Journal of Vertebrate Paleontology 30(1):57 67, January by the Society of Vertebrate Paleontology ARTICLE

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1 Journal of Vertebrate Paleontology 30(1):57 67, January by the Society of Vertebrate Paleontology ARTICLE RHOMBICHTHYS INTOCCABILIS, GEN. ET SP. NOV. (ELLIMMICHTHYIFORMES, CLUPEOMORPHA, TELEOSTEI), FROM THE CENOMANIAN (UPPER CRETACEOUS) OF EIN YABRUD, MIDDLE EAST: ANATOMICAL DESCRIPTION AND PHYLOGENETIC IMPLICATIONS BOUZIANE KHALLOUFI,,1 RENÉ ZARAGÜETA-BAGILS, 2 and HERVÉ LELIÈVRE 1 1 Muséum national d Histoire naturelle, CR2P UMR 7207 Centre de Recherches sur la PaléobiodiversitéetPaléoenvironnements, 57 rue Cuvier, CP 38, F-75005, Paris, France, khalloufi@mnhn.fr, lelievre@mnhn.fr; 2 Université-Pierre et Marie Curie-Paris 6, CR2P UMR 7207 Centre de Recherches sur la Paléobiodiversitéetles Paléoenvironnements, MNHN Department Histoire de la Terre Bâtiment de Géologie, CP48, 57 rue Cuvier, F-75005, Paris, France, Rene.Zaragueta Bagils@upmc.fr ABSTRACT A new double-armored member of the Ellimmichthyiformes (Clupeomorpha, Teleostei) is described from the Cenomanian (Upper Cretaceous) of Ein Yabrud, near Ramallah, Middle East. The anatomical description of Rhombichthys intoccabilis, gen. et sp. nov., is based on 13 subcomplete or incomplete acid-prepared specimens. This taxon shows several remarkable characters such as an important dorsoventral elongation of the lateral wings of the ventral scutes that give an apex-shaped ventral profile in the biggest specimens. Some dorsal fin rays are very extended and branched, and the dorsal fin extends along the major part of the dorsal margin of the body. Rhombichthys intoccabilis, gen. et sp. nov., shares the synapormorphies of the family Paraclupeidae and the subfamily Paraclupeinae. It appears closely related to the genera Triplomystus and Ezkutuberezi, mainly in the basis of the shape of dorsal and ventral scutes and the absence of a hypural diastema. INTRODUCTION The ichthyofauna of the Cenomanian Tethys is known from numerous taxa collected from deposits in Lebanon (Hakel, Hajula, Namoura), Portugal (Laveiras), Morocco (Jbel Tselfat, Kem Kem beds), Slovenia (Komen), etc. These taxa belong to Chondrichthyes, Holocephali, Sarcopterygii, and Teleostei (Forey et al., 2003). Each site shows a high proportion of endemic taxa. Ein Yabrud is a locality situated about 7 km to the northeast of Ramallah, Palestine, at an altitude of m (Fig. 1), in the Middle East. The rocks here are composed of a series of thin laminated limestone. This kind of sediment indicates a shallow and low-energy marine platform depositional environment (Gayet, 1980; Chalifa and Tchernov, 1982; Polcyn et al., 1999). The stratigraphic position of Ein Yabrud remains a little uncertain; it has been attributed to the Bet Meir Formation or to the Amminadav Formation (Fig. 2). The age of these formations extends from the early up to the middle Cenomanian (Chalifa and Tchernov, 1982; Chalifa, 1989a, 1989bb; Polcyn et al., 1999; Rieppel et al., 2003). Knowledge about this locality has been synthesized by Polcyn et al. (1999) and Rieppel et al. (2003). A number of taxa have already been described from Ein Yabrud. These include one species of Amiiformes (Pachyamia latimaxillaris Chalifa and Tchernov, 1982), two of Dercetidae (Hastichthys gracilis (Chalifa, 1989c), Dercetoides venator Chalifa, 1989c), two of Gonorynchidae (Judeichthys haasi Gayet, 1985, Ramallichthys orientalis Gayet, 1982), two of Enchodontidae (Enchodus brevis Chalifa, 1989b, Parenchodus longipterygius Raab and Chalifa, 1987), one of Eurypholidae (Saurorhamphus judeaensis Chalifa, 1985), one of Halecidae (Serrilepis longidens Chalifa, 1989a), one of Pharmacichthyidae (Pharmacichthys judensis Gayet, 1980), two of Aipichthyidae (Aipichthyoides galeatus Gayet, 1980, Aipichthyoides formosus Gayet, 1980), one * Corresponding author. of Trachichthyoidei incertae sedis (Judeoberyx princeps Gayet, 1980) and one of Enchondotoidei incertae sedis (Yabrudichthys striatus Chalifa, 1989a). The other vertebrate fossils include a pleurodire turtle, Bothremys parva (Haas, 1978), a mosasaur (Haasia gittelmani Polcyn et al., 1999), and some hind-limbed snakes (Pachyrachis problematicus Haas, 1979, Haasiophis terrasanctus Tchernov et al., 2000). Gayet (1986:5) noticed that fossil specimens from Ein Yabrud often show a post-mortem fusion of some bones that takes place during the fossilization process. As a result, the bone sutures are masked, making the description of the shape and morphological details of the bones quite difficult. In contrast, the axial and caudal skeletons do not seem affected, are well preserved, and show many details. However, fossils from Ein Yabrud are more crushed and not as well preserved as those from Lebanese localities. Rhombichthys intoccabilis, gen. et sp. nov., is the first clupeomorph fish described from Ein Yabrud. It does not seem to be an uncommon taxon in the locality because 13 specimens were available for this study, and another specimen probably belonging to this species was figured by Frickhinger (1991:549). MATERIALS AND METHODS Rhombichthys intoccabilis, gen. et sp. nov., is represented in the study collection by 13 specimens, including one in part and counter-part. A caudal skeleton, probably belonging to this species, is also studied. The specimens were lent for study to Mireille Gayet. The fossils are preserved in limestone, which permits a chemical preparation according to the transfer method (Toombs and Rixon, 1950). This involves embedding the specimen in a polyester resin and dissolving the matrix using a 10% acetic acid solution, reduced to 5% after the skeleton appears. Some specimens were stained with Alizarin in order to bring out the bone structures, and magnesium oxide or ammonium 57

