sign in sign up
<<
Home , Acrodus, Acronemus, Capitanian, Enchodus, Hybodontiformes, Lopingian

Palaeontologia Electronica palaeo-electronica.org

The oldest record of gnathostome from Greece: from the of Hydra Island

Thodoris Argyriou, Carlo Romano, Jorge D. Carrillo-Briceño, Morgane Brosse, and Richard Hofmann

ABSTRACT

The deposits of Hydra Island, Greece, have been known for over a cen- tury and host some of the best-studied and most diverse invertebrate assemblages of the ancient Paleotethys Ocean. However, until now, no fossils of jawed ver- tebrates had been reported from Greece. Recent fieldwork on Hydra Island brought to light rare cartilaginous remains, including a tooth belonging to an unknown hybodontiform , as well as an unidentifiable dermal denticle of an euselachian shark. Despite similarities with iconic Paleozoic and durophagous eusela- chians, the Hydriot tooth likely corresponds to a new , but is provisionally left in open nomenclature until more material becomes available. The new chondrichthyan fossils from Hydra Island correspond to one of the few Lopingian (late Permian) occur- rences known from the Paleotethys. Moreover, they constitute the oldest record of jawed-vertebrate fossils from Greece, predating younger occurrences by more than 50 million .

Thodoris Argyriou. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. [email protected] Carlo Romano. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. [email protected] Jorge D. Carrillo-Briceño. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. [email protected] Morgane Brosse. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. [email protected] Richard Hofmann. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland; Leibniz Institut für Evolutions und Biodiversitätsforschung, Museum für Naturkunde, Invalidenstraße 43, Berlin, 10115, Germany. [email protected]

Keywords: late Permian; Paleotethys; fish; ; Hydra Island; Greece

Submission: 6 October 2016 Acceptance: 27 February 2017

Argyriou, Thodoris, Romano, Carlo, Carrillo-Briceño, Jorge D., Brosse, Morgane, and Hofmann, Richard. 2017. The oldest record of gnathostome fossils from Greece: Chondrichthyes from the Lopingian of Hydra Island. Palaeontologia Electronica 20.1.8A: 1-9 palaeo-electronica.org/content/2017/1769-permian-sharks-of-greece

Copyright: © March 2017 Society of Vertebrate Paleontology. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. creativecommons.org/licenses/by/4.0/ ARGYRIOU ET AL.: PERMIAN OF GREECE

