identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
4C16252EAC05FFBD918ECBEDFE1AFD2A.text	4C16252EAC05FFBD918ECBEDFE1AFD2A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eurysomus soloduchi Minich 1992	<div><p>Eurysomus soloduchi Minich, 1992</p><p>Platysomus sp. Solodukho, 1951: 158-159.</p><p>Platysomus soloduchi Minikh, 1992: 138, table 1.</p><p>Eurysomus soloduchoi Esin, 1993: 129, fig. 1a-c.</p><p>MATERIAL EXAMINED. — Neotype. KFU B-682, complete fish skeleton, poorly preserved; Republic of Tatarstan, Verkhneuslonsky district, Pechishchi locality; middle Permian (Biarmian) Series, Kazanian (Roadian) Stage, Upper Kazanian Substage, Pechishchi Beds, Podboi Member.</p><p>MATERIAL. — Complete fish skeleton and thirty isolated teeth; preserved photographs of the holotype (KFU PP/29).</p><p>DIAGNOSIS. — Deep-bodied fish. The head and pectoral girdle are slightly more than one-third of the standard length. The body is more rectangular than circular. The operculum is high and rectangular, with rounded corners; the ventral margin of the operculum is abruptly convex and sits within the concave margin of the suboperculum; the suboperculum is lower and wider than the operculum; the dorsal margin of the suboperculum is slightly concave anteriorly (J-shaped); one pair of extrascapular bones; the lower jaw is deep and stout; jaws bears one row of molariform teeth with apical cusps; phyllodont tooth plates absent; the majority of bones and scales are ornamented with subvertical cylindrical ridges; the squamation consists of 40 scale rows; ventral and dorsal ridge scales are extended into short spines; pectoral fins are relatively large; pelvic fins are well developed. At the anterior ends of the dorsal and anal fins, the upper and lower margins are angulated. The dorsal and anal fins are moderately (ratio dorsal fin/standard length is 1:5) long-based and reach all the way down to the narrow caudal peduncle.</p><p>DESCRIPTION</p><p>Both the lost holotype and the neotype are not well preserved. In the holotype, dermal bones of the skull roof, cheek, and pectoral girdle are preserved as impressions</p><p>(Figs 3; 4). The boundaries of individual bones of the neotype are almost indistinguishable (Figs 5; 6). The head and pectoral girdle are slightly more than one-third of the standard length, and the body from the posterior border of the cleithrum to the anterior border of the caudal peduncleis slightly longer than deep. The body is more rectangular than circular. The upper and lower margins of the body at the beginning of the unpaired fins are almost straight and only slightly convex (the height of this part of the body increases very slowly from front to back). At the beginning of the dorsal and anal fins, the upper and lower margins form pronounced dorsal and ventral angles, respectively (Figs 5; 6).</p><p>Skull</p><p>The post-temporal is relatively well preserved in the lost holotype, but poorly preserved in the neotype. Only the ventral margin of the post-temporal is not well preserved. There is a clear section of the supratemporal canal preserved on the ventral part of the bone (Fig. 4A, B). The ornament consists of subvertical cylindrical ridges in the lower half and anterior and posterior parts, ridges broken into rows of tubercles in the center and upper part, and chaotically placed wide tubercles in the upper third portion of the bone. The posterior and upper margins are concave. The single extrascapular is rectangular, relatively wide and bears a vertical supratemporal canal. The anterior suture with the postparietal is straight. The ornament consists of sub-horizontal cylindrical ridges in the lower half and randomly distributed tubercles in the upper half. Minikh (1992) noted that there is an extrascapular series of five small, rounded bones (Fig. 4A, B). However, our observations do not confirm this because there is only one extrascapular bone.</p><p>The postparietal is square with rounded corners. The parietal is rectangular (Fig. 4A, B). The postparietal is half the size of the parietal. A horizontal supraorbital canal goes through both bones. The ornament consists of subvertical cylindrical ridges in the anteroventral third and randomly distributed tubercles in the rest of the bone surface. Suture between the parietal and postparietal is straight. The ventral margins of both bones are not well preserved. Two bones preserved ventral to the skull-roof are presumably the dermosphenotic and supratemporotabular. Both bones are heavily damaged, making their true shapes indistinguishable. However, the position and ornamentation of preserved remains/imprints are allowing to identify these bones. The dermosphenotic and supratemporotabular are ornamented with undulating cylindrical ridges. Another heavily damaged bone, presumably the supraorbital, is preserved above the orbit (Fig. 4A, B).