2 58 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 1, 2010 FIGURE 1. Map of the area of Ein-Yabrud (after Chalifa and Tchernov, 1982, modified). chloride was used to emphasize relief in some photographed specimens. Observations and camera lucida drawings were done using a CETI binocular. Sometimes, a partial immersion within ethanol was used to observe some details of the anatomy. Institutional Abbreviations CNRS, Centre national pour la recherche scientifique; HUJ, Hebrew University of Jerusalem; MNHN,Muséum national d Histoire naturelle, Paris. Anatomical Abbreviations Abbreviations followed by (R) or (L) refer to a right or left bone, respectively. Act, actinost; Ang-art, anguloarticular; Asph, autosphenotic; pr.bpt, basipterygoid process; Bb, basibranchial; Bb.t, basibranchial teeth; B.r, branchiostegal rays; Ch.a, anterior ceratohyal; Ch.p, posterior ceratohyal; Cl, cleithrum; Co, coracoid; De, dentary; DS, dorsal scutes; Ecpt, ectopterygoid; Enpt, endopterygoid; Ep, epural (numbered); Epo, epiotic; Fr, frontal; H, hypural (numbered); Hs.Pu, haemal spine of preural centra (numbered); Hm, hyomandibula; Hh.d, dorsal hypohyal; Hh.v, ventral hypohyal; imp.cen, impression of underlying centrum; Io, interopercle; L.e, lateral ethmoid; md.s.c, mandibular sensory canal; Mes, mesethmoid; Mpt, metapterygoid; Mx, maxilla; Ns.Pu, neural spine of preural centra (numbered); o.md.s.c, opening for the mandibular sensory canal; o.ot.s.c, opening for otic sensory canal; Op, opercle; Ors, orbitosphenoid; Oth, otholith; Pa,parietal;Pal, palatine; Ph, parhypural;php,parhypurapophysis;pmx, premaxilla; Pop,preopercle;pop.s.c, preopercle sensory canal; P.r, pelvic rays; Pro, prootic; Psph, parasphenoid; Pts, pterosphenoid; Pto, pterotic; Ptt, post-temporal; Ptt.foss, post-temporal fossa; Pu, preural centrum (numbered); Q, quadrate; Rar, retroarticular; Sca, scapula; Scl, supracleithrum;smx, supramaxilla (numbered); Sn, supraneural; Soc, supraoccipital; Sym, symplectic; U, ural centrum (numbered); Uh, urohyal; Ur, uroneural (numbered). Other Abbreviations ac. prep., acid prepared; p. & cpt., part and counterpart. FIGURE 2. Chronostratigraphic section of the Judea Group (redrawn after Chalifa and Tchernov, 1982).

3 KHALLOUFI ET AL. A NEW DOUBLE-ARMORED ELLIMMICHTHYIFORM 59 Materials Examined Clupeomorpha incertae sedis: Armigatus brevissimus (de Blainville, 1818), Cenomanian, Hakel, Lebanon MNHN HAK481 (ac. prep.), HAK654 (ac. prep.); Scombroclupea macrophthalma (Heckel, 1849), Cenomanian, Hakel, Lebanon MNHN HAK437. Paraclupeidae: Diplomystus birdi Woodward, 1901: Cenomanian, Hajula, Lebanon MNHN 320a, b (p. & ctp.), 321a, b (p. & ctp.); Diplomystus dubertreti Signeux, 1951, Santonian, Sahel Alma, Lebanon MNHN SHA 2052, SHA 2053; Diplomystus solignaci Gaudant and Gaudant, 1971, Senonian, Gabes, Tunisia, MNHN ; Rhombichthys intoccabilis, gen. et sp. nov., Cenomanian, Ein Yabrud, Palestine, HUJ 603F, EY 603Z, EY604G, EY606d, EY608P, G (p. & cpt.), EY610, EY611, EY613Y, EY614, EY616A, EY617Q; Sorbinichthys elusivo Bannikov and Bacchia, 2001, Cenomanian, Namoura, Lebanon, MNHN NRA 40, NRA 61, NRA 62, NRA 102 (ac. prep.); Triplomystus Forey et al., 2003, Cenomanian, Namoura, Lebanon MNHN NRA 6 (ac. prep.), NRA 7 (ac. prep.), NRA9 (ac. prep.), NRA 25a (ac. prep.), NRA 25b, NRA 27, NRA 39, NRA 89; Triplomystus noorae Forey et al., 2003, Cenomanian, Namoura, Lebanon MNHN NRA76. Clupeidae: Alosa alosa (Linnaeus,1758), MNHN A 7391, D-16 (study collection of P. Béarez, MNHN-CNRS), Ethmidium maculatum (Valenciennes, 1847), 5105 (study collection of P. Béarez, MNHN-CNRS). Pristigasteridae: Ilisha fuerthii (Steindachner, 1875), 6780 (study collection of P. Béarez, MNHN-CNRS), Pellona castelnaeana Valenciennes, 1847, 524 (study collection of P. Béarez, MNHN-CNRS). SYSTEMATIC PALEONTOLOGY CLUPEOCEPHALA Patterson and Rosen, 1977 Subdivision CLUPEOMORPHA Greenwood et al., 1966 Order ELLIMMICHTHYIFORMES Grande, 1982 Family PARACLUPEIDAE Chang and Chou, 1977 Subfamily PARACLUPEINAE Chang and Chou, 1977 RHOMBICHTHYS INTOCCABILIS, gen. et sp. nov. Etymology The generic name is from Rhombea (rhomb in Latin and old Greek) and refers to the general shape of the body and ichthys (fish in old Greek). The specific name is from toccare (to touch in Latin) and in-, a privative prefix, in reference to the well-protected body ( untouchable ). Holotype HUJ EY603F (Fig. 3). Additional Specimens HUJ EY603Z (Fig. 4), EY604G, EY606d, EY608P, and EY608G (p. & cpt.), EY609S, EY610, EY611, EY613Y, EY614, EY616A, EY617Q. Locality and Age Ein Yabrud, Palestine, Middle East; early to middle Cenomanian (Upper Cretaceous). Diagnosis Fish with deep body; ventral profile rounded (in smallest specimens) to acutely angled (in biggest specimens); dorsal profile with marked angle at insertion of first dorsal fin rays; two series of scutes; predorsal series of scutes ornamented by vermiculated ridges and with smooth edges; last predorsal scutes claw-shaped; ventral series of scutes with lateral wings very elongated dorsoventrally; posterior-most ventral scutes with two spines in their distal extremity, one posterior and one ventral; dorsal fin extending anteroposteriorly over major part of dorsal profile; first dorsal fin rays very elongated; first pairs of ribs deeply inserted into cavities in centra; posterior-most parapophysis gradually increasing in size to reach size of first haemal spines; no gap between hypurals. DESCRIPTION General Features The body (Fig. 5) is