This is in accordance with the low profile of latter layer appears strikingly similar to the basal the studied teeth. However, no formal description of layer of the teeth of Reifia minuta (comp are Duffin, the teeth of Synechodus rhaeticus is currently avai- 1980, fig. 3e, 3f and Duffin, I993b, PL.4,fig. 2). I lable in the literature (this should be done shortly, C. have studied the enameloid of one tooth from Saint- Duffin, pers. comm.) and the interpretation of these Nicolas-de-Port, and I have found the remnants of a results remains therefore problematic. The cyclos- surface SLE, a central PFE (fig. 3C) and a typical pondylous vertebrae reported in the Penarth Group in TFE made of entangled bundles of fibres of apatite Great Britain are often associated with Synechodus (fig. 3D). This latter layer was only found in the rhaetict,ts, since calcified vertebrae are unknown in upper third of the cusps. On the other hand, I was ctenacanthiform and hybodontiform sharks unable to demonstrate the existence of a basal layer (Woodward, 1889; Maise], 1977; Duffin, I982a; of haphazard single crystallite enameloid like that Storrs, 1994). The phylogenetic position of the illustrated by Duffin (I993b). These results may indi- Palaeospinacidae (Synechodus (Palaeospinax) + cate that at least two different speciesof neoselachian Paraorthacodus) remains much disputed. This fami- sharks co-existed in Saint-Nicolas-de-Port but more ly is sometimes considered as the sister-group of the work is required to reach a firm conclusion. ORYCTOS,VOL. 1, 1998

Fig. 3 CUNY - PRIMITIVE NEOSELACHIAN SHARKS

Fig. 3 : A-B: cf . Synechodusrhaeticus from the Rhaetic.A: Thick SCE-like layer at the surface of a tooth from Habay-la-Vieille (Belgium),etched 30s in I}Vo HCl. B: Inner TFE in a tooth from Lons-le-Saunier(Jura, France),etched 10mn 35s in 10VoHCl" C-D: "Hybodus'nminor (?) from Saint-Nicolas-de- Port (Meurthe-et-Moselle,France). C: PFE in a tooth etched50s in 70ToHCI and D: TFE at the apexof a tooth etched5mn 50s in 107c,HCl. E-Ii: New Grozon species.E: Appearanceof the TFE at the level of the ricigeof a tooth etchedZmn 50s in 10ToHCI andF: TFE at the apexof a tooth etched5mn 20s in 1A7oHCl. G-H: "Pseudocetorhinus picldordi" from the Rhaetic of Habay-la- Vieille. G: PFE in a tooth etched40s in 107o HCI andF{: TFE at the apexof a tooth etched 6mn 40s in IATa HCl. All the photographs represent the surf'ace of the teeth after etching"

A-B: cf. ,Svnechodusrhaetictts provenant du rhétien.A: Epais niveauressemblant à un SCE à la surface d'une dent provenant d'Habay-la-Vieilie(Belgique), attaquée 30s dansde I'HCI dilué à 104o.B: TFE interne dansune dent provenantde Lons-le-Saunier (Jura.France). attaquée 10mn 35s dansde I'HCi dilué à \07c. C-D: "Hybodus"minor (?) provenant de Saint-Nicolas-de-Port (Meurthe-et-Moselle.France). C: PFE dans une dent attaquée50s dansde I'HCI diiué à lAVcet D: TFE à 1'apexd'une dent attaquée 5mn 50s dansde I'HCI dilué à l}Tc. E-F: nouvelleespèce de Grozon.E: Apparitiondu TFE au niveau d'une ride d'ornementation surune dentattaquée Zmn 50sdans de I'HCX dilué à 107cet F: TFE à I'apexd'une dent attaquée5mn 20sdans de I'HC1dilué à l}Vc. G-H: "Pseudocetorhinuspickfordi" prove- nant du Rhaeticd'Habay-ia-Vieille. G: PFE dans une dent attaquée40s dans de I'HCI dilué à l07o et H: TFE à I'apexd'une dent attaquée6mn 40s dansde I'HCI dilué à I}Vc. Toutes les photographiesont été prises en surfaceaprès attaque à I'acide.

Fig. 4: A-D: Tooth of "Hybodus"minor from the Rhaeticof Aust (South Gloucestershire,England) in A: lateral, B: apical, C: labial and D: lingual view. E-H: Teeth of "Pseudocetorhinuspiclcfordi" from the Rhaetic in E,F: labial, G: lateral and H: lingual views. E,G,H from Habay-la-Vieille (Belgium) and F from Saint-Germain-les-Arlay(Jura, France). All scalebars represent1 mm.

Fig. 4: A-D: Dent d"'Hybodus" minor provenantdu rhétien d'Aust (South Gloucestershire,Angleterre) en vues A: latérale,B: api- cale, C: labiale et D: linguale. E-H: Dents de "Pseudocetorhinuspiclcfordi" provenantdu rhétien en vttes E,F: labiales,G: latérale et H: linguale. E,G,H provient d'HabayJa-Vieille (Belgique) et F de Saint-Germain-les-Arlay(Jura, France). Toutes les barres d'échellereprésentent 1 mm.