</p><p>The opercular series consists of an operculum, suboperculum, and possibly preoperculum (Fig. 4A, B). The operculum is high (approximately two times deeper than wide) and rectangular with rounded corners. The posterior margin is slightly convex. The dorsal and anterior margins of the operculum are not well preserved, so its exact height remains. The ventral margin is strongly convex and sits within the concave margin of the suboperculum. It bears an unornamented area where the suboperculum would have overlapped the operculum. This became observable, apparently, due to the postmortem dislocation of these bones. The ornament consists of long subvertical cylindrical ridges. The suboperculum is large, wider (but two times lower) than the operculum. The anterior and ventral margins are damaged, but overall, the shape of this bone is preserved. The dorsal margin of the suboperculum is slightly concave in its anterior half (J-shaped). The anterior portion of the suboperculum is wider than the posterior portion. The ornament consists of radiating cylindrical ridges in anterior part and parallel to posterior margin sub-horizontal cylindrical ridges in the posterior portion. The radial ridges probably diverged from the center of ossification. Between the operculum and the orbit lies a highly damaged bone that we interpreted as remains of a preoperculum. The ornament consists of subvertical cylindrical ridges. Esin (1993) argued that the suboperculum is much higher than the operculum, which has an almost square shape.We suggest this is a misinterpretation caused by a horizonal crack through the operculum.</p><p>The snout is more poorly preserved than other parts of the skull (Fig. 4A, B). In addition to the heavily damaged maxilla and mandible, only the general outline of an indeterminate bone is apparent around the maxilla/mandible remains. The preserved supraorbital canal indicates that it may be the outline of the nasal bone. The mouth is terminal. The maxilla is damaged and bears only one tooth. The mandible has five teeth. Its lateral surface is ornamented with cylindrical ridges.</p><p>Postcranium</p><p>The endoskeletal pectoral girdle consists of the clavicle,cleithrum, supracleithrum, and postcleithrum. All bones are present in the neotype, but observable only from the inner side (Figs 5; 6A). Therefore, the ornamentation of the outer side remains unknown.The clavicle is a triangular bone ventral to the cheek region. The cleithrum consists of a high and slender dorsal part that extends up to about the middle portion of the operculum and a triangular, sigmoidal curved ventral part. There is a clear embayment on the posterior margin of the ventral portion to accommodate the pectoral fin.The supracleithrum is slender, but its precise shape remains unclear. The postcleithrum is crescentshaped and slender, with a posteriorly directed bony plate on the posterior margin. The bony plate is covered with scales.</p><p>All fins are present in the neotype (Figs 5-7). The pectoral and pelvic fins are relatively well developed. There is no evidence of fulcra associated with the pectoral and pelvic fins. The pectoral fin is quite large but relatively poorly preserved (Figs 6A; 7C). Some individual rays can be distinguished, but their exact number cannot be counted. At the base of the rays, elongated bones have been preserved, which may be radials or elongated basal hemisegments (Fig. 7C). The pelvic fin is well preserved and situated a short distance in front of the ventral angle of the ventral trunk margin (Figs 6C; 7A). There is a fairly large plate at the base of the fin, and several small bones, probably radials, are attached to it (apparently, some of them were lost). The posteriormost bone in the row is much larger and could potentially represent the metapterygial axis, like in Moythomasia Gross, 1950 (Gardiner 1984). Distal radials (like in Polypterus Lacepède, 1803, Molnar et al. 2016) are absent. The basal hemisegments of lepidotrichia are large, and the lepidotrichia themselves divide at the border of the basal and following hemisegments (Fig. 7A, small black arrow). The total number of lepidotrichia reaches nine. There is a large, circular preanal scute between the pectoral and anal fins (Fig. 6C).