A New Species of Sangiorgioichthys Tintori & Lombardo, 2007 N

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Kolumnentitel links: Wen-qi Chen et al. Kolumnentitel rechts: A new species of Sangiorgioichthys TinTori & Lombardo, 2007 N. Jb. Geol. Paläont. Abh. 273/1 (2014), 65–74 Article E E Stuttgart, July 2014

N. Jb. Geol. Paläont. Abh. Article Stuttgart, July 2014

A new species of Sangiorgioichthys TinTori & Lombardo, 2007 (Actinopterygii; Semionotiformes) from the Pelsonian (Anisian, Middle Triassic) of Guizhou Province, South China

Wen-qi Chen, Zuo-yu Sun, Andrea Tintori, and Da-yong Jiang With 3 figures and 1 table

Abstract: Sangiorgioichthys yangjuanensis sp. nov., from the Middle Triassic (Pelsonian, Middle Anisian) vertebrate fossiliferous layers of the upper Member of the Guanling Formation in the Dry Well Site, near Yangjuan Village, Panxian County, Guizhou Province, South China, is herein described. The presence of one single anterior infraorbital, a large infraorbital at the posteroventral corner of the orbit, one ventral suborbital covering the quadrate and quadratojugal, small dorsal fin limited to the area between the origin of the pelvic and anal fins supports the generic assignment of the new taxon. Of the known Sangiorgioichthys species, it closely resembles S. sui in having the median part of the supratemporal commissure lodged in the parietals, the presence of a sensory canal entering the posteriormost supraorbital, an elongated supramaxilla fitting in an excavation of the dorsal border of the maxilla, etc., which do not occur in S. aldae and S. valmarensis, although phylogenetic signal of these features are pending. The new taxon differs from S. sui in the number of dorsal suborbitals, the structure and row number of the scales, and also the dermosphenotic dorso-ventrally elongated, rectangular in shape, with the temporal canal entering the element at the dorsal half, then turning ventrally into the infraorbital canal rather than going posterior to the supraorbital canal.

Key words: New taxon, actinopterygian, Sangiorgioichthys, Pelsonian, Triassic, Guizhou Province.

1. Introduction López-Arbarello et al. 2011; Lombardo et al. 2012). The type species of the genus, Sangiorgioichthys al- The genus Sangiorgioichthys Tintori & Lombardo, dae Tintori & Lombardo, 2007, was described from 2007 is the oldest certain ‘semionotiform’ known from the Late Ladinian (Middle Triassic) Kalkschieferzone the Middle Triassic of the Tethys, which presents a (upper member of the Meride Limestone) and Perledo- unique combination of morphological characters, i.e., Varenna Formation in the Monte San Giorgio of Italy a single anterior infraorbital, the presence of one or and Switzerland and Lario Lake of Italy, respectively two ventral suborbitals laterally covering the quadrate (Bellotti 1857; Deecke 1889; De Alessandri 1910; and quadratojugal, small dorsal fin limited to the area Tintori & Lombardo 2007). López-arbarello et al. between the origin of the pelvic and anal fins, dorsal (2011) extended spatially and temporally the record of ridge scales conspicuous only with a small posterior the genus by adding a second species, Sangiorgioich- spine, and a complete row of scales above the last thys sui, from the upper Member of the Guanling For- scale of the lateral line (Tintori & Lombardo 2007; mation (Middle/Late Anisian, Middle Triassic) near

Fig. 1. A – Map of the study area showing the fossil locality (modified from Motani et al. 2008); B – generalized lithostrati- graphic log showing the fossil-bearing layers (modified from Sun et al. 2006 and Motani et al. 2008).