1l ORYCTOS,VOL. 1, 1998

Three other species from the Upper Triassic of species, reported in the Rhaetic of Great Britain Northwestern Europe have problematic affinities and (Westb.rry Formation, in at least nine localities: should be discussed here : Doratodus cf . tricuspida- Barnstone, Aust, Axminster, Blue Anchor Point, tus Schmid, 1861; Pseudodalatias barnstonensis Westbur], Penarth, , Lincolnshire, (Sykes, 197l); and Raineria osswaldi Cappetta, Leicestershireand Holwell:Sykes, 1974; Storrs, 1987. 1994), Belgium (Habay-1a-Vieille : Duffin et al., Doratodus tricuspidatus w4s originally descri- 1983;Attert, et a1.,1993),and the French Jura (Lons- bed by Schmid (1861) from the Lower out- le-Saunier : Cuny, I995à,c ; Saint-Germain-1es- cropping near Jena (Germany) but the type series of Arlay : Cuny et al., 1994; Boisset : Cuny, 1993a). teeth seem to have been lost (Duffin, 1981). Similar Pseudodalatias barnstonensis was also reported from teeth have also been reported in the Muschelkalk of the Norian of Lombardy (Italy : Tintori, 1980), but, Lorraine (France) by Sauvage (1883) and from the strangely, only lower teeth in connection were found, Lower Norian of Southwestern Gefinany (Doratodus and no upper teeth. Moreover, the tooth described by cf. tricuspidatus, Seilacher, 1943). The enameloid of Henry ( 1876) as Hemipristis lavigniensis in the theseteeth is formed by a SCE which suggestshybo- Rhaetic of Lavigny (Jura, France) may also represent dont affinities for this genus (Duffin, 1981). Duffin a lower tooth of Pseudodalatias (Cuny, I993b, but (1981) and Cappetta (1981) noted, however, that the seeDuffin, 1981). I have studied the ultrastructure of morphology of these teeth is very different from that the enameloid of some teeth from Aust, Habay-la- of any other hybodonts. The tooth crown is strongly Vieille and Lombardy. The enameloid layer (fig. 6A) differentiated from the root, and a crown/root junc- is indeed very thin, but so far, I am unable to confirm, tion deeply incised around the whole tooth is remi- or deny, Reifs observations. The affinities of this niscent of the neoselachiancondition (Duffin, 1981). genus remain, however, poorly understood (Duffin, The root morphology is unknown. While the structu- 1981; Cappetta,1987; Storrs, 1994;Cuny,I995c). As re of the enameloid precludes Doratodus from being is the casefor Doratodus, the teeth of Pseudodalatias a Neoselachii, it does not seem to be a hybodont show, in their overall shape, many similarities with shark either. those of neoselachians,but the structure of the teeth Pseudodalatias barnstonensis was first named as appears very different, which strongly suggests Dalatias barnstonensisby Sykes (1971) on the basis convergence. The relationship of Doratodus and of isolated teeth. The dentition of this genus, with a Pseudodalatias with hybodonts is poorly supported strong dignathic heterodonty, shows remarkable and the hypothesis that they belong to a different, convergence with that of the extant Dalatias new and ephemeral group cannot be dismissed. From (Squalea: Dalatiiformes: Dalatiidae) (fig. 2F, G). the Carnian to the end of the Rhaetian, marine faunas Later, however, Reif ( I97 8a) showed that these teeth were strongly modified (Benton, I99l), with the belong to a new genus which he named appearanceof the Teleostei and the explosive radia- Pseudodalatias and for which he erected a new fami- tion of the (Dapediidae, Semionotidae, ly: Pseudodalatiidae. This new family is characteri- Macrosemiidae, Pycnodontiformes ,, Caturidae) zed by teeth having a thin layer of a peculiar SCE, (Gardiner, 1993; Patterson, 1993; Tintori, 1996)" In with crystals perpendicular to the tooth surface in the Europe, the Rhaetian transgressionrepresented a way inner part of the enameloid layer but parallel to the for the Tethyan marine faunas to invade western surface, with a basal-apical direction in the outer part. Europe. The shallow sea covering the area was a Underneath the enameloid there is a thin layer of good environment for the radiation of new lineages. orthodentine. The rest of the crown and the whole This could explain the appearance at that time of root are formed by trabecular, acellular bone, a some ephemeralsidebranch shark lineages(Vallisia?, unique condition among advanced elasmobranchs Doratodus, P seudodalatias, Raineria? ), quickly (Reif, I97 8a). Reif (I97 8a) very tentatively attributed replaced by true neoselachians. this family to the Hybodontoidea, but there are no Raineria osswaldi is known only by an almost convincing arguments to do so (Capp etta, I98l). complete rostrum from the Rhaetic of Austria. ft was Pseudodalatias barnstonensis is quite a common referred to as Raineria nov. gen. by Osswald (1928), I2 CUNY -- PRIMITIVE NEOSELACHIAN SHARKS who did not give a species name to the specimen. NEW DATAABOUT UPPER TRIASSIC Cappetta (1987) has proposed Raineria osswaldi. NEOSELACHIAN SHARKS. The elongated rostrum of this speciesis quite similar to that of the Pristiophoridae, Sclerorhynchidae and I haverecently undertaken a systematic surveyof Pristidae and shows dermal denticles of the placoid the ultrastructureof the enameloidof isolatedteeth morphotype (Duffin, 1981; Cappetta, 1987). This led from the Upper Triassic of Western Europe. This Duffin (1981) and Thies and Reif (1985) to consider leadsto the recognitionof triple-layeredenameloid in Raineria as a neoselachian shark. Cappetta (1987) species hitherto thought to belong to the pointed out, however, that the oldest members of the Hybodontoide.There is "Hybodus"mino4 and also a three families Pristiophoridae, Sclerorhynchidae and speciesnot yet officially named,but appearingsome- Pristidae did not appear before the Albian and the times as " Pseudocetorhinuspickfordi" (Delsate &. elongated rostrum of Raineria would therefore be the Lepage,1991 ; Cuny, 1993b),and usually considered result of convergence. Moreover, contrary to the to be a hybodont.There is alsoa new species,which more recent families, the rostrum possessessharp will be describedin detailelsewhere, from Grozon,in lateral edges, probably devoid of rostral teeth the FrenchJura. (Capp etta, 1987). Placoid scales appear in all Neoselachii and pre-Rhaetic Hybodontoidea accor- ding to Reif (1978b). However the distribution of this character is insufficiently known to allow its use for taxonomic pu{poses (see above in Acronemus and Hopleacanthus for example). Cappetta ( 1987) stated I that "It is not impossible that the rostrum of Raineria belongs to the selachian of doubtful affinities.... PseudodalatiasReif." and so he considersit as a pos- sible Hybodontoidea. There is no direct evidence of 0,5 mm the association of Raineria and Pseudodalatias.The -rE latter is known in the Rhaetic of Great Britain, Belgium and France, and in the Norian of Lomb ardy, but was never recorded in the Rhaetic of Austria. Moreover, Cappetta (1987) also pointed out some similarities in the shape of the teeth of Reifia minuta to those of the Sclerorhynchidae, but he did not consider an association Reifia/Raineria. Without more complete material, it is impossible to state the real affinities of Raineria. Duffin ( 1981) considers that Steinbachodus estheriae Reif, 1980 approaches the neoselachian condition as its teeth show considerable differentia- tion of the crown. The root is of hybodontid organi- /N sation and vascularisation, and the crown displays only a SCE (Reif, 1980). Cappetta (1987) pointed out, moreover, similarities between the anterolateral teeth of Steinbachodus and those of Polyacrodus. I agree with Cappetta that Steinbachodus is a true Fig. 5: Tooth of "Hybodus" minor from the Rhaetic of Saint- Germain-les-Arlay (Jura, hybodontoid. France) in A: labial, B: apical and C: lingual views. Fig. 5: Dent d"'Hybodus" minor provenant du rhétien de Saint-Germain-1es-Arlay(Jura,France) en vuesA: labiale, B: apicaleet C: linguale. t3 ORYCTOS.VOL. 1. 1999