INTRODUCTION one dermal denticle, deriving from the same hand- sample. These fossils represent the oldest, unam- The Permian Period (~298–252 Ma) was a biguous gnathostome occurrences of Greece, pre- particularly important time interval for life on the dating younger occurrences by more than 50 planet, characterized by a of global-scale million years. Furthermore, this occurrence is a environmental disturbances that climaxed at ~252 valuable addition to the poor Lopingian (late Perm- Ma with the most-severe end-Permian mass ian) chondrichthyan record of the Paleotethys event (Benton and Twitchett, 2003; Bur- (Schaumberg, 1977; Ginter et al., 2010; Koot, gess et al., 2014). Despite the catastrophic impact 2013). of this mass extinction event for most groups (e.g., Benton and Twitchett, 2003), many osteichthyan GEOLOGICAL SETTING AND AGE clades as well as euselachians were less severely affected (Friedman and Sallan, 2012; Koot, 2013; Hydra Island is located in the northwestern Romano et al., 2016). Recent works have margin of Myrtoon Basin, western Aegean Sea improved our understanding of the Permian chon- (Eastern Mediterranean), ~70 km to the south- drichthyan fossil record (Ginter et al., 2010; Hampe southwest of Athens (Figure 1.1). The late Paleo- et al., 2013; Hodnett et al., 2013; Ivanov et al., zoic outcrops, first reported by Renz (1910), are 2013; Koot, 2013; Koot et al., 2013; Chahud and located along the southeastern coast of the island Petri, 2014; Ivanov and Lebedev, 2014; Ivanov et and comprise shallow water carbonate and silici- al., 2015), but the latter remains sporadic and less clastic successions (Figure 1.2-3), which were well known in comparison to that of the deposited on the northwestern Paleotethyan mar- (Hampe et al., 2013; Koot, 2013; Koot et al., 2013 gin, forming the base of the “sub-Pelagonian” zone and references therein). This fact might bias inter- (Baud et al., 1990; Grant et al., 1991). A diverse pretations about the timing of clade origins, impact array of fossils is known from the autochthonous of the end-Permian mass extinction on chondrich- Permian sedimentary successions of Hydra, thyans and the hypothesized patterns of the Early including algae (Jenny et al., 2004), benthic fora- Triassic biotic recovery. minifera (Vachard et al., 1995; Jenny et al., 2004; The restricted occurrences of Paleozoic (Silu- Vachard et al., 2008), ostracods (Crasquin-Soleau rian–Permian) sedimentary rocks in Greece have and Baud, 1998; Kornicker and Sohn, 2000) and attracted considerable scientific attention since brachiopods (Grant, 1972, 1995; Shen and their first discovery, more than a century ago Clapham, 2009). are mostly known (Renz, 1910). Several invertebrate assemblages from the upper part of the Lopingian have been described from exotic or autochthonous (Nestell and Wardlaw, 1987), where the successive rocks, but until now conodonts were the only puta- occurrences of Neogondolella leveni and Neogon- tive vertebrates reported (e.g., Nestell and Ward- dolella orientalis indicate a (early law, 1987; Groves et al., 2003; for more information Lopingian) age (Kozur, 1975). The matrix sur- on the ongoing discussion about affinities rounding the chondrichthyan fossils contained see Donoghue et al., 2000; Turner et al., 2010; three conodont P1 elements, belonging to Hindeo- Murdock et al., 2013). Reif (1978) mentioned the dus. The best-preserved one is assignable to Hin- presence of “hybodontid-type” dermal denticles in deodus typicalis, which has a Lopingian–lower the