Dawazi village, Luoping County, Yunnan Province, ulation, etc., which adds new information to the early South China. A third species, Sangiorgioichthys val- history of the order and helps in establishing character marensis, was recorded from the Late Ladinian Ka- polarities (Tintori & Lombardo 2007; Cav i n 2010; lkschieferzone (Meride Limestone) of the Monte San López-arbarello et al. 2011; López-arbarello 2012; Giorgio area, the same unit yielding the type species Cav i n et al. 2013). (Lombardo et al. 2012). Sangiorgioichthys occupies a Here, we report on a fourth species of Sangiorgio- critical position within the Semionotiformes because ichthys from the Middle Triassic (Pelsonian, Middle it shows several primitive semionotiform characters Anisian) vertebrate fossiliferous layers of the upper such as short snout, low number of anterior infraor- Member of the Guanling Formation, about 50 m be- bitals, the lack of specialized dentition and scale artic- low the base of the overlying Yangliujing Formation, A new species of Sangiorgioichthys TinTori & Lombardo, 2007 67 near Yangjuan Village, Panxian County, Guizhou 3. Systematic palaeontology Province, South China (Sun et al. 2006; Fig. 1A, B). Subclass Actinopterygii Cope, 1887 The Yangjuan locality, well known in publications as Infraclass Neopterygii Regan, 1923 the ‘Panxian Fauna’ during the past decade, yields a Order Semionotiformes Arambourg & Bertin, 1958, remarkable assemblage of marine reptiles (more than sensu Olsen & McCune, 1991 11 species, see Motani et al. 2008; Jiang et al. 2009 Family incertae sedis and reference therein; Li et al. 2011), as well as a few actinopterygian genera (Sun et al. 2008). The subholo- Genus Sangiorgioichthys Tintori & Lombardo, 2007 stean Colobodus baii and Saurichthys (Sinosaurich- thys) longipectoralis and Yelangichthys macrocepha- Type species: Sangiorgioichthys aldae Tintori & Lombar- lus are the first three fish species that have already do, 2007 been described (Sun et al. 2008; Wu et al. 2011, 2013) and there remain several undescribed taxa. The pur- Other species included: Sangiorgioichthys valmarensis Lombardo et al., 2012; Sangiorgioichthys sui López-arba- pose of this paper aims to present the erection of a rello et al., 2011; Sangiorgioichthys yangjuanensis sp. nov. new Sangiorgioichthys species, further bettering the (this paper). knowledge of fish diversity of the Panxian Fauna. Emended diagnosis: One anterior infraorbital only; a very large infraorbital at the posteroventral corner of the orbit, 2. Material and methods almost attending the anterior margin of the preopercle; one or two ventral suborbitals laterally covering the quadrate The only known specimen described herein has been and quadratojugal; small dorsal fin, limited to the area be- found in the upper Member of the Guanling Forma- tween the origin of the pelvic and anal fins; complete row tion of the Yangjuan locality. It was collected from the of scales in the body lobe above the last scale of the lat- layer 89 (Fig. 1A) of the Dry Well Site (N25°31’25’’, eral line; dorsal ridge of scales conspicuous, but with only a E104°53’55’) during the joint excavation hold by the small posterior spine. Peking University, University of California (Davis) Geographic distribution: Rio Vallone and Ca’del Frate and Università degli Studi di Milano in 2006 (Mo- (Viggiù, Varese, Italy), Perledo (Italy), Val Mara D (Meride, tani et al. 2008). Now, it is stored in the paleontologi- Canton Ticino, Switzerland); Village of Dawazi (Luoping cal collections of the Geological Museum of Peking County, Yunnan Province, South China) and Yangjuan University (institutionally abbreviated as GMPKU- (Panxian County, Guizhou Province, South China). P). Preparation has been mechanically done using Stratigraphic distribution. Kalkschieferzone of the fine steel needles under binocular microscope at the Meride Limestone and Perledo Member of the Varenna For- GMPKU laboratory. Drawings were made by mean of mation (both Ladinian, Late Middle Triassic), and Verte- a camera-lucida mounted on a WILD M8 microscope brate fossiliferous layers of the upper Member of Guanling and later digitalized. Formation (Middle/Late Anisian, Middle Triassic). Skull bones are named according to the use of most authors working on actinopterygians. The canal bearing bones posterior to the antorbital and anterior to the Sangiorgioichthys yangjuanensis sp. nov. orbit (i.e., that do not participate in the margin of the Figs. 2-3 orbit) are referred to as ‘anterior infraorbitals’ follow- Etymology: From Yangjuan, the name of the village, the ing Wenz (1999). The relative position of the fins and locality where the specimen was found. the scale counts is expressed in a pterygial formula following that of Westoll (1944). Holotype: GMPKU-P-1377, the only known specimen, a fairly well preserved specimen, but the scales within the re- Anatomical abbreviations: a.io, anterior infraorbital; ang, gion of caudal peduncle and most part of the tail are missing angular; ant, antorbital; br, branchiostegal rays; cl, clei- because of damage during excavation. thrum; d, dentary; dpt, dermopterotic; dsph, dermosphenotic ; exsc, extrascapular; fr, frontal; io, infraorbital; iop, in- Type locality: Near Yangjuan Village, Xinmin District, teropercle; mx, maxilla; na, nasal; op, opercle: pa, parietal; Panxian County, Guizhou Province, China. plp, pit line posterior; pmx, premaxilla; pop, preopercle; pt, posttemporal; q, quadrate; ro, rostral; sang, surangular; scl, Type horizon: Upper Member, Guanling Formation, cono- supracleithrum; so, supraorbital; sop, subopercle; sbo, sub- dont biozone of Nicoraella kockeli; Pelsonian, Anisian, orbital. Middle Triassic (Sun et al. 2006). 68 Wen-qi Chen et al.