Teeth of "Hybodus" minor from Aust (Westbury I993a,Storrs 1994; Cuny et al.,1994;Cuny,I995b), Formation, England, fig. 4A-D), Habay-la-Vieille forming what Maisey (I975, I97l) calleda lingual (Grès de Mortinsart, Belgium), Medernach torus(figs . 4A, B, 5B). On the lingualface, the root (Steinmergelgruppe, Luxembourg), Syren (Rhaetic, is penetratedby numerous,small, irregularly distri- Luxembourg), and Saint-Germain-1es-Arlay(Groupe butedvascular foramina (fig. 4B-,D). des calcaires marneux et des "schistes noirs" du Rhétien, France, fig. 5) have been studied. All these teeth show a triple-layered enameloid with surface Fig. 6: A: Pseudodalatiasbarnstonensis, Rhaetic of Habay- la-Vieille, Belgium, tooth etched 10s in I07o HCl. SLE (fiS. 6BoC, D), a middle PFE (fig. 68, G) and E Ultrastructure of the enameloid showing single, randomly an internal TFE (fig. 6H)" J. Day has independently oriented crystallitesof apatites.B-H: "Hybodus" minon B: reached sirnilar conclusions with teeth of "Hybodus" Remnant of the SLE at the surface of a tooth etc\d 5s in minor coming fronn Aust (J. Day, pers. com.). I07o HCl. C: Thick SLE at the level of a ridge ornamenting However, some irnportant differences exist in the the surfaceof the crown, tooth etched 20s in I07o HCl. The layering of "Hybodl,ts" minor. At the level of the SLE has disappearedfrom the other part of the crown, sho- wing the underlying PFE. D: Thick SLE at the level of the ridges ornamenting the crown, the SLE is thicker cutting edge of a tooth etched 10s in I07o HCl. E: Ridge at than in other parts of the crown (fig. 6C, D). Below the surfaceof the crown of a tooth etched lmn in I07o HCl, this thick SLE. the PFE shows an unusual feature as with the SLE removed, showing the changein orientation of the bundles cf fibres show a change in orientation, the bundles of fibres of the PFE. F: PFE at the surface of the becoming perpendicular to the axis of the ridges crown of a tooth etched30s in 57o HCI + 1mn in I07o HCl. rather than being oriented in a basal-apical direction G: PFE at the level of the ridges of a tooth etched35s tn l07o HCl. H: Inner TFE at the apex of a tooth etched6 mn in 107o (fig . 6F,.G). This is very similar to the condition des- HCl. B,G from the Rhaetic of Saint-Germain-1es-Arlay(Jura, cribed in Hueneichthyscostatus by Reif (1977, see France), C from the Norian of Medernach (Great-Duchy of above). However, there is not a true extra layet, but a Luxemburg), D,H from the Rhaetic of Aust (South gradual change of orientation of the bundles of fibres Gloucestershire,England), E from the Rhaetic of Syren at the level of each ridge. This could also be the case (Great-Duchy of Luxemburg), F from the Rhaetic of Habay- in Hueneichthvs costatu.ças the detail of the structu- la-Vieille (Belgium). All the photographsrepresent the surfa- ce of the teeth after etching. re in the figure provided by Reif (1917, fig . 4) is mas- ked by numerous radial fibres. The TFE layer was Fig. 6: A: Pseudodalatiasbarnstonensis, rhétien d'Habay-la- shown to exist with certainty only in teeth coming Vieille, Belgique, dent attaquée10s dans de I'HCI dilué à from Aust, Syren. and Saint-Germain-1es-Arlay. I0To. Ultrastructure du pseudo-émailmontrant des cristaux Teeth from Habay-la-Vieille and Medernach have not simples,orientés au hasard.B-H: "HybodLts"minon B: Restes yet been checked in this regard. When the surface of du SLE à la surfaced'une dent attaquée5s dansde I'HCI dilué à I07o. C: SLE épaissiau niveau d'uneride d'ornementation the teeth is etched with diluted HCl, TFE seemsto be de la couronned'une dent attaquée20s dans de I'HCI dilué à restricted to the upper third of the crown only, as in rc%. Le SLE a disparu sur les autresparties de la couronne, the teethfrom Saint-Nicolas-de-Port(see above). It is découvrantle PFE sous-jacent.D: SLE épaissiau niveau de possible that the species "Hybodus" minor, difficult la carèned'une dent attaquée10s dans de I'HCI dilué à L07o. to distinguish from Rhomphaiodon nicolensis on a E: Ride d'ornementationà la surfaced'une dent attaqué,e1mn morphological basis,is also presentat this site. Some dans de I'HCI, et dont le SLE a été enlevé,montrant le chan- gement d'orientationdes faisceauxde fibres du PFE. F: PFE sectionsmade in teeth from Aust show, however, that à la surfaced'une dent attaquée30s dans de l'HCl dilué à 57o a TFE also exists at the baseof the crown. The reason et 1mn dans de I'HCI dilué à I07o. G: PFE au niveau d'une why this basal TFE never show up with surface ride d'ornementationd'une dent attaquée35s dans de I'HCI etching, while the apical one do, is unclear. There dilué à I}Vo. H: TFE interne à I'apexd'une dent attaquée6 mn may have been a problem with the preparation of the dans de I'HCI dilué à I07o. B,G provenant du rhétien de teeth and further work is needed to check this. Saint-Germain-1es-Arlay(Jura, France), C du Norien de Medernach (Grand-Duchéde Luxembourg), D,H du rhétien The vascularisation of the teeth of "Hybodbrs" d'Aust (South Gloucestershire,Angleterre), E du rhétien de minor is also interesting. As noted earlier by several Syren (Grand-Duchéde Luxembourg),F du rhétien d'Habay- authors,the root of "Hybodus" minor is lingually pro- la-Vieille (Belgique).Toutes les photographiesont êté prises jected (Woodward, 1889; Maisey, 1977; Duffin, en surfaceaprès attaque à I'acide.

