Thrissops ettlingensis Ebert, 2025, sp. nov.

Thrissops ettlingensis sp. nov. Figs 8, 9, 10, 11, 12, 13, 18 D, 20 A 2010 b Thrissops cf. formosus Agassiz, 1833; Ebert and Kölbl-Ebert: figs 5 a, b. 2013 Thrissops n. sp. Ebert and Kölbl-Ebert: p. 46; figs 4 a, 4 b, 5; tab. 1. 2020 “unbenannte Thrissops Art” Kölbl-Ebert and Ebert: fig. 15 e. 2024 Thrissops n. sp. Ebert: p. 357; figs 12.11 A, B, 12.15, 13.8; tab. 12.1. Holotype. JME -ETT 3345 (Figs 8, 11, 13 A, 18 D), complete specimen in lateral view, 11.6 cm standard length (SL). Type locality. Ettling, Markt Pförring, Bavaria, Germany. Type horizon. From the eigeltingense β horizon of the lower Tithonian (see Tischlinger and Schweigert 2020). Additional material (all from Ettling). Coll. Tischlinger 20 / 4, 20 / 8; JME -ETT 166 (Figs 9 A, 12), 220 (Fig. 9 B), 1360 (Fig. 10 A, B), 4104 a, b (Figs 9 C, 13 C, D). Etymology. The specific epithet in Thrissops ettlingensis refers to the village of Ettling, Markt Pförring, Bavaria, Germany where the specimens were found. Diagnosis. Thrissops reaching 15.5 cm total length (13 cm SL), with the following unique combination of characters (for measurements of specimens and counts of features see Suppl. material 1: table S 1): standard length (SL) to body depth (BD) 26–33 % (average 31 %); 30–31 supraneurals; 49–50 vertebrae (without ural centra); 24–25 ribs anterior of anal fin; 23–25 anal pterygiophores; small teeth (Figs 11, 12, 18 D); curved maxilla (Figs 11, 12, 18 D, 20 A); regular dentition in the lower jaw. Morphological description (for measurements of specimens see Suppl. material 1: table S 1). General features. In Thrissops ettlingensis, the maximum body depth (MD) is 26–33 % (average 31 %) of its standard length (SL), with up to 15.5 cm in total length (13 cm SL). One juvenile specimen of 3.5 cm SL (JME -ETT 1360) is also known from Ettling. The dorsal and the anal fins are in the posterior half of the body, with the dorsal fin origin slightly posterior to the anal fin origin, which is typical for Thrissops and Allothrissops (Nybelin 1964) (for differences to other species see Table 1). Skull and dentition. Cranial morphology. Cranial morphology of Thrissops ettlingensis is best visible in the holotype (JME -ETT 3345 a, Fig. 11) and JME -ETT 166 (Fig. 12), both showing the left side of the cranium. None of the cranial bones shows ornamentation or have serrated posterior borders. Braincase and Ethmoid region. Most bones of the braincase are covered by other bones of the cranium, only the rostrodermethmoid and parts of the palatine, the ethmoid complex and the parasphenoid are visible. A small part of the palatine is visible at the anteriordorsal border of the maxilla ventral to the nasal pit. The lateral ethmoid separates the orbita posteriorly from the nasal capsule anteriorly. The ethmoid complex in Ichthyodectiformes is described in detail in Cavin et al. (2013). A small part of the parasphenoid is visible at the ventral border of the orbita. The rostrodermethmoid is an unpaired bone, at the anterior part of the cranium posterior of the premaxilla. Posteriorly it extends between the paired frontals. Skull roof. The elongated frontals are the largest bones of the skull roof, with the posterior part twice as wide as the anterior part. The anteriormost part of the frontals is covered by the rostrodermethmoid, posteriorly the frontals overlap slightly the parietals. It is unclear if the parietal in Th. ettlingensis is an unpaired ossification median on the scull roof, because only one side of the cranium is visible. The visible parietal at the posteriordorsal border of the frontal, are nearly quadrangular, only about half the size of the extrascapular and probably as large as the pterotics. The pterotic is smaller anteriorly and gradually widens posteriorly, but the exact shape is not clearly visible due to the incomplete preservation of the specimens. There is one large extrascapular and one posttemporal on each side of the cranium. The nasal is a short, tubular, nearly rectangular bone at the posterior border of the nasal pit, with a canal running in its center. Circumorbital series. Antorbitals anterior of the frontals are not recognizable in any of the specimens. There is a total of four thin infraorbitals (io) ventral and posterior of the orbit. The anteriormost two infraorbitals (io 1, io 2) are slender and anteriorly posteriorly elongated. The lacrimal (io 1) extends from the nasal pit to the level of the first third of the orbita. The second infraorbital (subinfraorbital, io 2) nearly went to the posterior border of the orbita. The