Fig. 2. Sangiorgioichthys yangjuanensis sp. nov. A – Photograph, and B – line drawing of GMPKU-P-1377 (holotype). Scale bars equal 5 mm.

Diagnosis: A small-sized Sangiorgioichthys morphologi- middle of the body (0.64 SL), limited to the area between cally similar to Sangiorgioichthys sui, but distinguishable the origin of the pelvic and anal fins. The anal fin is located with 32 vertical scale rows and more or less 17 horizontal in the posterior quarter of the body (0.80 SL). All of the pre- ones, a single row of three dorsal suborbitals; dermosphen- served fins (i.e., all fins except the caudal fin) are preceded otic dorso-ventrally elongated, rectangular in shape with the by basal fulcra, then following by a series of small fringing temporal canal entering the element at the posterior half, fulcra. then turning ventrally into the infraorbital canal instead of Ornamentation. All dermal bones are ganoin-covered, going on into the posterior supraorbital canal; flank scales mostly by the ganoin tubercles and ridges. The elements of with straight posterior borders. Pterygial formula: the snout and shoulder girdle, the anterior 1/3 of the frontal, most of the mandible (including the dentary, surangular, D19 angular), the dorsal half of the 1st and 2rd infraorbitals, and T32 P7 A17C? the triangular anterior infraorbital are smooth on the surface. There are very sparse ganoin tubercles on the antero- Description: Measurement data from the only known spec- dorsal portion of the opercle, the rest of which is covered imen (holotype) is provided in Table 1. It is a small-sized by strongly radiated ganoin ridges. Ornamentation of the fusiform fish. The maximum body depth before the dorsal subopercular is similar to that of the opercular, however, fin is 0.43 of the SL. The head is approximately as long as ganoin ridges are restricted to the area close to the posterior deep, the head length being about 0.32 of the SL. The snout and ventral margins. Several rows of toothed ridges on the is very short, the estimated preorbital length is about 0.8 of cleithrum are visible. the longitudinal diameter of the eye and about 0.22 of the Snout. The rostral is a small irregularly trapezoidal head length. The depth of the caudal peduncle is about 0.14 element, carrying ethmoidal commissure that is traced by of the SL. The insertion of the pelvic fins is just behind the one pore. The nasals are very long and narrow ribbon-like middle of the body (0.59SL), closer to the anal fin than to bones, which are narrowing and laterally curved anteriorly. the pectoral fins. The small dorsal fin is located behind the They are scatteredly preserved and partially overlapped A new species of Sangiorgioichthys TinTori & Lombardo, 2007 69

Table 1. Measurements of the holotype of Sangiorgioichthys yangjuanensis sp. nov.