compressed, and deeper than long. In the largest specimens, the ventral profile is acute, because of the particular shape of the ventral scutes. The dorsal profile is more regular, but with a distinct angle at the insertion of the dorsal fin. The first dorsal fin rays extend considerably upwards. Braincase Although the braincase seems relatively well preserved in several specimens, a closer examination shows that it is always crushed and bones are always fragmented, making it difficult to assess bone contours and detailed anatomical analysis of this region. The parietals (Figs. 6 8) are subtriangular and enlarged in their posterior part. In specimen EY606D, some vermiculated wrinkles can be observed. The parietals appear to meet in the midline, not being separated by the supraoccipital. The supraoccipital (Figs. 6 8) presents a low median crest, often incomplete. The epiotic (Figs. 6 8) constitutes the posterodorsal margin of the neurocranium. In the holotype (Fig. 6), the epiotic seems to be broken and only its dorsal part is preserved. A cavity possibly corresponding to the post-temporal fossa is unearthed, and contains a smooth and spherical bone, possibly an otolith (note that it was not destroyed by the acid preparation) or an allogenous bone (tooth?). A longitudinal ridge traverses the pterotic and extends up to the frontals, pierced by a small foramen in its posterior end, probably an opening for the otic sensory canal (Fig. 7). The autosphenotic (Figs. 6 8) possesses a strong process. It is situated between the hyomandibula and the frontals, and forms the posterodorsal margin to the orbit. The prootic, partly visible in some specimens (Figs. 6 8), is positioned ventrally to the autosphenotic, near the hyomandibula. It appears subrectangular but the adjacent bones obscure its exact shape. The frontals (Figs. 6 8) are straight. Posteriorly, they are wide and some pores probably corresponding to the openings for the supraorbital sensory canal are visible (in the specimen EY614). A groove along the frontals indicates the passage of this canal. Ventrally, the frontals contact the pterosphenoid (Figs. 6 8) and the orbitosphenoid (Figs. 7, 8). Anteriorly, they are thinner and in contact with the mesethmoid (Figs. 6 8). The lateral ethmoid (Figs. 6 8) is located posteroventral to the mesethmoid and constitutes the anterior margin of the orbit. The mesethmoid bears two anterior lateral processes and appears Y- shaped. A slender bone, situated ventral to the mesethmoid in some specimens, may correspond to the nasal (Fig. 6), but the poor preservation of this area prevents better observations. The parasphenoid (Figs. 6 8) is elongated and bears a welldeveloped basipterygoid process (Figs. 7, 8). In some specimens (EY606D, EY608G), a foramen is observed posterior to this process, probably the foramen for the internal carotid artery (sensu Forey, 2004:Figs. 4, 5). No teeth are observed on the parasphenoid. Opercular Series The opercle (Figs. 6 8) is wide, with a rounded posterior edge bearing fine serrations and a slightly curved anterior margin, often hidden by the preopercle. The subopercle is partly visible under the opercle. The preopercle (Figs. 6 8) is incompletely preserved in all of the known specimens. It is elongated and L-shaped, with smooth margins and similar in shapetothoseofarmigatus and Triplomystus, but narrower than that of Scombroclupea macrophthalma. Its upper lamina overlaps the opercle and the hyomandibula and its horizontal lamina lies alongside the metapterygoid and the quadrate. The preopercular sensory canal (Figs. 7, 8) runs along the anterior edge of the preopercle, with some efferent branches. The interopercle is seen in the holotype (Figs. 6, 8), it is elongated anterodorsally; however, in this specimen it is very deformed and crushed. Hyopalatine Bones The quadrate (Figs. 6 8) is subtriangular with a prominent articulator condyle anteroventrally. In Rhombichthys, gen et sp. nov., and Triplomystus, the metapterygoid is placed more posteriorly relatively to the quadrate than in

4 60 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 1, 2010 FIGURE 3. Lateral view of Rhombichthys intoccabilis, gen. et sp. nov., holotype, HUJ EY603F. Scale bar equals 6 cm. Armigatus or Diplomystus, where the metapterygoid is more dorsal. The palatine is partly visible in the holotype (Fig. 6), between the maxilla and the premaxilla. The symplectic (Fig. 8) is a long and thin bone lodged within a gutter in the quadrate. The metapterygoid (Figs. 6 8), large and subtriangular, expands from the quadrate to the hyomandibula. The endopterygoid (Figs. 6 8) is semicircular; it is in connection dorsally with the parasphenoid and ventrally with the quadrate and the metapterygoid. It has numerous teeth over its surface, visible on the specimen EY611. The ectopterygoid (Figs. 6 8) is overlapped anteriorly by the supramaxillae, partially obscuring its shape. Nevertheless, it seems to be a slender and bowed bone. The hyomandibula (Figs. 6 8) is partially hidden by the preopercle. In the holotype (Fig. 6), its dorsal surface shows a double-headed condyle, in contrast to Triplomystus where the hyomandibula presents a single articulation process (Forey et al., 2003). Jaws The upper jaw is composed of a maxilla, two supramaxillae, and a premaxilla (Figs. 6 8). The maxilla has the usual shape seen in Clupeomorpha, a rounded and thick posterior part associated with a thinner and straight anterior part articulating with the premaxilla. Dorsally, the maxilla is partially covered by the two supramaxillae and is ornamented by deep grooves. The anterior supramaxilla is oval. The posterior supramaxilla is also oval with an elongated anterior process. The two supramaxillae are ornamented, with fine longitudinal serrations. The premaxilla is small, oval, anteriorly rounded, and in close contact with the maxilla. The dentary is deep (Figs. 6 8). The mandibular sensory canal (Figs. 7, 8) runs within a longitudinal ridge pierced by small openings. The anguloarticular (Figs. 6 8) is large and forms the glenoid that articulates with the condyle of the quadrate. It shows some arc-shaped ornamentation and an opening for the mandibular sensory canal (Figs. 6, 8). The anterior part of the anguloarticular is elongated to partially cover the dentary, and