T4 CUNY - PRIMITIVE NEOSELACHIAN SHARKS

Fig. 6

15 ORYCTOS,VOL. 1, 1998

The basal face is convex, with a depression teeth of Habay-la-Vieille show a triple-layered oriented mesio-distally and situated just under the enameloid, but it is quite different from that of the base of the crown. In this depression,there are some, two above-mentioned taxa. Firstly, the surface of the fewer than ten on average, open vascular canals. crown is mainly smooth. Therefore, the peculiar These canals become covered lingually and labially structure associated with the ridges in the above- and their openings on the labial side appear relative- mentioned taxa do not appear. Secondly, the SLE ly large, near the base of the root. In some teeth appearsthicker than in the teeth of "Hybodus" minor however, there is a very well-developed central fora- or Rhomphaiodon nicolensis. In these taxa, a bath of men, coffesponding to Casier (I947)'s "foramen five secondsin diluted HCI IÙVois enough to remove médio-externe" (fig. 4C). When the anterior part of most of the SLE, while in teeth of "Pseltdocetorhinus the root is worn awâ], which happen quite often, the pickfordi", 20 seconds are necessary to see the PFE base of the labial face appears corrugated, as in the (fig. 3G) appear near the apex of the crown, sugges- Synechodontiformes (Duffin 8. Ward, 1993; see the ting that the SLE is even thicker at the base of the figures 10, 11 8. 12 provided by Duffin, I993a). It is crown. Taking into account this unusual thickness, it probable that the pseudopolyaulacorhize state of the is unclear whether or not this SLE is homologous to Synechodontiformes arose from a "Hybodus" minor- that in modern neoselachians.In the Latter,this layer like anaulacorhize state. The appearanceof the cen- is very thin and seems only to prevent cracks appea- tral depression in the teeth of "Hybodus" minor ring in the PFE. It may have appeared secondarily. favoured the appearanceof open canals in the central On the other hand, the thick layer in "P. pickfordi" part of the root. The disappearance of the labial could be a remnant of the primitive SCE of the "wa11"on the basal face of the root will allow these Hybodontoidea. The appearanceand development of open canals to reach the labial side of the root, giving the SLE in modern sharks is far from being fully Cappetta's (1987) pseudopolyaulacorhize state. understood and much more work is needed before a "Hybodus" minor now appearsto be closely related convincing hypothesis is reached.The TFE (fig. 3H) to the Palaeospinacidae. has been found in the upper third of the teeth only, as A new speciesrecently found at Grozon (Cuny et in "Hybodus" minon The roots of the teeth of "P. al., in press) displays the same structure of the pickfordi" are projected lingually (fi g. 4G), but show enameloid as in "Hybodus" minor (frg. 3E, F). Both an anaulacorhize state of vascularization, without any speciesare found together at this site, but the teeth of open canals. Foramina ate randomly distributed on the new species differ from those of "Hybodus" the whole surface of the lingual face of the root (fig. minor by the more labiolingually compressedcusps 4H) and at the base of the labial face (fig. 4E). with well-developed cutting edges and the absenceof It is striking that in the Upper Triassic teeth pos- lateral cusplets (fig .2I). Very reduced cusplets appear sessing a triple-layered enameloid in which the root in the more anterior teeth only (fig. 2H). The root is is well-preserved (Synechodus rhaeticus, projected lingually, but no open vascular canals were Rhomphaiodon nicolensis, "Hybodlts" minor, observed. The anaulacorhize vascularisation of the "PseLtdocetorhinuspickfordi", and the new species root appears more primitive than that of "Hybodus" from Grozon), all show a root enlarged lingually, and minor. projected at nearly a right angle from the axis of the I have studied the ultrastructure of the enameloid crown (the lingual torus of Maisey, I97 5). This cha- of teeth of "Psebtdocetorhinus pickfordi" from racter is known among Ctenacanthoidea (Maisey, Habay-la-Vieille (fig. 4F,,G, H) only, although these I97 5) and to a lesser extent among Hybodontoidea, teeth are also known to appear at Aust (pers. obs., although in the latter, this lingual torus is never as Duffin, pers. com.), Holwell (Duffin, pers. com.), well developed as in primitive neoselachians(see for Syren (Cuny et al., 1997), Attert (Duffin &. Delsate, example Egertonodus basanus, Patterson, 1966; 1993) and Saint-Germain-1es-Arlay (Cuny et al., Maisey, 1983; Maisey, 1987). It is highly probable 1994) (fig. 4F). As these teeth will soon be described that the reduced lingual torus of the Hybodontoidea is and officially named by C. Duffin (pers. com.), I shall a derived charaeter, and that the primitive not give a complete description of them here. The Neoselachii have retained the primitive condition.