Permian of Greece, but did not describe or fig- stratigraphic range. Since Induan (earliest ure any, nor did he provide any locality or reposi- Triassic) deposits are unknown from Hydra, our tory information. Previous oldest ascertained conodonts best indicate a Lopingian age for the gnathostome occurrences from the country include studied sample. poorly preserved actinopterygian remains from the Lower of Lefkada Island, Ionian Sea MATERIAL AND METHODS (Kottek, 1964). These are succeeded by Maas- trichtian– chondrichthyan and teleostean The chondrichthyan tooth was partly exposed fossils from various localities around the country on the surface of a hand-sample (~1.5 kg) of silici- (Koch and Nikolaus, 1969; Trikolas, 2008; Cavin et fied dark grey-colored limestone. The sample was al., 2012). dissolved in a 10% buffered acetic acid (Jeppsson Recent fieldwork on Hydra Island by R.H. and et al., 1999) and concentrated by heavy liquid sep- colleagues has brought to light new invertebrate aration (Jeppsson and Anehus, 1999). The residue and vertebrate material. The latter, described in was handpicked under a binocular microscope, this work, comprises one chondrichthyan tooth and and the recovered vertebrate material was imaged

2 PALAEO-ELECTRONICA.ORG

FIGURE 1. Geographical and geological context of the Hydriot chondrichthyan fossils. 1, Map of Greece showing the location of Hydra Island; 2, Outcrop map of Hydra Island showing the location of the sampled section “EP” south of the village of Episkopi. Outcrop map after Grant et al. (1991); 3, Stratigraphic section of the Episkopi Formation show- ing the provenance (“EP-Z”) of the examined gnathostome fossils. with a JSM-6010PLUS LA Scanning Electron SYSTEMATIC PALEONTOLOGY Microscope at the Center for Microscopy and Class CHONDRICHTHYES Huxley, 1880 Image Analysis, University of Zurich (ZMBUZH). Cohort Hay, 1902 Both gnathostome specimens are catalogued and Order HYBODONTIFORMES Maisey, 1975 housed in the vertebrate collection of the Museum Hybodontiformes Gen. et sp. indet. of Paleontology and Geology, National and Kapo- Figure 2.1-5 distrian University of Athens, Greece (AMPG). Tooth and dermal denticle terminology applied Material. One tooth of indeterminate jaw position, herein adheres to that of previous works (Reif, AMPG 550. 1978; Ginter et al., 2010; Cappetta, 2012). For Description. The crushing-type tooth is character- comparative purposes we examined hybodontiform ized by a well-preserved crown and a somewhat and material from the damaged root. The isolated nature of the tooth of Monte San Giorgio (Ticino, Switzerland), housed allows only a tentative attribution of one of the two at the Paleontological Institute and Museum, Uni- broad lateral surfaces to labial, based on the com- versity of Zurich, Switzerland (PIMUZ). For a com- bination of a well-defined root sulcus accommodat- plete list of specimens catalogued at the PIMUZ ing a single row of foramina, as well as the lingual the reader is referred to Rieppel (1981, 1982) and inclination of the underlying root surface. Mutter (1998a, 1998b). The crown bears a single, low and rounded main cusp. In occlusal view (Figure 2.1) the crown

3 ARGYRIOU ET AL.: PERMIAN SHARKS OF GREECE

FIGURE 2. Chondrichthyan material from Hydra. 1-5, Hybodontiformes indet. tooth (AMPG 550) in occlusal (1), basal (2), presumed lingual (3), profile (4), and presumed labial (5) views. Scale bar equals 5 mm. 6, Euselachii indet. der- mal denticle (AMPG 551) in anterolateral view. Scale bar equals 100 μm.