each other. The supraorbital sensory canal goes through the between the first infraorbital and the antorbital and tightly nasals, traced by several pores. The antorbital is a L-shaped bound to the dorsal margin of the antorbital. For the re- bone, with the horizontal portion approximately as long as maining infraorbitals, in anterior to posterior direction, the depth of the vertical portion. It is located anteriorly to the first infraorbital (Io1) is massive, slightly deeper than the first infraorbital and sutures anterodorsally with the long, and trapezoid in shape with a convex ventral border small triangular anterior infraorbital. contacting the anterior dorsal margin of the maxilla; the Skull roof. The frontal is rectangular in shape, a little second infraorbital (Io2) is longitudinally elongated, about wider posteriorly than anteriorly, with the length versus the 3 times longer than deep; the third infraorbital (Io3) is a maximum width being ca. 2.5. Only a single frontal is pre- small, squarish bone; the fourth one (Io4), at the postero- served, with the posterior portion broken. The interfrontal ventral corner of the orbit, is the largest, irregularly trap- suture is somewhat straight. The interorbital constriction ezoid in shape, and reaches posteriorly the anterior margin is clear. Only the right parietal is preserved, which is rec- of the preopercle, separating the dorsal suborbitals from the tangular in shape with the posteromedial portion expanded ventral one; the last two infraorbitals (Io5, Io6), behind the excluding the extrascapulars from one another. The lateral orbital, are dorso-ventrally rectangular relatively small, the margin of the parietal is almost as long as the dermopter- dorsal one being 1.5 times deeper than the ventral one. The otic, half of the length of the frontal. The dermopterotic is infraorbital sensory canal goes through the Io1-Io4 along also subrectangular in shape with an antero-ventral expan- their ventral margin, and then turns dorsally into Io5 and sion, about twice longer than deep. Io6 along the posterior margin. The supraorbital sensory canal traverses the frontal, Cheek bones. The preopercle is very narrow, crescent approximately following its lateral border, describing a in shape, and reaches the dermopterotic dorsally and the sinuous line, and to the posterior end of the ossification it lower jaw ventrally. The dorsal ramus is vertically orien- becomes blind. No trace of the supraorbital sensory canal tated, partially overlapped by the dorsal suborbitals; the is visible in the parietal. A groove margined by a ridge run- ventral ramus gently curved anteroventally without any ning in the posterior region of the parietal might represent prominent expansions. The sensory canal runs along its the middle pit-line. posterior margin, traced by a series of pores. There is a row Circumborbial series. More than three supraorbitals of three suborbitals, interpreted as the dorsal suborbitals be- are preserved: they are rectangular in shape, of which the cause they are located dorsal to the large infraorbital at the anteriormost one is elongate, tapering anteriorly. posteroventral corner of the orbit: the first and second are The posteriormost supraorbital is pierced by three pores, rather small, somewhat triangular in outline; the third one showing the path of the orbital canal. is dorso-ventrally elongated, twice as deep as the other two. The dermosphenotic is dorso-ventrally rectangular in A triangular element, ventral to the large infraorbital at the shape, occupying the posteroventral corner of the orbit: it posteroventral corner of the orbit, covers the area occupied carries the temporal canal at the dorsal half of the element, by the quadrate and quadratojugal. It is interpreted as the then turning ventrally into the infraorbital canal instead of ventral suborbital following Tintori and Lombardo (2007), going on into the posterior supraorbital canal. López-arbarello et al. (2011), and Lombardo et al. (2012). Seven infraorbitals are preserved with the anteriormost Palatoquadrate. Only the condyles of the quadrate and one being probably the anterior infraorbital. The possible quadratojugal are visible. anterior infraorbital is small, triangular in shape, located Opercular series and branchiostegal rays. The oper- 70 Wen-qi Chen et al.