</p><p>The dorsal fin is not very long based but extends all the way down to the caudal peduncle (Figs 6B, D; 7B). Part of the lepidotrichia has been lost, which makes it impossible to establish their total number. The observed rays do not branch. The caudalmost fin rays are the shortest and the most delicate. Apparently, the radials (baseosts sensu Stensiö 1932) were hourglass shaped (Fig. 7B). The anal fin is very similar to the dorsal fin in terms of shape, but it has a slightly shorter base (Figs 6C, D; 7D). Part of the lepidotrichia is also missing, and the preserved rays indicate that their total number was not less than 40. These preserved distal radialis were also hourglass shaped. Above the distal radials there are several obliquely oriented, hourglass shaped bones (inclined backwards) that are tapered in the middle and expanded at the ends (Fig. 7D). We assume that these are proximal radials (axonosts sensu Stensiö 1932). The bones are not associated with the vertebral column and, apparently, were unpaired (the observer sees only the bones of the right side of the body). Two rows of large radials are characteristic of some early ray-finned fishes, for example, for Pteronisculus White, 1933 (Nielsen 1942). However, the unpaired fins of E. soloduchoi are better compared to those of Bobasatrania groenlandica Stensiö, 1932, and consist of the same elements (Stensiö 1932). Neotype of E. soloduchoi differs from B. groenlandica in the absence of dorsal fin axonosts, but this is due to the poor preservation of the specimen. The caudal fin is heterocercal but equilobate (Figs 5; 6D). Some of the lepidotrichia are damaged, the unpreserved rays indicate that there were at least 35 of them. The fin rays gradually shorten toward the center of the fin and branch distally. The lowermost ray of the ventral lobe is much shorter than the successive rays and have tapered, spine-like distal segments (Fig. 7G). Caudal ridge scales (“fulcra” sensu Zidek 1992) form the ridge of the caudal lobe and have tapered, spine-like distal projections (Figs 6D; 7F). Their exact number cannot be determined due to poor preservation.</p><p>Squamation</p><p>The squamation consists of 40 scale rows between the postcleithrum and the end of the caudal peduncle (Fig. 5). Body rows are nearly vertical, with body scale rows only slightly anteriorly inclined, while rows on caudal peduncle are strongly decline posteriorly.The flank scales are rectangular (Fig. 5), low along the ventral and dorsal margins of the body and caudal peduncle and tall otherwise. Pegs for articulations between scales are triangular, tall and well developed. Antero-dorsal and postero-dorsal corners are not pronounced because they are merged with the very wide base of the dorsal peg. The free field consists of cylindrical, nearly parallel, vertical or subvertical ridges. The ridge scales (Fig. 7E) are triangular in lateral projection and bear presumably ganoin-covered denticles (as indicated by ultrasculpture of thin, vertically stretched microtubercles).</p><p>Dentition</p><p>The teeth of the neotype are partly embedded in the rock, but are better preserved (Fig. 8). The teeth are wide in the lower part and cylindrical in cross section. The maximum width of the tooth is approximately equal to the width of the base. The apex is domed. The apex of the tooth is crowned by a cusp (i.e., acrodin cap), which can be distinguished by translucency relative to the rest of the tooth. The cusp is separated by a sharp angulate inflection. The cusp has the shape of a slightly pointed dome, and together with the tooth forms a compound dome. The surface of the cusp is smooth, but the rest of the tooth bears delicate longitudinal striations. Slightly worn isolated teeth (Fig. 9A) have a slightly pointed cusp, while most of the teeth in the neotype have markedly flattened cusps (Fig. 8B, C), which may indicate some tooth wear. Most of the teeth in the sample are quite heavily worn, and their upper surface is covered with numerous scratches. Some teeth have been worn down to form a flat surface with openings for dentine tubules visible on the surface (Fig. 9B, C). Minikh (1992) noted that the maxilla and the dentary were edentulous, and only the palatine bones bear rod-shaped teeth. However, our observations do not confirm this.</p><p>REMARKS</p><p>The jaws of E. soloduchi are less protruding than in E. macrurus . Eurysomus soloduchi is a much smaller species that also has a smaller caudal fin and narrower caudal peduncle in relation to the body size and the pelvic fin is located much closer to the anal. E. macrurus has two rows of clavate teeth with a flattened grinding surface and constricted neck (King 1850; Young 1866; Schaumberg 1976; Haubold &amp; Schaumberg 1985) and an acrodin cap that is wide and flat, and circumscribed by a fine sulcus (King 1850; Geinitz 1861; Schaumberg 1976: abb. 31; Haubold &amp; Schaumberg 1985: abb. 107), whereas E. soloduchi has teeth that are cylindrical in cross section and crowned by a slightly pointed dome-shaped acrodin cap. Differences in tooth structure appear to reflect slightly different foraging strategies in these species.</p></div>	https://treatment.plazi.org/id/4C16252EAC05FFBD918ECBEDFE1AFD2A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bakaev, Aleksandr S.	Bakaev, Aleksandr S. (2024): Neotype designation for Eurysomus soloduchi Minich, 1992 and evidence of durophagy in the East European Platysomidae (Actinopterygii, Bobasatraniiformes). Comptes Rendus Palevol 23 (30): 465-480, DOI: 10.5852/cr-palevol2024v23a30, URL: https://doi.org/10.5852/cr-palevol2024v23a30