4 PALAEO-ELECTRONICA.ORG

is triangular with truncated mesial and distal edges. inclusive groups, due to their generalized and/or It overhangs the root almost completely and forms often homoplasic morphologies (Ginter et al., 2010; a distinct presumably lingual projection. The crown Cappetta, 2012). Despite this fact, a review of den- bears a distinct labiolingual crest and a less distinct tal anatomy of Paleozoic–early Mesozoic forms mesiodistal crest, the two meeting at an almost can provide some information about the systematic right angle, on the apex of the main cusp. The affinities of the Hydriot tooth. mesiodistal crest fades before reaching the edges Macroscopic teeth of Paleozoic–early Meso- of the crown. Most delicate secondary, crests radi- zoic stem neoselachians exhibit crowns with well- ate from the junction point of the two primary defined median cusps and, when present, acces- crests, while few originate from the labiolingual and sory cusplets and/or a median cutting edge (Ginter mesiodistal crests, near their junction. Few sec- et al., 2010; Koot et al., 2013). Their roots are ondary crests run continuously until the base of the either hemiaulacorhize or pseudo-polyaulacorhize; crown where they might bifurcate. Others fade mid- they typically bear fewer, enlarged foramina (the way to reappear near the base of the crown. When median ones in particular) than other euselachians; viewed lingually or labially, the crown is boomer- and are somewhat arcuate in basal view, due to ang-shaped. The lingual surface is convex (Figure the presence of a lingual protuberance (Ginter et 2.3), bearing a well-developed, median, lateroba- al., 2010). None of the above is seen in the exam- sally directed protuberance. The presumed con- ined specimen, rendering a neoselachian attribu- cave labial surface bears fewer secondary crests tion unfavorable. Low-crowned crushing teeth and is characterized by a socket-like elliptical hol- without lateral cusplets, but with anaulacorhize, low (Figure 2.5), presumably for accommodating multiforaminate roots, which often include a labial the lingual protuberance of the neighboring tooth of sulcus accommodating a single row of specialized the same file, indicating some weak imbrication of foramina, are seen in members of the Hybodon- the dentition. tiformes (e.g., ; ; Omanoselache; The anaulacorhize root is apicobasally, Onychoselache) as well as in the stem euselachian mesiodistally, and labiolingually shorter than the (sensu Maisey, 2011) Acronemus (Johnson, 1981; crown and conforms to its contour. In lingual view Rieppel, 1982; Ginter et al., 2010; Cappetta, 2012; (Figure 2.3), the root is damaged, but is populated Koot et al., 2013, 2015). by randomly arranged, apicobasally elongate Hybodontiformes can exhibit very disparate foramina. In labial view (Figure 2.5), the root is dental features, and are formally united as a group markedly shallow, less than one fourth of the crown by means of cranial and postcranial anatomy height. The labial face of root bears a weak sulcus (Maisey, 1975, 1982; Ginter et al., 2010; Cappetta, along the crown-root margin, populated by a single 2012). Within the Paleozoic–Triassic Hybodon- row of well-arranged, apicobasally elongate foram- tiformes, dental anatomy somewhat comparable to ina, smaller and more numerous (~20) than those that of our specimen occurs in Acrodus, Lissodus, of the other lateral face. The basal half of the root Hamiltonichthys, and Onychoselache (e.g., Ginter is slanted lingually, bearing larger, sparsely et al., 2010; Cappetta, 2012). Despite the uncertain arranged, enlarged foramina. The base of the root, affinities of Acronemus within euselachians, its although damaged, appears flat and sub-rectangu- tooth morphology is hybodontiform-like (Rieppel, lar, without a distinct lingual protuberance. In pro- 1982; Maisey, 2011; Cappetta, 2012), and resem- file view (Figure 2.4), the crown clearly overhangs blant to that of AMPG 550. One of the most con- the root. spicuous differences among the abovementioned Remarks. Several Paleozoic and Mesozoic chon- genera is the occurrence of a lingual crown protu- drichthyans have convergently evolved low berance in Hamiltonichthys (Maisey, 1989), Ony- crowned, crushing-type teeth. However, the pres- choselache (Coates and Gess, 2007) and ence of a single cusp, the ridged crown ornamenta- Acronemus (Rieppel, 1982), rather than a labial tion and the anaulacorhize root anatomy, which one as in most other Hybodontiformes. includes a distinct sulcus with specialized foramina The single, blunt main cusp and the ridged along the crown–root boundary, compare favorably ornamentation are common features of Acrodonti- to features seen in durophagous euselachians dae (sensu Cappetta, 2012). Acrodus (s.l.) is the (e.g., Ginter et al., 2010; Cappetta, 2012). Isolated only member of the family that shows resem- teeth of Paleozoic and early Mesozoic stem euse- blances to our specimen and has Paleozoic occur- lachians, hybodontiforms and stem neoselachians rences (as ?Acrodus) (Johnson, 1981; Hodnett et are often difficult to distinguish and attribute to less al., 2011; Hampe et al., 2013). It is otherwise prom-