Fig. 3. Sangiorgioichthys yangjuanensis sp. nov. A – Photograph, and B – line drawing of the skull of GMPKU-P-1377 (holotype). Scale bars equal 5 mm.

cle is a shield-like element, which becomes broader ventral- and interopercle respectively. The maximal depth of the ly than dorsally and slightly deeper than long. The anterior subopercle, at the level of the anterodorsal process is about border of the opercle is slightly concave and the other bor- half the depth of the opercle. The interopercle is short and ders are convex. The subopercle has straight anterodorsal robust, roughly triangular in shape. and anteroventral borders articulating with the preopercle Five branchiostegal rays are preserved. The dorsalmost A new species of Sangiorgioichthys TinTori & Lombardo, 2007 71 branchiostegal ray is notably larger and more strongly orna- ones at the level of the origin of the dorsal fin. The anterior mented than the other ones, resembling the so-called bran- flank scales are rectangular, up to twice deeper than long, chiopercle of Amia (grande & bemis 1998: 97) and other with straight posterior borders and smooth surface. More halecomorphs. The remaining branchiostegal rays have the posteriorly the scales become gradually rhomboidal. Scales usual acuminate shape. on the belly are rectangular in shape, longer than deep. The Jaws and dentition. The upper jaw consists of premax- dorsal ridge scales between the head and the dorsal fin has illa, maxilla and supramaxilla. The premaxilla is a triangu- very short posterior spine. The scales of the lateral line have lar element with the nasal process. The oral margin bears small slits and rounded pores. There are preanal scutes, but 4 relatively long conical teeth. The maxilla is elongate and the number is uncertain due to the preservation. slender, with an indented posterior margin. The dorsal border of the maxilla is concave in the posterior half of the bone, where the supramaxilla abuts, and in the anterior half 4. Discussion of the bone there is a second concavity where the convex ventral border of the first infraorbital allocates. A complete The presence of one single anterior infraorbital, a large row of small conical teeth is present almost along the whole infraorbital at the posteroventral corner of the orbit, oral margin of the maxilla. The single supramaxilla is elon- one ventral suborbital covering the quadrate and quad- gate, oval in shape, fitting in the posterior concavity of the ratojugal, small dorsal fin limited to the area between maxilla ventrally. the origin of the pelvic and anal fins support the inclu- Dentary, angular, surangular are distinguishable in the lower jaw. The dentary is slender, with a relatively short pos- sion of the specimen described herein into the genus teroventral process, half the length of the angular. It bears Sangiorgioichthys tintori & lombardo, 2007 (Tin- a series of marginal teeth, which resemble the premaxillary tori & lombardo 2007; López-arbarello et al. 2011; teeth in size and shape. The angular is massive, squarish in Lombardo et al. 2012). The genus Sangiorgioichthys outline, with some radiated shallow groove on the surface. Tintori & Lombardo, 2007 possesses the semionoti- The quadrate fossa is visible on the lateral margin of the angular. The surangular is partially overlapped by the maxilla form characters proposed by previous authors such as and the infraorbitals under the orbit, thus its details is un- the presence of anterior infraorbitals, the lack of gular certain. The dentary and the angular carry the mandibular plates (Olsen & McCune 1991; Cav i n & suteethorn sensory canal along their ventral margin, marked by a series 2006; Cav i n 2010; Schröder et al. 2012), and possibly of opening pores. represents a rather primitive form of semionotiforms Shoulder girdle and paired fins. The dermal compo- nents of the shoulder girdle include the extrascapulars, post- because of its short snout, the low number of anterior temporals, supracleithrum, cleithrum and several postcleithra. infraorbitals, the unspecialized dentition or scale artic- The extrascapulars are subtriangular in shape and tapering ulation (López-arbarello et al. 2011), the completely medially. They are medially separated by the posteromedi- covered cheek, a relatively short nasal process of the ally expanded parietals. The supratemporal commissure runs premaxilla, well-developed pit-lines in the parietal through the