t6 CUNY - PRIMITIVE NEOSELACHIAN SHARKS

The Ctenacanthoidea, on the other hand, seem to presence of "Hybodus" minor at Saint-Nicolas-de- have almost vanished by Upper Triassic times Port, where fin-spines of Nemacanthus monilifer are (Capp etta, 1987), and a revision of the teeth attribu- known (Cuny & Ramboer, I99I), could not be ruled ted to the ctenacanthPhoebodus in the Upper Triassic out at the present time, but need further investigation would certainly prove to be useful, as the real affini- (see above).The species "H." minor has to be remo- ties of these teeth appear unclear (Capp etta, 1987). ved from the genus Hybodus,but before a new genus The crown morphology is extremely similar in hybo- is created, it would be worth carefully investigating a donts and primitive neoselachians. V/hen it is not possible synonymy between Nemacanthusmoniliftr possible to check the enameloid ultrastructure, the and "Hybodus" minon presenceof a lingual torus may therefore be useful in If confirmed, this synonymy will demonstrate distinguishing between teeth of Hybodontoidea and that Nemacanthus is a primitive neoselachian, with those of primitive Neoselachii. no apomorphic characters in the fin-spines. On an other hand, Hybodus minor will be based on fin- spines only (Agas siz, 183343). As these fin-spines ''HYBODUS'' MINORANI) could also belong to the genus Lissodus, Hybodus NEMACANTHUS MONILIFER. minor is therefore a nomen dubium.

The hypothesis that the fin-spines of Nemacanthus moniliftr and the teeth of "Hybodl,ts" TRIASSIC minor belong to the sameanimal is an old idea appea- er I ring sporadically in the literature (Woodward, 1891 ? | Nozuo* ; IcARNIAN -'JF;*,o*1,*ouo* Sauvage,I90l; Priem, 1908; Maise], 1977; Storrs, | "Palaeospinax" I f|l I I'Hybodus'minor 1994; Cuny, 1995b). The main problem with this Neoselachii with a I G.oron species hybodont-like hypothesis,however, is that the teeth, although some- I Rhomphaiodon nicolensis architecture of the teeth times considered unusual for a hybodont (Maisey, I P s e udoce tor hinus p ic I{o rd i I Hueneichthys costatus

I9l7; Storrs, 1994), were thought to belong to a I Synechodus rhaeticus Neoselachii hybodont (Duffin, I993a), whlle Netnacanthusmoni- of unknown f Reifia minuta relationships lrfu was supposed to share affinities with either ?Neoselachii a vailisia coppi Ctenacanthoideaor Neoselachii (seeabove). The pre-

I namtrro ossrtatat sent work proves that the teeth of "Hybodus" minor Elasmobranchii of unknown I Pseudcdal.atiasbamsronensis did not belong to a hybodont, but to a neoselachian relationships I I I I I t I I I I lDorandustricuspidatus shark, with a vascularisationof the root more primi- tive than in Synechodzs (includin g Palaeospinax, see above). Interestingly, the fin-spines of Nemacanthus moniliftr also appear more primitive than those of Fig. 7: Stratigraphicdistribution of the Neoselachii and pos- Synechodus (Maisey, 1977). These teeth and fin- sibly related sharks in the Triassic showing the dramatic spines appear, moreover, to be associated on an radiation of the group after the Carnian (Nemacanthusmoni- almost regular basisin Belgium (Duffin et al., 1983), Irfu have been excluded becauseof a possible synonymy France (Cuny, 1995b), Germany (Schmidt, 1928), with "HybodLts"minor). Great Britain (Woodward, 1891; Storrs, 1994), and Fig. 7: Répartition stratigraphiquedes Neoselachii ainsi que Luxembourg (Duffin, I993a; Delsate, 1995; Cuny et des requins pouvant leur être apparentésdurant le Trias mon- al., 1997). Some exceptions can be explained as fol- trant leur nette radiation après le Carnien (Nemacanthus lows. moniliftr n'a pas êté pris en compte car il pourrait s'agir du The absence of Nemacanthus moniliftr in sites même qu"'Hybodus"minor). like Saint-Germain-1es-Arlay(Cuny et al., 1994) or Attert (Duffin & Delsate, 1993) seems to be directly related to the sorting of the sediment, these two sites having yielded millimetre-scale remains only. The