5 KHALLOUFI ET AL. A NEW DOUBLE-ARMORED ELLIMMICHTHYIFORM 61 FIGURE 4. Lateral view of Rhombichthys intoccabilis, gen. et sp. nov., HUJ EY603Z. Scale bar equals 2 cm. The size and the shape of the specimen may indicate it is a juvenile. marked by a deep furrow. A small oval retroarticular (Fig. 8) is seen in some specimens. No teeth are observed on maxilla, premaxilla, or dentary. Hyoid Arch and Gill Arches The hyoid arch is partially visible in only some specimens. It is often displaced and badly preserved. The anterior ceratohyal (Figs. 6 8) is never completely seen. It appears hourglass-shaped and pierced by a beryciform foramen, as in Triplomystus. The posterior ceratohyal (Fig. 6) is also visible posterior to the anterior ceratohyal, but its shape is uncertain. Dorsal and ventral hypohyals (Fig. 6) are subtriangular and of equal size; they show a small depression in their anterior part. Posteriorly, the urohyal (Fig. 6) is present, and is subtriangular with a prominent condyle anteriorly. It is crossed medially by a low ridge and resembles that of Ellimma branneri (Chang and Maisey, 2003:10, Fig. 5A). In some specimens, the basibranchial (Fig. 6) can be seen. It carries numerous rows of small teeth. About six branchiostegal rays (Figs. 6, 8) are observed, but their number might be higher. Infraorbital Bones Infraorbitals are poorly preserved. In some specimens, infraorbitals 3 and 4 are partially visible. Paired Girdles and Fins The pectoral girdle (Figs. 6 8) shows an elongated post-temporal. Its dorsal part is sharp and extended along the epiotic while its ventral part is constituted by a lamina, partly covering the supracleithrum. The supracleithrum is narrow but its shape is not precisely observable. The cleithrum is S-shaped and well developed; its upper part is anteriorly concave and borders the opercle; its lower part is anteriorly convex and stretches out anteroventrally. The coracoid is large. It connects posteriorly to the scapular, but this bone is not well preserved. There are about 14 pectoral fin rays. Some actinosts are visible, but their number cannot be determined (Fig. 7). The pelvic girdle is hidden by the ventral scutes; only some actinosts and the pelvic fin are visible (Fig. 5). It is located mid way along the ventral profile of the body. Only six rays are visible. Vertebral Column A total of 34 vertebrae is present, counted in the holotype, which is the only specimen with the complete series of vertebrae (Fig. 5). However, an exact count is difficult to establish because the first few are hidden by the opercle and the pectoral girdle. Among the vertebrae, 20 are abdominal and bear ribs. The other 14 vertebrae are caudal, of which two are urals. The centra are subrectangular in lateral view and larger in the middle of the series than in the extremities. The first 10 centra are marked by a longitudinal ridge that delimits two cavities. The next 21 centra present two longitudinal ridges and three cavities between them. The preural centrum is marked by two longitudinal grooves, and the two ural centra are marked by only one. Except for the ural vertebra, all centra are fused with their respective neural arch and spine. The lengths of successive neural spines slightly increase up to about the 14th vertebra, and gradually decrease posteriorly. As observed in Triplomystus noorae (Forey et al. 2003), the neural arches of Rhombichthys intoccabilis, gen. et sp. nov., are broad for some of the first vertebrae and become smaller and extended as two zygapophyses up to the 13th vertebra. Some of the first neural arches clearly show the foramen for the spinal artery. The parapophyses are fused to the centra. The first 10 are small and short. Their length increases up to the last abdominal vertebra, where the parapophysis reaches the length of the haemal spine carried by the first caudal centrum. Posteriorly, their size decreases. This particular pattern of the series of parapophyses is shared with Triplomystus and most other ellimmichthyiforms and it can be related to the peculiar insertion of the ribs: the first 10 pairs of ribs insert directly on the centrum; the others (11 pairs) are connected to the ventral end of the parapophyses. The size of the ribs decreases anteroposteriorly and the last ribs are often preserved slightly displaced and reversed. The relationship between the ribs and the ventral scutes is irregular, and often several ventral scutes are associated with a rib, whereas in Triplomystus and Diplomystus, each rib is associated exclusively with one ventral scute. Haemal spines are present from the 21st through the 31st vertebra and their length decreases posteriorly. Their length is comparable to that of the neural spine of the same centrum. A series of posteriorly elongated epineurals is visible in about the first 13 vertebrae. The longest ones extend along four centra. Some epipleurals are visible, carried by the parapophyses of the about the 11th to the 18th centra, but the series may be incomplete.