extrascapular along its posterior margin marked and dermopterotic, etc. Tintori & lombardo (2007) by a serie of small pores, then curves anterodorsally and enters the parietal to meet the posterior pit line. The posttem- tentatively placed Sangiorgioichthys in the family poral is broad, semicircular in outline. The supracleithrum is Semionotidae Woodward, 1890 pro parte, which was broad dorsally and narrows ventrally. The temporal sensory accepted by Lombardo et al. (2012). However, López- canal runs through the dermopterotic, the extrascapular and arbarello et al. (2011) questioned this family assign- the posttemporal along their ventral margin. It enters the su- ment because the family Semionotidae Woodward, pracleithrum at the dorsal border by a row of three pores, then following a posterior slit. The cleithrum is partially preserved 1890 pro parte is probably non-monophyly and it has and partially overlapped by the subopercle and branchioste- even enlarged to be a “waste-basket” for many taxa of gals.Two postcleithra are present. basal neopterygians with uncertain family assignment The paired fins are rather poorly preserved; only some ranging from the latest Permian to the late Cretaceous basal fulcra are observed. They are small in size, of which (López-arbarello 2012). Although the family Semi- the pelvic fin is inserted at the 7th scale row. Unpaired fins. The dorsal and anal fins are incom- onotidae sensus Olsen & maccune (1991) or López- pletely preserved with their anterior part missing. They are Arbarello (2012) that are strictly restricted to Semi- relatively small. The dorsal fin is originated at the 19th scale onotus and Lepidotus or even only Semionotus were row. It consists of at least six lepidotrichia, preceded by four considered, Sangiorgioichthys cannot be confidently th basal fulcra. The anal fin is inserted at the 17 scale row. It assigned to them as yet and also to any other semi- consists of at least seven lepidotrichia, preceded by three ópez basal fulcra. Fringing fulcra are visible for the anal fin. onotiform or ginglymodian families revised by L - The caudal fin is too fragmentary to provide any infor- arbarello (2012). Therefore, we still propose to place mation. it as family incertae sedis within semionotiforms Squamation. The squamation consists of 32 transver- pending further taxonomic and phylogenetic investiga- sal rows of scales along the lateral line and 17 horizontal tions for the latter, in particular the interrelationships 72 Wen-qi Chen et al. of Triassic taxa. Among the known Sangiorgioichthys in an excavation of the dorsal border of the maxilla species, the new taxon clearly distinguished from the etc., which do not occur in Sangiorgioichthys aldae two Late Ladinian west Tethyan representatives, San- and Sangiorgioichthys valmarensis. These morpho- giorgioichthys aldae Tintori & lombardo, 2007 and logical similarities serve to indicate a possible close Sangiorgioichthys valmarensis Lombardo et al., 2012, relationship between the Asian species. However, they by the following features: the median part of the su- clearly differ in some details: the pattern of the dorsal pratemporal commissure lodged in the parietals; the suborbitals between the infraorbitals and the preoper- presence of a sensory canal entering the posteriormost cular is identical on both the new taxon and Sangior- supraorbital, elongate supramaxilla fitting in an exca- gioichthys sui, however, the number differs, i.e., three vation of the dorsal border of the maxilla; infraorbitals verus two. The dermosphenotic of the new taxon is anterior to the large infraorbital at the posteroventral dorso-ventrally elongated, rectangular in shape, with corner of the orbit elongate rather than triangular in the temporal canal entering the element at the dorsal shape, although the potential implications of these half, then turning ventrally into the infraorbital canal, above-mentioned features for systematics are pend- whereas the dermosphenotic of Sangiorgioichthys sui ing. The sensory canal entering the supraorbital bones is usually drop-like in shape, with the temporal canal was named as the orbital sensory canal by López-ar- traversing the dorsal margin of the elements, then go- barello & Sferco (2011) in Late Jurassic semionoti- ing on into the posterior supraorbital canal rather than fom Scheenstia Zappi, which is also present in many turning ventrally into the infraorbital canal. They