5 ARGYRIOU ET AL.: PERMIAN SHARKS OF GREECE

inently known from Triassic (e.g., Rieppel, 1981; A close relationship between AMPG 550 and Mutter, 1998a, 1998b; Cappetta, 2012) and the Triassic or Homalodontus (= younger Mesozoic deposits (Cappetta, 2012). “Wapitiodus”), both possessing flat-crowned teeth, Acrodus teeth exhibit marked monognathic hetero- is excluded based on the general tooth morphology donty, with symphyseal, parasymphyseal and pos- and ornamentation (Mutter et al., 2007, 2008; terior teeth being mesiodistally narrower and more Romano and Brinkmann, 2010). The potential apicobasally arcuate than lateral teeth (Mutter, Permian stem euselachian possess a 1998a; Ginter et al., 2010; Cappetta, 2012), resem- smooth crown, markedly dissimilar to that of the bling the Hydriot tooth. However, Acrodus teeth Hydriot specimen (Haubold and Schaumberg, bear a distinct mesiodistal crest and a less distinct 1985; Hampe in Cappetta, 2012). Finally, the uni- or absent labiolingual crest (Johnson, 1981; cuspidate teeth of the hybodontiform Omanose- Rieppel, 1981; Mutter, 1998a, 1998b; Ginter et al., lache differ in ornamentation, shape, and direction 2010; Hodnett et al., 2011; Cappetta, 2012; Hampe of crown protuberance and exhibit fewer but larger et al., 2013). In addition, secondary crests initiate root foramina (Koot et al., 2013, 2015). all along the horizontal crest, are tightly packed In summary, AMPG 550 shows moderate to and exhibit strong bifurcation patterns, whereas a strong morphological affinities with Hamiltonich- socket for tooth interlocking is absent in most spe- thys, Acronemus and moderate affinities with cies (Johnson, 1981; Rieppel, 1981; Mutter, 1998a, Paleozoic ?Acrodus teeth of Johnson (1981). How- 1998b; Ginter et al., 2010; Hodnett et al., 2011; ever, conspicuous differences in crown shape and Cappetta, 2012; Hampe et al., 2013), except in A. ornamentation, interlocking process and root georgii, where it is situated lingually (Mutter, development preclude its assignment to any of the 1998b). The abovementioned differences preclude aforementioned genera. Our small sample size the inclusion of the Hydra chondrichthyan in Acro- does not permit the erection of a new and, dus. on the basis of dental characteristics alone, we Teeth of the genus Hamilton- prefer to leave it in open nomenclature within ichthys resemble the Hydriot tooth in terms of Hybodontiformes until additional fossil material occlusal crown ornamentation, while they also bear becomes available. a lingual protuberance and a labial scar (Maisey, Cohort EUSELACHII Hay, 1902 1989). Our specimen differs from Hamiltonichthys Euselachii indet. in exhibiting more rounded corners at the mesial Figure 2.6 and distal end of the crown in occlusal view. Ony- choselache (Coates and Gess, 2007) exhibits teeth Material. One fragmented dermal denticle, AMPG of more subtle crown ornamentation and higher 551. roots than AMPG 550. Finally, unicuspidate Lisso- Description. The relatively well-preserved crown dus teeth have strongly lingually bent roots, is lanceolate and curved posteriorly. It possesses a whereas mesiodistal and labiolingual occlusal well-developed, tricuspid distal crown, a neck and crests form more pronounced, sharp, and often a base. Three keels can be seen on the anterodis- jagged, cutting edges (Rees and Underwood, tal part of the crown. The median keel bears a shal- 2002; Duncan, 2004; Ginter et al., 2010). The low groove along its basal half and is distinctly marked labiolingual crest on the crown of AMPG higher than the two lateral keels. Its proximal end 550, the lingual bulbous crown projection, along continues as a gentle ridge on the anterior surface with the wider spacing between the secondary of the neck. The lateral keels are grooved along ridges are also reminiscent of characteristics of their length and splay dorsolaterally, in anterior medial teeth of the ?Pennsylvanian–Middle Trias- view. The neck is slightly narrower than the crown. sic Acronemus (Euselachii incertae sedis) The base is poorly preserved, but must have had a (Rieppel, 1982; Rees and Underwood, 2002; triangular outline and is wider than the crown, in Maisey, 2011). Despite the presence of a distinct proximal view. lingual protuberance, Acronemus teeth do not pos- Remarks. The presence of a slender crown with sess a labial socket, differing in that regard from three keels on its anterior surface and a narrow the Hydriot tooth. Acronemus teeth are further dif- neck are common features in scales of Paleozoic– ferentiated by their height and their shorter, Mesozoic ctenacanthids, but are also common in strongly saddle-shaped crown (Rieppel, 1982). euselachian chondrichthyans (Reif, 1978; Hansen, Unfortunately, little is known about root vascular- 1986; Rieppel et al., 1996; Johns et al., 1997; ization in Acronemus teeth. Derycke-Khatir et al., 2005; Ivanov et al., 2013). The Hydriot denticle compares favorably to the par-

