Letovichthys ŠTAMBERG , 2007

Štamberg, Stanislav, 2013, Knowledge Of The Carboniferous And Permian Actinopterygian Fishes Of The Bohemian Massif - 100 Years After Antonín Frič, Acta Musei Nationalis Pragae Series B 69 (3 - 4), pp. 159-182 : 159-160

Genus Letovichthys ŠTAMBERG, 2007

T y p e s p e c i e s: Letovichthys tuberculatus ŠTAMBERG, 2007 .

L o c u s t y p i c u s: Kladoruby “Dolní Pepřík”, near the town Letovice, Blansko district, Czech Republic.

S t r a t u m t y p i c u m: Lubě Horizon, Lower Letovice Formation, Early Permian.

D i a g n o s i s: Body slender-fusiform, head low with moderately pronounced rostral part. Frontal very narrow and long, not in contact with orbit. Length/width ratio is 3.3, interfrontal suture straight, and lateral border of the bone is without any process. Frontals two times longer than the parietals. Interparietal suture half as long as lateral edge of parietal. The fronto-parietal suture is shifted only slightly posteriorly or nearly at the same level as the suture between the dermosphenotic and dermopterotic. The dermosphenotic is triangular, anteroposteriorly elongated, and tapering anteriorly to the nasal. The dermosphenotic carries the infraorbital canal, which probably bends ventrally, and dorso-lateral-anterior canal extends to the anterior extremity of the dermosphenotic. The dermopterotic is rectangular; its posterior margin is at the same level as the posterior termination of the parietal. All bones of the skull roof are ornamented with outstanding closely arranged tubercles or very short ridges. All tubercles and ridges bear fine ridges that are concentrated on their tops. From one to three pairs of extrascapular lateral and one or two pairs of extrascapular medial form a narrow strip between the parietal, dermopterotic and posttemporal. Preoperculum reaches to the dermopterotic and dermosphenotic. Anteroventral border of the preoperculum bends at an angle of 90 degrees, the posterior border of the bone is not inflexed, but only moderately bent. Lower jaw is very strong, and ornamented on ventral half of the lateral surface with prominent mounds of ganoin. Large dorsal region of the lateral surface of the lower jaw is without sculpture. Maxilla with large maxillary plate of trapezoidal form tapers ventroposteriorly to the projection. The length of the maxilla is 1.5 – 2.2 times the length of the maxillary plate, and 3 – 3.3 times the height of the maxillary plate. Premaxilla is present and is probably toothed. Marginal teeth on the jaws are arranged in two rows. Outer row is composed of numerous, small, sharp-pointed teeth. The inner row possesses large conical teeth, three times taller than those in the outer row. They can be less numerous, numbering about 16 teeth per jaw, with large gaps between neighboring teeth, or they are numerous, arranged closely without gaps, with about 40 teeth per jaw. Prearticular provides numerous very small teeth. Hyomandibular with well-developed processus opercularis. Rectangular operculum, 1.8 times higher than long. Suboperculum with sloping dorsal border, anterior border of the bone two times shorter than the posterior one. Oval paired posttemporal, with distinctive ridges longitudinally arranged. Small presupracleithrum present. Distinctive sculpture from long ridges parallel with the posterior border of the bone covers posterodorsal region of the supracleithrum. Pectoral fins with lepidotrichia probably not segmented at their bases. Leading two or three lepidotrichia of the pectoral fins are stout, not segmented along their entire length. Fringing fulcra present on the pelvic and anal fins and on the ventral lobe of the caudal fin. The scales are small, and those on dorsal side of the body are strongly sculptured. Sculpture consists of dorsoventrally arranged ridges, sometimes anastomosing on dorsal two third of the scale, and long ridges along ventral border of the scale. The scales are situated on the dorsal side of the body, but those more ventrally have less numerous simple ridges dorsoventrally arranged, while long ridges along the ventral border of the scale disappear completely.

I n c l u d e d s p e c i e s: Letovichthys multidentatus ŠTAMBERG, 2007 besides the type species Letovichthys tuberculatus ŠTAMBERG, 2007 .