I] ORYCTOS,VOL. 1, 1998

CONCLUSION that Hueneichthys costattts, Rhomphaiodon nicolen- sis, Synechodus rhaetict,ts, "Hybodus" minon The Upper Triassic (Norian + "Rhaetian") of "PseLtdocetorhinuspicfurdi", and the new Grozon 'Western Europe has yielded at least seven different speciesare closely allied, but this hypothesisis based neoselachianspecies : on primitive characters only. If true, this lineage - Hueneichthys costatus would have been appeared at least in the Lower - Reifia minuta Triassic (Thies, 1982). The phylogenetic position of - Synechodusrhaeticus Reifia minuta is unclear. Together with the - Rhomphaiodon nicolensis Neoselachii, the post-Carnian faunas show the appea- "Hybodus" minor / Nemacanthusmoniliftr rance of strange, ephemeral forms such as (which could represent the same animal) Doratodus, Pseudodalatias, Raineria, and Vallisia. - new Grozon species Vallisia may be a true neoselachian, but the three "P sebtdo c eto rhinus " pickfordi " other genera appear to belong neither to the among which three (Synechodus rhaeticbts, Neoselachii, nor to the Hybodontoidea. The major "PseLtdocelorhinuspicfurdi" , and the new Grozon change in the selachian faunas at the CarnianNorian species)are still waitin g a complete description. Some boundary is not restricted to Europe, as shown by the species (Synechodus rhaetictls, "Hybodbls" minor ? study of dermal denticles in Canada (Johns, 1996). Nemacanthus monilifur and "PseLtdocetorhinus pick- However, dermal denticles do not allow analysis of fordi") are quite commoil, reflecting the growing this change from a taxonomic point of view. Before importance of the Neoselachii in the post-Carnian the Triassic, the evolution of the Neoselachii is hard- ecosystem (fig. 7). All of them share a similar ultra- ly known. The Middle Triassic Acronemus sharesthe structure of the enameloid, with at least a surface primitive structure of its fin-spines with the SLE and a middle PFE. The SLE often appearsthic- Neoselachii (mantle of shiny enameloid and lack of ker than in extent neoselachians (at the level of the posterior denticles), but the absenceof a triple-laye- ridges in "Hybodus" minor and the new Grozon spe- red enameloid in its teeth precludes its assignment to cies, ofl the whole crown in "Psebtdocetorhinuspick- the Neoselachii. fordi" and Synechodusrhaeticus) and very similar in The character "mantle of shiny enameloid and structure to the SCE of the Hybodontoidea. It is pos- lack of posterior denticles in the fin-spines" is there- sible that this Triassic SLE is not homologous to the fore a synapomorphy for Eunemacanthus + SLE of the extant sharks, but representsa remnant of Amelacanthus + Hopleacanthus + Acronemus + the primitive SCE that we find for example in Neoselachii, which therefore represents a clade Acronembts. In Synechodus rhaeticus, however, the whose appearance can be traced back into the thickness of the SLE in the posterior teeth appearsto Carboniferous. be a secondary adaptation towards a crushing diet. If Hopleacanthus possessesteeth with a triple- The TFE appears more variable in structure, consis- layered enameloid, it will be considered as a true ting of single, randomly oriented crystallites in Reifia neoselachian, but the exact relationships among and Rhomphaiodon, or displaying the modern pattern Eunemacanthus, Amelacanthus, Acronemus and the (randomly oriented bundles of fibres) in Synechodus Neoselachii are impossible to assessbecause of the rhaeticr,ts, "Hybodl,ts" minon "Pseudocetorhinus fragmentary nature of their fossil record. Finally, the picfurdi", and the new Grozon species.TFE remains isolated Palaeozoic teeth attributed to the Neoselachii unknown in Hueneichthys. (Mcmurdodus and Anachronistes) appear quite spe- Most of these teeth appear rather primitive in cialized when compared to most of the Triassic teeth appearance, with a crown shape rather similar to the which possess a hybodont-like architecture of the typical hybodont pattern (cusps rather blunt and crown and a well-developed lingual torus in the root. moderately compressed labio-lingually, with lateral This would suggest,but not prove, that they aîe more cusplets not well separated from the main cusp, likely the result of a convergence phenomenon than crown often heavily ornamented) and retaining a true neoselachian teeth. well-developed lingual torus in the root. It is possible