6 PALAEO-ELECTRONICA.ORG

agenus Moreyella (Gunnell, 1933; Hansen, 1986), Electronica for their insightful comments that which has been tentatively affiliated with Carbonif- improved the quality of this manuscript. Special erous–Permian hybodontiform chondrichthyans thanks to M. Kirschmann (ZMBUZH) for assisting (e.g., Derycke-Khatir et al., 2005). The Triassic the SEM imaging process; R. Kindlimann (Switzer- paragenera Fragilicorona and Labascicorona and) for providing useful comments during the (Johns et al., 1997) also display very similar, tricus- early stages of the work and M. Leu (PIMUZ) for pid distal crowns like the denticle in question, but helping with acid preparation of hand samples. We their systematic affinities beyond the euselachian are indebted to M.R. Sánchez-Villagra and M. level have not been discussed (Ivanov et al., Hautmann (both PIMUZ) for their support during 2013). Hybodontiform dermal denticles can exhibit the preparation of this study. M. Haas (ETH, disparous morphologies, even in the same individ- Zürich) is thanked for field assistance and S. Rous- ual, ranging from somewhat stockier and shorter siakis (AMPG) for providing specimen numbers. types with more keels and stout or undeveloped Access to the field localities and sampling permis- necks (Reif, 1978), to more delicate and elongate sion was provided by the Hellenic Ministry of Cul- ones like AMPG 551. Denticles of the latter type ture and Sports, and the AMPG. cannot be effectively distinguished from those of other euselachians (Rieppel et al., 1996; Ivanov et REFERENCES al., 2013). Thus, it is unclear whether the Hydra Baud, A., Jenny, C., Papanikolaou, D., Sideris, C., and denticle comes from the same genus or individual Stampfli, G. 1990. New observations on Permian as the tooth AMPG 550. stratigraphy in Greece and geodynamic interpreta- tion. Bulletin of the Geological Society of Greece, CONCLUSION 25(1):187-206. Benton, M.J. and Twitchett, R.J. 2003. How to kill The new chondrichthyan material from the (almost) all life: the end-Permian extinction event. Wuchiapingian (Early Lopingian) of Hydra Island Trends in Ecology & Evolution, 18(7):358-365. represents the oldest gnathostome remains of Burgess, S.D., Bowring, S., and Shen, S.-Z. 2014. High- Greece, and adds a new occurrence to the rela- precision timeline for Earth’s most severe extinction. tively poor late Permian fish fossil record (Koot, Proceedings of the National Academy of Sciences, 2013; Romano et al., 2016). Coeval occurrences 111(9):3316-3321. from the western Paleotethys are mainly known Cappetta, H. 2012. Chondrichthyes II: Mesozoic and from Western and Central (Koot, 2013). , p. 512. In Schultze, H.P. The presence of bed-controlled chondrichthyan (ed.), Handbook of Paleoichthyology, vol. 3B. Dr. microremains associated with conodont index fos- Friedrich Pfeil, München. sils emphasizes the importance of the new locality Cavin, L., Alexopoulos, A., and Piuz, A. 2012. Late Cre- taceous () ray-finned from the and future fieldwork on Hydra could further island of Gavdos, southern Greece, with comments improve our knowledge about chondrichthyan fau- on the evolutionary history of the aulopiform teleost nas a few million years before the largest mass Enchodus. Bulletin de la Société Géologique de extinction event. The Hydriot tooth presented France, 183(6):561-572. herein shows particular resemblances to iconic Chahud, A. and Petri, S. 2014. New chondrichthyans Paleozoic (Hamiltonichthys) and Paleozoic–Meso- from the (Early Permian, Paraná zoic taxa (Acrodus, Acronemus), but likely belongs Basin), Brazil: origin, paleoenvironmental and paleo- to a new genus and species that could prove geographical considerations. Proceedings of the important for the resolution of hybodontiform and Geologists' Association, 125(4):437-445. euselachian phylogeny. However, additional fossil Coates, M.I. and Gess, R.W. 2007. A new reconstruction material is required for a more conclusive system- of Onychoselache traquairi, comments on early chondrichthyan pectoral girdles and hybodontiform atic interpretation. The discovery of Permian chon- phylogeny. Palaeontology, 50(6):1421-1446. drichthyans in Hydra highlights the need for Crasquin-Soleau, S. and Baud, A. 1998. New Permian additional paleontological survey in the pre-Ceno- ostracods from Greece (Hydra Island). Journal of zoic, and especially the Paleozoic, deposits of Micropalaeontology, 17(2):131-152. Greece. Derycke-Khatir, C., Vachard, D., Dégardin, J.-M., Flores de Dios, A., Buitrón, B., and Hansen, M. 2005. Late ACKNOWLEDGMENTS Pennsylvanian and Early Permian chondrichthyan microremains from San Salvador Patlanoaya The authors wish to thank the two anonymous (Puebla, ). Geobios, 38(1):43-55. reviewers and the editorial team of Palaeontologia

