Paleontological Research, vol. 9, no. 1, pp. 79–84, April 30, 2005 6 by the Palaeontological Society of Japan A new genus of the family Amblypteridae (Osteichthyes: Actinopterygii) from the Lower Permian of Eastern Europe ARTE´ M M. PROKOFIEV Department of Fishes and Fish-like Vertebrates, Paleontological Institute – PIN, Russian Academy of Sciences, Profsoyuznaya Street, 123, Moscow 117997, Russia (e-mail: [email protected]) Received February 14, 2002; Revised manuscript accepted February 22, 2005 Abstract. A new genus and species of the family Amblypteridae, Tchekardichthys sharovi,fromthe Lower Permian of Eastern Europe (Perm Region of Russia) is described. It can be distinguished from all the known members of the family in the position of the fins and number of fin rays, characters of scalation and cranial roofing bones ornamentation, etc. The newly described taxon apparently lived in estuarine or brackish-water habitats. Key words: actinopterygians, Amblypteridae, Eastern Europe, Lower Permian, new genus and species The elonichthyiform family Amblypteridae is rep- second is situated at the mouth of the Tchekarda resented by five genera and numerous species from River and immediately downstream of the latter, and the Carboniferous to Lower Permian of France, Ger- the third one is situated on the left bank of the Sylva many, Czech Republic, India (Kashmir) and South River 850 m downstream from the mouth of the America, and from the Upper Permian of the Ural Tchekarda River. The specimens described herein are region in Eastern Europe (Agassiz, 1833–1844; Berg, found in the second site. The Tchekarda layers belong 1940; Dunkle and Schaeffer, 1956; Berg et al., 1964; to the Koshelevskaya Formation of the Irenskian Re- Heyler, 1969, 1976, 1997; Beltan, 1978). From Eastern gional Division of the Kungurian Stage (uppermost Europe two genera (Amblypterus Agassiz and Am- Lower Permian) (Anonymous, 1993). This locality blypterina Berg) are known from the Upper Permian contains numerous remnants of plants and insects (Kazanian Regional Division, which is correlated with (Ponomareva et al., 1998), but the fishes are extremely Wordian-Capitanian), and no representatives of the rare. The Tchekardian deposits were formed in the family have been found hitherto in the Lower Permian initial stage of arid lithogenesis in shore-sea con- of this region. However, two undescribed specimens ditions; they represent the underwater and surface of Amblypteridae from the terminal Lower Permian cones of the source of a mountain river delta (Pono- Tchekarda Locality (Perm Region of Russia) were mareva et al., 1998). discovered recently in a collection of the Paleonto- logical Institute in Moscow (PIN). These specimens Systematic paleontology represent a new genus and species, which is described in the present paper. Order Elonichthyiformes (sensu Kazantseva- Selezneva, 1977) Notes on geography and stratigraphy Family Amblypteridae Romer, 1945 The Tchekarda locality is situated on the north- Diagnosis.—See Gardiner (1963: 290), with addi- western slope of Krasnaya Gora (¼ Red Mountain) tional remarks of Dietze (2000). on the left bank of the Sylva River, 800 m northwest Remarks.—Gardiner (1963) mentioned three gen- from Tchekarda Village (Figure 1). This locality is era (Amblypterus, Paramblypterus and Amblypterina) divided into three sites, one of them is situated 160 m in this family. However, the genus Paramblypterus upstream from the mouth of the Tchekarda River, the Sauvage sharply differs from the Amblypteridae by 80 Arte´m M. Prokofiev Figure 1. Maps of a part of the Western Ural region illustrating the location of the fossil site. Scale bars: a.50km;b.2km. the fragmentation of the cheek bones and belongs to Carboniferous of Uruguay and the Carboniferous- the family Paramblypteridae (Blot, 1966). However, Permian of Brazil to the Amblypteridae. According to recently Dietze (2000) united Paramblypterus and the original description (Dunkle and Schaeffer, 1956), Amblypterus into a single family again; according to the genus Tholonotus from the Lower Permian of her analysis (p. 954, text-fig. 20) these genera are Brazil also undoubtedly belongs to this family. The sister-groups, so their separate familial position can- taxonomic position of the genus Korutichthys,origi- not be excluded. Beltan (1978) has added two new nally referred to the Amblypteridae (Kazantseva- genera (Daphnaechelus and Tholonosteon)fromthe Selezneva, 1980), is uncertain (see discussion). New Lower Permian fish from Eastern Europe 81 Figure 2. Tchekardichthys sharovi g. et sp. nov., Lower Permian (Kungurian) of Tchekarda Locality (Perm Region, Russia): a. holo- type, PIN, nr. 1698-1 (natural size); b. paratype, PIN, nr. 1698-2 (natural size). Tchekardichthys gen. nov. Etymology.—Species named in honour of the col- lector, A.G. Sharov. Type species.—Tchekardichthys sharovi sp. nov.; Diagnosis.—Small fish of about 8 cm length. Parie- monotypic genus. tals approximately three times shorter than frontals. Etymology.