6 62 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 1, 2010 FIGURE 5. Reconstruction of entire skeleton of Rhombichthys intoccabilis, gen. et sp. nov., mainly based on the holotype, HUJ EY603F. Scale bar equals 1 cm. In some specimens, seven or eight supraneurals are preserved between the skull and the first dorsal pterygiophore (see Fig. 10). They are autogenous and slightly convex. Their length increases and their orientation becomes more vertical from the first to the posterior-most ones. Dorsal and Anal Fins The dorsal fin is very extended anteroposteriorly and covers about three-fifths of the dorsal profile (Fig. 5). In some other ellimmichthyiforms, such as Diplomystus dentatus, Triplomystus, Paraclupea, orellimma, the dorsal fin shows a restricted anteroposterior extension, often only one third of the dorsal profile. In Diplomystus birdi and D. dubertreti, the dorsal fin is extended. The dorsal fin insertion lies approximately at the level of the sixth vertebra. About 26 dorsal pterygiophores can be observed, up to the 23rd vertebra. Either one or two pterygiophores occupy each interneural space, except for the fifth one, which is unoccupied. A maximum of 15 dorsal fin rays, partly preserved, are apparent in the specimens. However, according to the number of pterygiophores, their number could reach about 25. The first dorsal fin ray is short and unbranched. The second one is about three times longer. Posteriorly, the rays are very long (about 95% of the SL for the three following rays) and their size decreases farther posteriorly. All dorsal fin rays are branched except the three anterior-most ones. The anal fin is located at the posterior region of the ventral profile; its insertion is found below the 20th vertebra. It is supported by 12 or 13 pterygiophores included between the 20th and

7 KHALLOUFI ET AL. A NEW DOUBLE-ARMORED ELLIMMICHTHYIFORM 63 Downloaded At: 10:18 12 February 2010 FIGURE 6. Skull of Rhombichthys intoccabilis, gen. et sp. nov., holotype, HUJ EY603F. A, photographic in lateral view; B, interpretative drawing. Abbreviations are as listed in Materials and Methods. Scale bar equals 1 cm. the 27th vertebra, but the exact number of rays remains unknown because this region is poorly preserved in all specimens. Caudal Skeleton and Fin The caudal skeleton is only completely preserved in the holotype (Fig. 9). In other specimens, the caudal skeleton is either absent or incomplete. The caudal fin is forked, with two slender and sharp lobes. It is supported by three preural and two ural centra, whose size decreases anteroposteriorly. The third preural centrum possesses a neural spine slightly longer than most caudal neural spines, and a stout hemal spine. The second preural neural spine is bifid (only on the holotype; this neural spine is not preserved in the other specimens). The splitting of the neural spine of preural centra is also encountered in the third preural centrum of Ez kutuberez i carmeni (after Poyato-Ariza et al., 2000). Taverne (2000) found a similar condition in Tselfatiiformes but he interpreted it as the presence two neural spines for a single centrum. It is generally intraspecific variation as described by Castro Leal and Brito (2007). In other ellimmichthyiforms, the neural spine of the preural centrum is relatively large, as noted by Patterson and Rosen (1977:fig. 37) in Ellimmichthys longicostatus. The neural and the hemal spines of the second preural centrum are about the same size as those of the third preural centrum. The preural centrum has a small neural spine and bears a robust autogenic parhypural. A small but well-visible parhypurapophysis is observed. The two ural centra are reduced in size and do not show neural or hemal spines. FIGURE 7. Skull of Rhombichthys intoccabilis, gen. et sp. nov., HUJ EY609S. A, photographic in lateral view; B, interpretative drawing. Abbreviations are as listed in Materials and Methods. Scale bar equals 1 cm.

8 64 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 1, 2010 Downloaded At: 10:18 12 February 2010 FIGURE 8. Reconstruction of the skull of Rhombichthys intoccabilis, gen. et sp. nov. Abbreviations are as listed in Materials and Methods. Scale bar equals 1 cm. There are two uroneurals. The first, longer one, runs from the preural centrum to the caudal fin rays. The second uroneural is shorter than the first and it is located ventral to it. Three slender epurals fill the space between the neural spine of the second preural centrum and the first uroneural. The number of hypurals remains uncertain. At least five hypurals are present, but the existence of a sixth one, the usual condition in ellimmichthyiforms, is possible. The first hypural is large and extends along the parhypural. It is triangular and shows a proximal and welldeveloped articular process in contact with the first ural centrum. The same shape is found in Armigatus brevissimus, Triplomystus, and some species of Diplomystus (Zaragu eta-bagils, 2004). As usual in clupeomorphs, the second hypural is fused to the first ural centrum (Grande, 1985). It is narrower than, and extends along, the first. The third, triangular, hypural is the largest of the series. It is in contact with the second ural centrum through an anterior condyle-shaped process. The fourth hypural reaches the second ural centrum; it is smaller than the previous hypurals. The fifth hypural is the smallest one observed. It is a bony rod situated between the fourth hypural and the second uroneural. No hypural diastema is present. The upper lobe of the caudal fin includes about 20 rays, distributed as 10 procurrent and 10 principal rays. The principal rays are segmented, and branched with at least one or two levels of dichotomy. Some of the procurrent rays are segmented, but the outer rays are unsegmented. The lower caudal fin lobe shows 14 rays, with 9 principal rays, segmented and branched. As for the upper lobe, some procurrent FIGURE 9. Caudal skeleton of Rhombichthys intoccabilis, gen. et sp. nov., holotype, HUJ EY603F. A, photographic in lateral view; B, interpretative drawing. Abbreviations are as listed in Materials and Methods. Arrows indicate the position of outer principal fin rays. Scale bar equals 1 cm.