7 ARGYRIOU ET AL.: PERMIAN SHARKS OF GREECE

Donoghue, P.C.J., Forey, P.L., and Aldridge, R.J. 2000. and Science, Bulletin. New Mexico Museum of Natu- Conodont affinity and phylogeny. Biological ral History, Albuquerque. Reviews, 75(2):191-251. Huxley, T.H. 1880. On the application of the laws of evo- Duncan, M. 2004. Chondrichthyan genus Lissodus from lution to the arrangement of the Vertebrata, and more the Lower of . Acta Palaeonto- particularly of the Mammalia. Proceedings of the Sci- logica Polonica, 49(3):417-428. entific Meetings of the Zoological Society of London, Friedman, M. and Sallan, L.C. 2012. Five hundred mil- 1880:649–662. lion years of extinction and recovery: a Ivanov, A.O. and Lebedev, O.A. 2014. Permian chon- survey of large-scale diversity patterns in fishes. drichthyans of the Kanin Peninsula, Russia. Paleon- Palaeontology, 55(4):707-742. tological Journal, 48(9):1030-1043. Ginter, M., Hampe, O., and Duffin, C. 2010. Chondrich- Ivanov, A.O., Nestell, G.P., and Nestell, M.K. 2013. Fish thyes. Paleozoic Elasmobranchii: Teeth. Handbook assemblage from the (Middle Permian) of of Paleoichthyology, 3D. Dr. Friedrich Pfeil, the Apache Mountains, West , USA, p. 152- München. 160. In Lucas, S.G., DiMichele, W.A., Barrick, J.E., Grant, R.E. 1972. The Lophophore and Feeding Mecha- Schneider, J.W., and Spielmann, J.A. (eds.), The nism of the Productidina (Brachiopoda). Journal of Carboniferous-Permian transition. New Mexico Paleontology, 46(2):213-248. Museum of Natural History & Science, Albuquerque, Grant, R.E. 1995. Upper Permian brachiopods of the New Mexico, USA. superfamily Orthotetoidea from Hydra Island, Ivanov, A.O., Nestell, M.K., and Nestell, G.P. 2015. Mid- Greece. Journal of Paleontology, 69(04):655-670. dle Permian fish microremains from the early Capita- Grant, R.E., Nestell, M.K., Baud, A., and Jenny, C. 1991. nian of the ,West Texas, USA. Permian stratigraphy of Hydra Island, Greece. Micropaleontology, 61:301-312. Palaios, 6(5):479-497. Jenny, C., Izart, A., Baud, A., and Jenny, J. 2004. Le Per- Groves, J.R., Larghi, C., Nicora, A., and Rettori, R. 2003. mien de l'île d'Hydra (Grèce), micropaléontologie, (Lower Carboniferous) microfossils sédimentologie et paléoenvironnements. Revue de from the Chios Mélange (Chios Island, Greece). Paléobiologie, 23(1):275-312. Geobios, 36(4):379-389. Jeppsson, L. and Anehus, R. 1999. A new technique to Gunnell, F.H. 1933. Conodonts and fish remains from the separate conodont elements from heavier minerals. Cherokee, City, and Wabaunsee Groups of Alcheringa: An Australasian Journal of Palaeontol- Missouri and Kansas. Journal of Paleontology, ogy, 23(1):57-62. 7(3):261-297. Jeppsson, L., Anehus, R., and Fredholm, D. 1999. The Hampe, O., Hairapetian, V., Dorka, M., Witzman, F., Optimal Acetate Buffered Acetic Acid Technique for Akbari, A.M., and Korn, D. 2013. A first Late Permian Extracting Phosphatic Fossils. Journal of Paleontol- fish fauna from Baghuk Mountain (Neo-Tethyan ogy, 73(5):964-972. shelf, central Iran). Bulletin of Geosciences, 88(1):1- Johns, M.J., Barnes, C.R., and Orchard, M.J. 1997. Tax- 20. onomy and Biostratigraphy of the Middle and Late Hansen, M.C. 1986. Microscopic chondrichthyan Triassic elasmobranch ichthyoliths from Northeastern remains from Pennsylvanian marine rocks of Ohio British Columbia Canadian government publishing, and adjacent areas, Unpublished PhD Thesis, The Ottawa, Ontario, Canada. Ohio State University, Columbus, Ohio, USA. Johnson, G.D. 1981. Hybodontoidei (Chondrichthyes) Haubold, H. and Schaumberg, G. 1985. Die Fossilien from the Wichita-Albany Group (Early Permian) of des Kupferschiefers. A. Ziemsen, Wittenberg Luther- Texas. Journal of Vertebrate Paleontology, 1(1):1-41. stadt. Koch, K.E. and Nikolaus, H.J. 1969. Zur Geologie des Hay, O.P. 1902. Bibliography and catalogue of fossil Ver- Ostpindos – Flyschbeckens und seiner Umrandung, tebrata of . Bulletin of the United Institute for Geology and Subsurface Research, Ath- States Geological Survey, 179:1-868. ens. Hodnett, J.-P., Elliott, D.K., and Olsen, T. 2011. The Koot, M.B. 2013. Effects of the late Permian mass hybodontiform sharks (Chondrichthyes) from the extinction on chondrichthyan palaeobiodiversity and marine Permian (Leonardian) Kaibab Formation of distribution patterns, Unpublished PhD Thesis, Plym- northern Arizona. Ichthyolith Issues, Special Publica- outh University, Plymouth, UK. Available at https:// tion, 12:23-24. pearl.plymouth.ac.uk/handle/10026.1/1584. Hodnett, J.-P., Elliott, D.K., and Olson, T.J. 2013. A new Koot, M.B., Cuny, G., Orchard, M.J., Richoz, S., Hart, basal hybodont (Chondrichthyes, Hybodontiformes) M.B., and Twitchett, R.J. 2015. New hybodontiform from the middle Permian () Kaibab Forma- and neoselachian sharks from the Lower Triassic of tion, of Northern Arizona, p. 103-108. In Lucas, S.G., Oman. Journal of Systematic Palaeontology, DiMichele, W.A., Barrick, J.E., Schneider, J.W., and 13(10):891-917. Spielmann, J.A. (eds.), The Carboniferous-Permian Koot, M.B., Cuny, G., Tintori, A., and Twitchett, R.J. Transition. New Mexico Museum of Natural History 2013. A new diverse shark fauna from the (Middle Permian) Khuff Formation in the interior