—From Tchekarda locality, and -ichthys Dermosphenotic contacting the nasal. Suspensorium (Greek), for a fish; masculine. nearly vertical. Dermohyal present, but epipreopercle Diagnosis.—Same as that of the type species. absent. Opercle 1.5 times deeper than subopercle. Bones of skull and pectoral girdle ornamented with Tchekardichthys sharovi sp. nov. coarse ridges of ganoine. Trunk deeply fusiform. Cau- dal peduncle length equals to its least depth. Dorsal Holotype.—PIN, nr. 1698-1 (Figure 2,a), incomplete contour much arched in front of dorsal fin. Dorsal fin specimen lacking most parts of the skull and of the origin in front of the anal fin and partly above it. Both pectoral fins, with counterpart; left bank of the Sylva dorsal and anal fins large and triangular, deeper than River at the mouth of the Tchekarda River, Suksun long. Anal fin base slightly shorter than dorsal fin Division of Perm Region, Russia; upper part of Lower base. Pelvic fins of moderate size, placed slightly Permian (Kungurian); collector: A.G. Sharov, 1950th. nearer to pectorals than to anal. All fins with minute Paratype.—PIN, nr. 1698-2 (Figure 2,b), nearly fringing fulcra and with rays articulated and distally complete specimen, with incomplete counterpart, from bifurcating. Approximate numbers of fin-rays: dorsal the type locality. 25; anal 20; pelvic 16. Flank scales moderately large, 82 Arte´m M. Prokofiev approximately as deep as long, with thin but conspic- Range.—Known only from the type locality and uous longitudinal ridges. Distinctive patches of small horizon. scales under bases of dorsal and anal fins absent. Ridge scutes on dorsal contour of body before dorsal Discussion fin origin 15 in number. Description (Figure 3,a).—Besides the characters The characters of Tchekardichthys well agree with given in the diagnosis there are several additional Gardiner’s (1963) diagnosis of the Amblypteridae. features. The maximum body depth is contained ap- Unfortunately the skull is incompletely known in this proximately 3 times in the total length of the fish. The new genus so that most of the characters used by Di- caudal peduncle is moderately deep, being two times etze (2000) for definition of the family Amblypteridae smaller than the maximum body depth. The head is are unknown. However, Tchekardichthys agrees with moderately long, being approximately one-fifth of the Dietze’s diagnosis of the Amblypteridae in possession total length. The snout is rounded in dorsal view. The of a little ornamentation of the scales. The new genus orbit is relatively small. The jaws and a part of the differs from Amblypterus Agassiz 1833 in the anal fin rostral portion of the skull are missing. The roofing base being shorter than (vs. approximately equal to) bones of the skull are ornamented with coarse longi- the dorsal fin base, in the pelvic fins being positioned tudinal ridges of ganoine. The postrostral is rather slightly closer to the pectorals than to the anal fin broad at the contact with the frontals. The nasal bones (vs. the opposite condition in Amblypterus)andinthe are long, trapezoidal. The frontals are the longest scales being more distinctly ridged (vs. smooth or bones of the skull roof (Figure 3,b), subrectangular in nearly so). Tchekardichthys is distinguished from Am- shape, and slightly asymmetrical. The parietals are blypterina Berg, 1940 in the much shorter dorsal fin small and almost square, both of the same size and (twice longer than the anal fin and comprising ap- shape. The pineal foramen is absent. Both dermos- proximately 50 rays in Amblypterina), in the much phenotic and dermopterotic are large and diamond- more numerous ridge scutes before the dorsal fin (15 shaped. The dermopterotic is nearly 1.2 times longer vs. only 3 in Amblypterina), in the absence of patches than the dermosphenotic. The elongate subtriangular of small scales under the bases of the unpaired fins, posttemporals are preceded by a pair of the nearly and in the scales on the body sides nearly as deep as triangular, narrow extrascapulars. The presence or long (vs. deeper than long). The new genus differs absence of a medial extrascapular cannot be deter- from Tholonotus Dunkle et Schaeffer, 1956 in the mined owing to preservation of the specimens. The smaller number of dorsal and anal fin rays (25 and 20 bones of the suborbital series are not clearly seen. The vs. 37 and 27 in Tholonotus),intheanalfinoriginbe- upper branch of the preopercle is not fragmented into ing in front of the posterior extremity of the dorsal fin small separate elements. The subopercle is 1.5 times and in the smaller body size (up to 8 cm vs. 13 cm in lower than the opercle. Tholonotus). Tchekardichthys differs from Daphnae- The dorsal fin origin is remote. The anal fin is ori- chelus Beltan, 1978 in the large parietals and striated ginated under mid-base of the dorsal fin (holotype) (vs. tuberculated) ornamentation of the cranial bones. or slightly anteriorly (paratype). The pectoral fins are The new genus is distinguished from Tholonosteon incompletely preserved. The pelvic fins are deeper Beltan, 1978 in the shorter caudal peduncle (notice- than long.