18 CUNY - PRIMITIVE NEOSELACHIAN SHARKS

ACKNOWLEDGEMENTS RBFERENCES AGASSIZ,L. 1833-43.Recherches sur lespoissons fossiles. Tome 3 concernant I'histoire de I'ordre des Placoïdes. Imprimerie de I wish to thank J. Le Læuff and E. Buffetaut who Petitpierre, Neufchâtel, Switzerland, 390 + 34 pp. have suggested to me to do this article after the BENTON, M.J . 1991. What really happened in the ? Second European Workshop of Vertebrate Historical , 5: 263-278. Palaeontology.I also thank M.J. Benton, J. Day, D. BONI, A. 1937. Vertebrati retici italiani. Memorie dell'Academia dei Delsate, C. Duffir, P. Godefroit, G. Schaumberg and Lincei,6: 52I-719. C. Trueman who have shared unpublished data with CAPPETTA, H. 1987. Chondrichthyes 2. Mesozoic and Elasmobranchii. Handbook of Paleoichthyology, 38, Gustav ffie, as well as S. Powell and S. Kearns for their help Fischer Verlag, Stuttgart : l-I93. with the SEM. Special thanks are due to D. Delsate 1992. New observations on the palaeospinacid and P. Godefroit who provided to me numerous teeth dentition (Neoselachii, Palaeospinacidae).Neues Jahrbuch fiir from Belgium and the Grand-Duchy of Luxemburg Geologie und Palciontologie,Monatshefte : 565-570. for study. T. Borne, J. Enos, E. and G. Pennetier have DUFFIN, C.J. &ZIDEK, J. 1993.Chondrichthyes; sacrified some teeth from their private collections to pp. 593-609. In BENTON, M.J. (ed.) The fossil record 2. Chapman & Hall, London. allow me to check the ultrastructure of the enameloid CASIER, E. 1947. Constitution et évolution de la racine dentaire des in more recent hybodonts and neoselachians than . 3. Evolution des principaux caractères morpholo- those described in this study. To theffi, I also expres- giques et conclusions. Bulletin du Musée royal d'Histoire sed very special thanks. I won't forget M.J. Benton naturellede Belgique,23 (15): I-45. and D. Henderson who have greatly improved the CUNX G. I993a. Discovery of mammals in the Upper Triassic of English of the manuscript. This work has been fun- the Jura(France); pp. 95-99.IaLUCAS, S.G. & MORALES, M. (eds.) The Nonmarine Triassic. New Mexico Museum of Natural ded by the Marie Curie Fellowship ERBFM- History & ScienceBulletin,3. 8ICT950059 from the European Community and by 1993b. Evolution des faunes de vertébrés à la limite NERC grant GR 3|III24. Trias-Jurassique en France et au Luxembourg: implications à l'Europe occidentale. Thèse, Mémoire des Sciencesde la Terre n" 93.21, Université Pierre et Marie Curie Paris l-234. NOTE ADDED IN PROOH, 1995a.Apports du site de Lons-le-Saunier (Jura, France) à l'étude de la transgressionrhétienne dans I'Est de la France. Géobios,M.S. 18 : 113-L17. Since the submission of this manuscript, teeth of 1995b. Révision des faunes de vertébrés du site de Synechodus rhaeticus have been described (Duffin, Provenchères-sur-Meuse(Trias terminal, Nord-Est de la France). 1998b) but additionnal studies of the enameloid of Palaeovertebrata,24 (l-2): I 0 I - I34. teeth from Lons-le-Saunier and Holwell (Cuny, sub- 1995c. French vertebratefaunas and the Triassic-Jurassic mitted) have revealed a more complex structure than boundary. Palaeo ge o graphy, Palaeo climatolo gy, Palqeo e c olo gy, Llg : 343-358. the one described above. There are indistinct bundles _DELSAIE, D.; GODEFROII p.& ROCHE, M. 1997. fibres perpendicular the surface or parallel to it of to Syren, a new site from the Upper Triassic of Luxemburg. Second but perpendicular to the axis of the tooth. As these European Workshop of Vertebrqte Palaeontology, Esperaza- patterns are different from the usual neoselachian Quillan, abstracts. pattern, the exact relationships of Synechodusrhaeti- 4ARTIN M., RAUSCHER R., MAZIN J.-M. in press.A cus are still enigmatic. Teeth of Pseudocetorhinus new neoselachianshark from the Upper Triassic of Grozon (Jura, France). Geological Magazine, 133 (7). picfurdi have also been describedby Duffin (1998a) +AZIN, J.M. & RAUSCHER, R. 1994. Saint-Germain- as a lamniform neoselachianshark, close to the extant les-Arlay: un nouveau site rhétien daté par la palynologie et , Cetorhinus maximus.Teeth of the new l'étude des vertébrés dans le département du Jura (France). species from Grozon have been named Grozonodon Paléobiologie,14 (1): 35-48. candaui (Cuny et al., in press). Finally, Johns et aI. & RAMBOER, G. 1991. Nouvelles donnéessur la faune (1997) have published a review of the Triassic et l'âge de Saint-Nicolas-de-Port. Revue de Paléobiologie, 10 (1):69-78. Canadian shark teeth and dermal denticles which DE CARVALHO, M.R . 1996. Higher-level elasmobranchphylogeny, present complete the work. basal squaleans,and paraphyly; pp. 35-62.1n STIASSNX M.L.; PARENTI, L.R. & JOHNSON, G.D. (eds.)Interrelationships of . Academic Press,San Diego. T9 ORYCTOS,VOL. 1, 1998