8 PALAEO-ELECTRONICA.ORG

Haushi-Huqf area, Sultanate of Oman. Palaeontol- toidea (Selachii). Journal of Vertebrate Paleontology, ogy, 56(2):303-343. 22(3):471-479. Kornicker, L.S. and Sohn, I.G. 2000. Myodocopid Reif, W.-E. 1978. Types of morphogenesis of the dermal Ostracoda from the late Permian of Greece and a skeleton in fossil sharks. Paläontologische basic classification for Paleozoic and Mesozoic Myo- Zeitschrift, 52(1):110-128. docopida. Smithsonian Contributions to Paleobiol- Renz, C. 1910. Stratigraphische Untersuchungen im ogy, 91:1-33. griechischen Mesozoikum und Paläozoikum. Jahr- Kottek, A. 1964. Fischreste aus dem griechischen Lias. buch der Kaiserlich Königlichen Geologischen Reich- Annales géologiques de pays hélleniques, sanstalt, 60(3):57-87. 39:175‐181+1 tab. Rieppel, O. 1981. The hybodontiform sharks from the Kozur, H. 1975. Beiträge zur Conodontenfauna des Middle Triassic of Mte. San Giorgio, Switzerland. Perm. Geologisch-Paläontologische Mitteilungen Neues Jahrbuch für Geologie und Paläontologie - Innsbruck, 5(4):1-44+4pls. Abhandlungen, 161(3):324-353. Maisey, J.G. 1975. The interrelationships of phalacan- Rieppel, O. 1982. A new genus of shark from the Middle thus selachians. Neues Jahrbuch für Geologie und Triassic of Monte San Giorgio, Switzerland. Palaeon- Paläontologie - Abhandlungen, 9:553-565. tology, 25(2):399-412. Maisey, J.G. 1982. The anatomy and interrelationships of Rieppel, O., Kindliman, R., and Bucher, H. 1996. A new Mesozoic hybodont sharks. American Museum Novi- fossil fish fauna from the Middle Triassic () of tates, 2724:1-48. North-Western Nevada, p. 501-512. In Arratia, G. and Maisey, J.G. 1989. Hamiltonichthys mapesi, g. & sp. nov. Viohl, G. (eds.), Mesozoic Fishes - Systematics and (Chondrichthyes; Elasmobranchii), from the Upper Paleoecology. Dr. Friedrich Pfeil, München, Ger- Pennsylvanian of Kansas. American Museum Novi- many. tates, 2931:1-42. Romano, C. and Brinkmann, W. 2010. A new specimen Maisey, J.G. 2011. The braincase of the Middle Triassic of the hybodont shark Palaeobates polaris with three- shark Acronemus tuberculatus (Bassani, 1886). dimensionally preserved Meckel's cartilage from the Palaeontology, 54(2):417-428. Smithian () of Spitsbergen. Journal of Murdock, D.J.E., Dong, X.-P., Repetski, J.E., Marone, F., Vertebrate Paleontology, 30(6):1673-1683. Stampanoni, M., and Donoghue, P.C.J. 2013. The Romano, C., Koot, M.B., Kogan, I., Brayard, A., Minikh, origin of conodonts and of vertebrate mineralized A.V., Brinkmann, W., Bucher, H., and Kriwet, J. 2016. skeletons. Nature, 502(7472):546-549. Permian–Triassic Osteichthyes (bony fishes): diver- Mutter, R.J. 1998a. Tooth variability and reconstruction sity dynamics and body size evolution. Biological of dentition in Acrodus sp. (Chondrichthyes, Selachii, Reviews, 91(1):106-147. Hybodontoidea) from the Grenzbitumenzone (Middle Schaumberg, E. 1977. Der Richelsdorfer Triassic) of Monte San Giorgio (Ticino, Switzerland). und seine Fossilien, III. Die tierischen Fossilien des Geologia Insubrica, 3(1):23-31. Kupferschiefers 2. Vertebraten. der Aufschluss, Mutter, R.J. 1998b. Zur systematischen Stellung einer 28:297-352. Bezahnungsreste von Acrodus georgii sp. nov. (Sela- Shen, S.-Z. and Clapham, M.E. 2009. Wuchiapingian chii,Hybodontoidea) aus der Grenzbitumenzone (Mit- (Lopingian, late Permian) brachiopods from the Epis- tlere Trias) des Monte San Giorgio (Kanton Tessin, kopi Formation of Hydra Island, Greece. Palaeontol- Schweiz). Eclogae Geologicae Helvetiae, 91:513- ogy, 52(4):713-743. 519. Trikolas, N. 2008. Geological study of the wider area of Mutter, R.J., de Blanger, K., and Neuman, A.G. 2007. Aegialia and Kalavryta, Unpublished PhD Thesis, Elasmobranchs from the Lower Triassic Sulphur National Technical University of Athens, Athens, Mountain Formation near Wapiti Lake (BC, Canada). Greece. (In Greek) Zoological Journal of the Linnean Society, 149:309- Turner, S., Burrow, C.J., Schultze, H.-P., Blieck, A., Reif, 337. W.-E., Rexroad, C.B., Bultynck, P., and Nowlan, G.S. Mutter, R.J., Neuman, A.G., and de Blanger, K. 2008. 2010. False teeth: conodont-vertebrate phylogenetic Homalodontus nom. nov., a replacement name for relationships revisited. Geodiversitas, 32(4):545-594. Wapitiodus Mutter, de Blanger and Neuman, 2007 Vachard, D., Martini, R., and Zaninetti, L. 1995. Le Mur- (Homalodontidae nom. nov., ?Hybodontoidea), pre- gabien á Fusulinoides des iles d'Hydra, Crète et occupied by Wapitiodus Orchard, 2005. Zoological Mytilène (Permien supérieur de Grèce). Geobios, Journal of the Linnean Society, 154:419-420. 28(4):395-406. Nestell, M.K. and Wardlaw, B.R. 1987. Upper Permian Vachard, D., Rettori, R., Angiolini, L., and Checconi, A. conodonts from Hydra, Greece. Journal of Paleontol- 2008. Glomomidiella gen. n. (Foraminifera, Miliolata, ogy, 61(04):758-772. Neodiscidae): a new genus from the late Guadalu- Rees, J. and Underwood, C.J. 2002. The status of the pian–Lopingian of Hydra Island. Rivista Italiana di shark genus Lissodus Brough, 1935, and the position Paleontologia e Stratigrafia, 114(3):349-361+2 pls. of nominal Lissodus species within the Hybodon-

9