also post-Triassic semionotiforms like Tlayuamichin, Mac- differ in proportion and fin count: the new taxon is rosemimimus, Lepisosteus and Atractosteus (grande small-sized, with the TL of 68 cm, much smaller than 2010; lópez-arbarello & alvarado-ortega 2011; Sangiorgioichthys sui, which is usually more than 10 López-arbarello 2012) and halecomorphs like Ophi- cm in total length; The new taxon has 32 transverse opsis procera and Ophiopsis attenuata (Bartram scale rows with 17 horizontal ones at the level of the 1975) as well as in some Late Triassic pholidophorids origin of the dorsal fin whereas Sangiorgioichthys (Arratia 2013). Among actinopterygians, the en- sui has 32-36 transverse scale rows with 20 horizonal closure of the supratemporal commissure within the ones. One last certain difference regards the structure parietals is also present in Tetragonolepis, and some of posterior of the flank scale: it is finely serrated in Lepidotes species like Lepidotes gloriae Thies, 1989, Sangiorgioichthys sui, but almost straight in the new as well as some living teleosts like Abramis brama. taxon. Also, the dentition of Sangiorgioichthys aldae and Based on the above morphological comparison, Sangiorgioichthys valmarensis are quite distinguish- Sangiorgioichthys yangjuanensis sp. nov. shows a set able: Sangiorgioichthys aldae has edentulous maxilla of characters that support the erection of a new spe- and conical teeth only concentrated in the anterior cies distinct from the already known species of San- region of the mouth (premaxilla and anterior part of giorgioichthys. The report of Sangiorgioichthys from the dentary), and Sangiorgioichthys valmarensis has the vertebrate fossiliferous layers of the Middle Tri- small button-like teeth on palatal bones, which differ assic (Pelsonian, Middle Anisian), Panxian County, from the state of the new taxon. Besides these differ- Guizhou Province, South China, further better the ences, the number and arrangement of the suborbitals knowledge of fish diversity of the Panxian Fauna, al- are also different: Sangiorgioichthys aldae has nine though there remain several undescribed fish taxa. suborbitals, of which the dorsalmost four are arranged in a double series followed ventrally by a single row of Acknowledgements three, then two ventral suborbitals laterally covering the quadrate and quadratojugal. Sangiorgioichthys Thanks go to those who helped in collecting the fossils. valmarensis has a single row of four dorsal suborbitals, This study was financially supported by Peking University, and one ventral suborbital; the new taxon has a single NSFC (grant 40920124002, 41372016), State Key Labora- tory of Palaeobiology and Stratigraphy (Nanjing Institute row of three dorsal suborbitals and one ventral sub- of Geology and Palaeontology, CAS) (No. 123107, 123102, orbital. Morphologically, the new taxon shares with 143108). We also thank lionel cav i n (Muséum d’Histoire Sangiorgioichthys sui several characters of the skull naturelle, Genéve, Switzerland) for reviewing the manu- such as the number and statement of the extrascapu- script, and the editor-in-chief Dr. guenter schweigert for lars, the presence of a sensory canal entering the pos- his advice. teriormost supraorbital, elongate supramaxilla fitting A new species of Sangiorgioichthys TinTori & Lombardo, 2007 73

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Survey of New South Wales, Palaeontology, 4: 1-56. Addresses of the authors: Wu, F., Chang, m., sun, Y. & Xu, g. (2013): A new sau- Wenqi Chen, ZuoYu Sun (corresponding author), DaYong richthyiform (Actinopterygii) with a crushing feed- Jiang, Department of Geology and Geological Museum, ing mechanism from the Middle Triassic of Guizhou Peking University, Beijing 100871, P. R. China; (China). – PLoS ONE 8: e81010. doi:10.1371/journal. e-mail: [email protected]. pone.0081010. Wu, F., Sun, Y., Xu, G., Hao, W., Jiang, D. & Sun, Z. (2011): Wenqi Chen, State Key Laboratory of Palaeobiology and New saurichthyid actinopterygian fishes from the Ani- Stratigraphy (Nanjing Institute of Geology and Palaeontol- sian (Middle Triassic) of southwestern China. – Acta ogy, CAS); Palaeontologica Polonica, 56: 581-614. Andrea Tintori, Dipartimento di Scienze della Terra, Uni- versità degli Studi di Milano, via Mangiagalli 34, I-20133 Manuscript received: March 9th, 2014. Milano, Italy. Revised version accepted by the Stuttgart editor: May 5th, 2014.