9 KHALLOUFI ET AL. A NEW DOUBLE-ARMORED ELLIMMICHTHYIFORM 65 FIGURE 10. Dorsal scutes of Rhombichthys intoccabilis, gen. et sp. nov. A, partial dorsal series, HUJ EY606D; B, isolated scute, HUJ EY614; C, displaced dorsal scutes, holotype, HUJ EY603F. Abbreviations are as listed in Materials and Methods. Scale bars equal 1 cm. rays are segmented. This arrangement of the principal rays (10 + 9) is usual in the lower teleosts. No caudal scutes are observed. Scutes Two series of scutes are present, a predorsal (Fig. 10) and a ventral series. The predorsal scutes are situated anterior to the dorsal fin but they are poorly preserved in most of the specimens. About a dozen of them can be counted on specimen EY606D (Fig. 10A), but their number may be higher. The scutes are overlapping to form a straight series. Their exact shape remains unclear because of poor preservation. However, a smooth margin and a vermiculate ornamented surface were observed. The posterior-most scutes (Fig. 10B) are many times bigger than the anterior-most ones, as observed in Paraclupea and Ellimmichthys (Chang and Grande, 1997), Ezkutuberezi (Poyato-Ariza et al., 2000), and Triplomystus. They are ornamentated only near the anterodorsal margin. The posterior-most scute is hypertrophied and claw-shaped (Fig. 10C). A similar shape was described in Ezkutuberezi (Poyato-Ariza et al., 2000). The ventral series contains about scutes, this number varying according to the size of the specimens. It extends from the coracoids to near the anal fin, most likely to the anus. The lateral wings of the scutes are extremely elongated dorsoventrally, partly covering the underlying ribs. The particular shape to the ventral profile of Rhombichthys intoccabilis, gen. et sp. nov., is correlated with the extreme development of the ventral scutes in the middle of the series. In the smallest specimen, the ventral profile is much more rounded, as in Triplomystus, Ellimmichthys, or Ezkutuberezi (Chang and Grande, 1997:fig. 7; Poyato-Ariza et al., 2000:fig. 7). The correlation between the size of the specimen and the shape of the ventral profile will be discussed below. The anterior-most scutes present a sharp distal extremity, a condition found in other Ellimmichthyiformes. The shape of the posterior-most scutes is more singular, showing the sharp distal extremity and a well-developed spine, oriented posteriorly. This spine is bifid for the scutes situated near the middle of the series. The scute situated immediately ventral to the pelvic fin, called the subpelvic scute (Forey et al., 2003), is small with its dorsal extremity truncated beneath the pelvic fin. DISCUSSION Phylogenetic Relationships Rhombichthys intoccabilis, gen. et sp. nov., shares three of the six synapomorphies that define the Clupeomorpha division 2 (Grande, 1982, 1985): (1) the first hypural free and the second fused to the first ural centrum, (2) the presence of abdominal scutes, and (3) the development of dorsal scutes with a median keel. The three other synapomorphies of Clupeomorpha, (4) a well developed pre-epiotic fossa, (5) the supratemporal commissure canal primitively passing through parietals or through parietals and suppraoccipital, and (6) the otophysic connection that penetrates the exoccipital and forms ossified bullae in protic and usually also in the pterotic, are not clearly visible in any specimen, probably because of the preservation of the neurocranium. This character may only be observed in three-dimensional preserved fossils. Among Clupeomorpha, the Ellimmichthyiformes Grande, 1982, are defined by the presence of lateral expansion of dorsal scutes (Grande, 1982, 1985), found in Rhombichthys intoccabilis, gen. et sp. nov. The single family of this taxon, the Paraclupeidae, is characterized by the midline contact of the parietals, the presence of a beryciform foramen in the anterior ceratohyal, and the absence of the recessus lateralis (Chang and Grande, 1997).

10 66 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 1, 2010 Only the beryciform foramen is clearly seen in Rhombichthys intoccabilis, gen. et sp. nov. The subfamily Paraclupeinae was erected by Chang and Grande (1997) based on two characters: (1) the absence of pectinate or comblike teeth along the posterior edges of the dorsal scutes (considered as the primitive clupeomorph condition) and (2) posterior-most dorsal scutes being many times the size of the anterior-most dorsal scutes. Only character (2) is defined as synapomorphous. In Rhombichthys intoccabilis, gen. et sp. nov., the size of the last dorsal scutes is many times greater than that of the first dorsal scutes and the dorsal scutes, even if they are poorly preserved in all studied specimens, show the plesiomorphic condition of their posterior edges. Among ellimmichthyiforms, only some species of Diplomystus (Cavender, 1966:fig. 4; Poyato-Ariza et al., 2000:fig.9; Zaragüeta- Bagils, 2004), Ellimmichthys goodi (Zaragüeta-Bagils, 2004), Ellimmichthys longicostatus (Patterson and Rosen, 1977:fig. 37), Ellimmichthys maceioensis (Malabarba et al., 2004), Triplomystus noorae, T. oligoscutatus (Forey et al., 2003), Ezkutuberezi (Poyato-Ariza et al., 2000), and probably Scutatuspinosus do not possess a gap between the second and the third hypurals. The list is not exhaustive; Triplomystus applegatei shows a small hypural diastema even if the second and the third hypurals are in contact (Alvarado-Ortega and Ovalles-Damian, 2008:fig. 5). Note that Scutatuspinosus was described by Silva Santos and Correa (1985) as a member of the Clupeidae, in the new subfamily Scutatuspinosinae, but was considered to be closely related to the Paraclupeinae by Chang and Maisey (2003). The extreme dorsoventral elongation of the lateral expansion of the ventral scutes and the presence of posterior