DELSATE, D. 1995.Chondrichthyens mésozoïques du Grand Duché 6Il-619. In BENTON, M.J.(ed.) Thefossil record 2. Chapman de Luxembourg;pp. 11-12.In HERMAN, J. & VAN WAES, H. & Hall, London. (eds.) Elasmobranches et stratigraphie. Belgian Geological GAUDIN, T.J. 199I. A reexamination of elasmobranchmonophyly Survey,Professional Pape4 278. and chondrichthyes phylogeny. Neues Jahrbuchfiir Geologie -& LEPAGE, J.C. I99I. Requins et raies en Lorraine. und Palciontologie,Abhandlungen, 182 (2) : 133-160. Géolor, 3: 6-9. GUNNELL, F.M. 1933. Conodonts and remains from the DUFFIN, C.J. 1980. A new euselachian shark from the Upper Cherokee,Kansas City, and Wabaunseegroups of Missouri and Triassic of Germany. Neues Jahrbuch fiir Geologie und Kansas. Journal of Paleontology, T : 261-297. Palciontologie, Monatshefte : l-16. GODEFROIT, P. 1997. Reptilian, and mammalian teeth -1981. Comments on the selachiangenus Doratodus from the Upper Triassic of Varangéville (northeasternFrance). Schmid (1861) (Upper Triassic, Germany). Neues Jahrbuch Bulletin de l'Institut royal des Sciencesnaturelles de Belgique, fiir Geologie und Palciontologie,Monatshefte : 289-302. Sciencesde la Terre,67 : 83-I02. -I982a. A palaeospinacid shark from the Upper HENRY, J. 1876. Etude stratigraphique et paléontologique de Triassic of South-West England. Zoological Journal of the I'Infralias dans la Franche-Comté. Mémoire de la Société Linnean Societv,74 : I-7 . d'Emulation du Doubs, 4 (10): 285-476. -19gïA. Teeth of a new selachian from the Upper HUENE, F. von 1933. Zur Kenntnis des Wtirttembergischen Triassic of England. Neues Jahrbuch fiir Geologie und Râtbonebeds mit Zahn-funden neuer Sâuger und sâu gerâhnlicher Pakiontologie,Monatshefte : 156-166. Reptilien. Jahershefte des Vereins fu, vaterlandische -I993a. Mesozoic chondrichthyan faunas. 1. Middle Naturkunde inWiirttemberg, 89 : 65-I28. Norian (Upper Triassic) of Luxembourg. Palaeontographica,A, JOHNS, M.J. 1996. Diagnostic pedicle featuresof Middle and Late 229 : 15-36. Triassic elasmobranch scales from northeastern British -1993b. Late Triassic sharks teeth (Chondrichthyes, Columbia,Canada. Micropaleontology, 42 (4): 335-350. Elasmobranchii)from Saint-Nicolas-de-Port(north-east France); -BARNES C.R., ORCHARD, M.J. I99l - pp. I -32. In HERMAN, J. &. VAN WAES, H. (eds.) and biostratigraphy of Middle and Late Triassic elasmobranch Elasmobranches et stratigraphie. Belgian Geological Survey, ichthyoliths from northeastern British Columbia. Geological P rofes sional Paper, 264. Surveyof Canada,Bulletin, 502 : l-235. -1998a. New shark remains from the British Rhaetian MAISEY, J.G. 1975. The interrelationships of pholacanthous (latestTriassic). 1. The earliestbasking shark.Neues Jahrbuch selachians. Neues Jahrbuch fiir Geologie und Palciontologie fiir Geologie und Palciontologie,Monatshefte : I57-181. Monatshrft, : 553-567. -1998b - New sharkremains from the British Rhaetian 1977. The fossil selachian fishes Palaeospinax (latest Triassic). 2. Hybodonts and palaeospinacids.Neues Egerton I8l2 andNemacanthus Agassiz 1837. Zoological Jahrbuch fiir Geologie und Palciontologie, Monatshefte : Journal of the Linnean Sociee, 60 : 259-273. 240-256. 1981.Studies on the Paleozoicgenus Ctenacanthus -COUPNTEZ, P., LEPAGE, J.C. &, V/OUTERS, G. Agassiz. n 1: Historical review and revised diagnosis of 1983.Rhaetian (Upper Triassic)marine faunasfrom "le golfe du Ctenacanthus with a list of referred taxa. American Museum Luxembourg" in Belgium (preliminary note). Bulletin de la Novitates.2TlS: I-22. Sociétébelge de Géologie,92(4): 3 t 1-315. 1982. Studies on the selachian genus -&. DELSATE, D. 1993.The age of the Upper Triassic Ctenacanthus Agassiz. No 2. Bythiacanthus St John and vertebrate fauna from Attert (Province of Luxembourg, Worthen, Amelacanthus, new genus, EunemacanthusSt John Belgium); pp. 33-44.1n HERMAN, J. & VAN WAES, H. (eds.) and Worthen, SphenacanthusAgassiz, and Wodnika Mi.inster. Elasmobrancheset stratigraphie. Belgian Geological Survey, American Museum Novitates.2722 : l-24. P rofes sional Pape4 264. 1983. Cranial anatomy of Hybodus basanus -RICHTER, M. & NEIS, P.A. 1996. Shark remains Egerton from the Lower of England. American from the Late Carboniferous of the Amazon Basin, Brazil . Neues Museum Novitates, 2758 : I-64. Jahrbuchfu, Ge olo g i e und Paldontologie M onats heft e : 232-256. 1984. Chondrichthyan phylogeny: A look at the -&LWARD, D.J. 1983.Neoselachian sharks'teeth from evidence.Journal of VertebratePaleontology, 4 : 359-31I. the Lower Carboniferous of Britain and the Lower Permian of 1985. Cranial morphology of the fossil elasmo- the U.S.4. Palaeontology,26 (1): 93-110. branch Synechodusdubrisiensis. American Museum Novitates, 1993. The palaeospi- 2804 : I-28. nacid sharks of Lyme Regis, southernEngland. pp. 53- 102. In 1987. 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