spines in the posterior-most ones is shared with Ellimma, Ellimmichthys, Ezkutuberezi, Paraclupea, Triplomystus, Tycheroichthys, and some species of Diplomystus, suchasd. birdi or D. dubertreti. However, only Rhombichthys intoccabilis, gen. et sp. nov. shows this posterior spine associated with a ventral spine. Sorbinichthys elusivo (Bannikov and Bacchia, 2000) shows a second dorsal fin ray that is very elongated, whereas in Rhombichthys intoccabilis, gen. et sp. nov., the fourth and the fifth dorsal fin rays are elongated, as in Diplomystus birdi. Rhombichthys intoccabilis, gen. et sp. nov., shows some features that are unique to this taxon. These include the anteroposterior extension of the dorsal fin, the elongation of some of the first dorsal fin rays, and the strikingly keen ventral profile, much more developed than in other Ellimmichthyiformes. The shape of the ventral scutes, the close contact of the second and the third hypurals, and the claw-shaped posterior-most dorsal scutes shared with Ezkutuberezi and Triplomystus suggest a close relationship of Rhombichthys, gen. nov., with these two taxa. Notes on Some Juvenile Characters Specimen EY603Z (Fig. 4) is the smallest of the studied specimens, being about 8.2 cm SL. Its ventral profile is rounded, as in Triplomystus, and its ventral scutes do not show the posteroventral spines present in larger specimens. However, it shows a long dorsal fin and a claw-shaped posterior dorsal scute. We interpret this specimen as a juvenile, and the absence of some characters a consequence of incomplete growth. It underlines that there are some characters that are only seen when the growth is in an advanced stage, such as the shape of the ventral scutes. Some other characters, such as the shape of the dorsal scutes or the anteroposterior extension of the dorsal fin, are present in early development. As noted by Forey et al. (2003) in Triplomystus and Poyato-Ariza et al. (2000) in Ezkutuberezi, the ratio between body depth and SL increaseswithsize. InRhombichthys intoccabilis, gen. et sp. nov., the depth of the holotype corresponds to 110% SL, whereas the depth of specimen EY603Z corresponds to only 67% SL. Our data suggest thus that growth of body depth is positively allometric. CONCLUSION Rhombichthys intoccabilis, gen. et sp. nov., is the first member of the Ellimmichthyiformes described from Ein Yabrud, Palestine. It is remarkable because of its unique shape, higher than long in adult specimens, and the extreme development of the keel-like ventral profile. The characters surveyed suggest a close relationship with others Paraclupeinae, especially with Triplomystus and Ezkutuberezi. A positively allometric growth of body depth is also suggested. New recent discoveries are changing our view on the geographic range and taxonomic diversity of ellimmichthyiforms and Mesozoic clupeomorphs in general. Future findings might challenge our understanding of their phylogenetic and biogeographical relationships. ACKNOWLEDGMENTS The authors thank M. Gayet for the availability and the preparation of the specimens; R. Rabinovitch (HUJ) for lending the specimens coming from Ein Yabrud; P. Loubry and C. Lemzaouda (UMR 5143, MNHN) for the photographs and their advice in the drawing; J. Maisey (AMNH), P. Forey (NMH), and D. Goujet and M. Véran (UMR 5143, MNHN) for their comments; P. Béarez (USM 0303, MNHN) for the lending of some extant specimens; F. de Lapparent de Broin (UMR 5143, MNHN) for her comments about the turtles of Ein Yabrud; and the two anonymous reviewers for their corrections. LITERATURE CITED Alvarado-Ortega, J., and E. Ovalles-Damián Triplomystus applegatei, sp. nov. (Teleostei: Ellimmichtyiformes). A rare triple armored herring from El Espinal quarry (Early Cretaceous), Chiapas, Southeastern Mexico. Journal of Vertebrate Paleontology 28: Bannikov, A. F., and F. Bacchia A remarkable clupeomorph fish (Pisces, Teleostei) from a new Upper Cretaceous marine locality in Lebanon. Senckenbergiana lethaea 80:3 11. Blainville, H. M. D. d Sur les ichthyolithes ou les poissons fossiles; pp in Nouveau Dictionnaire d Histoire Naturelle, Deterville, Paris. Cavender, T The caudal skeleton of the Cretaceous teleosts Xiphactinus Ichthyodectes and Gillicus, and its bearing on their relationship with Chirocentrus. Occasional papers of the Museum of Zoology, University of Michigan 650:1 15. Chalifa, Y Saurorhamphus judeaensis (Salmoniformes: Enchodontidae), a new longirostrine fish from the Cretaceous (Cenomanian) of Ein-Yabrud, near Jerusalem. Journal of Vertebrate Paleontology 5: Chalifa, Y. 1989a. Yabrudichthys and Serrilepis, two new genera of enchodontoids (Teleostei) from Lower Cenomanian beds of Ein Yabrūd, Israel. Israel Journal of Zoology 36: Chalifa, Y. 1989b. New species of Enchodus (Pisces: Enchodontoidei) from the Lower Cenomanian of Ein-Yabrud, Israel. Journal of Paleontology 63: Chalifa, Y. 1989c. Two new species of longirostrine fishes from the Early Cenomanian (Late Cretaceous) of Ein-Yabrud, Israel, with comments on the phylogeny of the Dercetidae. Journal of Vertebrate Paleontology 9: Chalifa, Y., and E. Tchernov Pachyamia latimaxillaris, new genus and species (Actinopterygii: Amiidae) from the Cenomanian of Jerusalem. Journal of Vertebrate Paleontology 2: Chang, M.-m., and C.-C. Chou On late Mesozoic fossil fishes from Zhejiang Province, China. Memoirs, Institute of Vertebrate Palaeontology and Palaeoanthropology. Academica Sinica 12:1 60. Chang, M.-m., and L. Grande Redescription of Paraclupea chetungensis, an early clupeomorph from the Lower Cretaceous of Southeastern China. Fieldiana: Geology 37:1 19. Chang, M.-m., and J. G. Maisey Redescription of Ellimma branneri and Diplomystus shengliensis, and relationships of some basal Clupeomorphs. American Museum Novitates 3404:1 35.

11 KHALLOUFI ET AL. A NEW DOUBLE-ARMORED ELLIMMICHTHYIFORM 67 Forey, P. L A three-dimensional skull of a primitive clupeomorph from the Cenomanian English Chalk, and implications for the evolution of the clupeomorph acusticolateralis system; pp in G. Arratia and A. Tintori (eds.), Mesozoic Fishes 3 Systematics, Paleoenvironment and Biodiversity. Verlag Dr. Friedrich Pfeil, München, Germany. Forey, P. L., L. Yi, C. Patterson, and C. E. Davis Fossil fishes from the Cenomanian (Upper Cretaceous) of Namoura, Lebanon. Journal of Systematic palaeontology 1: Frickhinger, K. A. (ed.) Fossilien Atlas Fische. Mergus, Verlag Für Natur, Melle, Germany, 1088 pp. Gaudant, M., and J. Gaudant Une nouvelle espèce de Diplomystus (Poisson téléostéen) dans le Crétacé supérieur du Sud tunisien. Bull. soc. géol. de France XIII(7): Gayet, M Recherches sur l ichthyofaune cénomanienne des Monts de Judée: les Acanthoptérygiens. Annales de Paléontologie (Vertébrés) 66: Gayet, M Considération sur la phylogénie et la paléobiogéographie des Ostariophysaires. Geobios, numéro spécial 6: Gayet, M Gonorhynchiforme nouveau du Cénomanien inférieur marin de Ramallah (Monts de Judée): Judeichthys haasi nov. gen. nov. sp. (Teleostei, Ostariophysi, Judeichtyidae nov. fam.). Bulletin du Muséum national d Histoire naturelle, Paris, 4e série, 7, section C, 1: Gayet, M Ramallichthys Gayet du Cénomanien inférieur marin de Ramallah (Judée), une introduction aux relations phylogénétiques des Ostariophysi. Mémoires du Museum national d Histoire naturelle, série C, sciences de la Terre 51:1 81. Grande, L A revision of the fossil genus Dipomystus with comments on the interrelationships of clupeomorph fishes. American Museum Novitates 2728:1 34. Grande, L Recent and extant clupeomorph fishes with materials for revision of the subgroups of Clupeoids. Bulletin of the American Museum of Natural History 181: Greenwood, P. H., D. E. Rosen, S. H. Weitzman, and G. S. Myers Phyletic studies of teleostean fishes with a provisional classification of living forms. Bulletin of the American Museum of Natural History 131: Haas, G A Cretaceous Pleurodire Turtle from the surroundings of Jerusalem. Israel Journal of Zoology 27: Haas, G On a new snakelike Reptile from the Lower Cenomanian of Ein Jabrud, near Jerusalem. Bulletin du Muséum national d Histoire naturelle, Paris, 4e série, 1, section C, 1: Heckel, J. J Die fossilen fische des Lebanon; pp in J. Russegger (ed.), Reisne in Europa. Asoen und Afrika mit besonderer Rucksicht auf die Naturwissenschaftlichen Verhaltnisse der betreffenden Lander, Stuttgart. Hay, M. J., S. L. Cumbaa, A. M. Murray, and A. G. Plint A new paraclupeid fish (Clupeomorpha, Ellimmichthyiformes) from a muddy marine pro-delta environment: middle Cenomanian Dunvegan Formation, Alberta, Canada. Canadian Journal of Earth Sciences 44: Malabarba, M. C., D. A. Do Carma, I. Gómex-Pérez, and J. V. de Queiroz-Neto A new clupeomorph fish from the Cretaceous Maceió Formation, Alagoas Basin, NE Brazil. Neues Jahrbuch für Geologie and Paläontologie Abhandlungen 233: Patterson, C., and D. E. Rosen Review of Ichthyodectiform and other Mesozoic teleosts fishes and the theory and practice of classifying fossils. Bulletin of the American Museum of Natural History 158: Polcyn, M. J., E. Tchernov, and L. L. Jacobs The Cretaceous biogeography of the Eastern Mediterranean with a description of a new basal Mosasauroid from Ein Yabrud, Israel; pp in Y. Tomida, T. H. Rich, and P. Vickers-Rich (eds.), Proceedings of the second Gondwanan dinosaur symposium. National Science Museum, Tokyo, July Poyato-Ariza, F. J., M. A. López-Horgue, and F. García-Garmilla A new early Cretaceous clupeomorph fish from the Arratia Valley, Basque Country, Spain. Cretaceous Research 21: Raab, M., and Y. Chalifa A new enchodontid fish from the Upper Cenomanian of Jerusalem, Israel. Palaeontology 30: Rieppel, O., H. Zaher, E. Tchernov, and M. J. Polcyn The anatomy and relationships of Haasiophis terrasanctus, a fossil snake with welldeveloped hind limbs from the Mid-Cretaceous of the Middle East. Journal of Paleontology 77: Signeux, J Notes paléoichthyologiques. V. Diplomystus Dubertreti, une nouvelle espèce du Sénonien du Liban. Bulletin du Muséum national d Histoire naturelle, Paris, 2e série, t. 23, 6: Silva Santos, R. d., and V. L. d. Silva Corréa Contribuiçaoaoconhecimento da paleoictiofaunula do Cretaceo no Brasil. Coletânea de trabalhos paleontologicos in Seçao paleontologia e estratigrafa, série geologia 27: Steindachner, F Ichthyologische Beiträge. [I.]. Sitzungsberg. Akad. Wiss. Wien 69: Taverne, L Tselfatia formosa, téléostéenmarinducrétacé(pisces, Actinopterygii) et la position systématique des Tselfatiiformes ou Bananogmiiformes. Geodiversitas 22:5 22. Tchernov, E., O. Rieppel, H. Zaher, M. J. Polcyn, and L. L. Jacobs A fossil snake with limbs. Science 287: Toombs, H. A., and A. E. Rixon The use of plastics in the transfer method of preparing fossils. Museum s Journal 50: Valenciennes, A Histoire naturelle des poissons, Volume 20. P. Bertrand, Paris, 472 pp. Woodward, A. S Catalogue of the Fossil Fishes in the British Museum (Natural History), Volume 4, containing the Actinopterygian Teleostemi of the Suborders Isospondyli (in part), Ostariophysii, Apodes, Percesoces, Hemibranchii, Acanthopterygii and Anacanthini. British Museum, London, 636 pp. Zaragüeta-Bagils, R Basal clupeomorphs and ellimmichtyiform phylogeny; pp in G. Arratia and A. Tintori (eds.), Mesozoic Fishes 3 Systematics, Paleoenvironment and Biodiversity. Verlag Dr. Friedrich Pfeil, München, Germany. Received March 15, 2008; accepted March 26, 2009.