third infraorbital (io 3 = ventral postinfraorbital), is the largest infraorbital, it is nearly as long as it is deep. This bone is recognizable by postero- and postero-ventrally directed branches of the infraorbital canal. The fourth and last infraorbital (io 4 = dorsal postinfraorbital) is best visible in the holotype JME -ETT 3345 a (Fig. 11). This bone is higher than long and lies on the posterior border of the orbit posterior to the sclerotic ring. A gap in which parts of the hyomandibula are visible separates the two posterior infraorbitals from the preoperculum. The infraorbital sensory canal is well visible in the holotype and JME -ETT 166 (Fig. 11, 12). The autosphenotic is a somehow triangular bone at the posteroventral border of the orbit, but its exact borders are not clearly visible in any of the specimens. Suborbitals and supraorbitals are not recognisable in any of the specimens and probably generally absent. At least two large, broad bones of the sclerotic ring surround the orbita, but these fragile bones are broken and its borders are not everywhere clearly visible. The basal sclerotic bone is a thin, rounded bone in the posterior dorsal part of the orbita. Opercular series. The preopercle is large with a long and slender dorsal part and a broad ventral part which extends anteriorly and posteriorly. It has slightly concave posterior margin; ventrally it has a well-developed posteroventral process. In the ventral part the preopercular canal is well visible. Some extensions of this canal bend ventrally and end in small openings on the surface. The opercle is twice as high as it is wide (antero-posteriorly). Its dorsal border to the posttemporal is convexly curved, whereas its posterior border to the supracleithrum and cleithrum, its ventral border to the subopercle and the anterior border to the preopercle is nearly straight. The subopercle is small, with its anteriormost part with the anteriordorsal process covered by the preopercle. An interopercle is not visible, probably totally overlapped by the preoperculum. Branchiostegal series and gular plate. There are 16 branchiostegal rays on the holotype (Fig. 11). The rays in the anterior half of the series being fine and hair-like. The posterior five rays are wider with the posteriormost being about three times as wide as the ray anterior to it. The anterior hair-like rays end in a point whereas the posterior rays have rounded posterior margin. Anterior to the branchiostegals, between the two dentaries there is a part of a small, thin bone visible, which is interpreted here as a small gular plate. Jaws and suspensorium. The upper jaw consists of maxilla, premaxilla and two supramaxillae. The premaxilla at the anteroventral edge of the upper jaw is broad. On its convexly rounded anteroventral border there are eight to ten small teeth which are about twice as long and wide as the maxillary teeth (best visible in the holotype, Fig. 11). The posteriodorsal part of the premaxillae is covered by the maxilla and the rostrodermethmoid. As in all Ichthyodectiformes the maxilla is long. In Thrissops ettlingensis at least as long as the dentary but not reaching the posterior border of the orbita. Its posterior border to the angular is rounded, covering the anterior part of the quadrate. The anteriormost part of the maxilla, which is covered by the premaxilla and the rostrodermethmoid, bents ventrally, whereas the visible anterior part is nearly straight. The posterior half of the maxilla bends continuously dorsally. Only one row of teeth with 51 small, pointy teeth is visible on the ventral margin of the maxilla of the holotype (Fig. 11). Almost all teeth are of the same length only the posteriormost are slightly smaller. There are two supramaxillae on both sides of the cranium which run along more than half of the posteriodorsal margin of the maxilla. The anterior supramaxilla is slender, half as large as the posterior one and tapers towards the front. The posterior supramaxilla is as long but twice as wide as the anterior one. The posterior supramaxilla has an anteriodorsal process that ends in a point and covers the posterior half of the dorsal margin of the anterior supramaxilla. The maximum height of the posterior supramaxilla, is a little higher the maxilla at its highest point in the centre of the maxilla. The mandible is moderately long, reaching the posterior edge of the orbita. There are 22 small, pointed teeth along the dorsal border of the dentary visible in the holotype (Fig. 11). The dentary teeth are slightly larger than the corresponding maxillary teeth. They are situated in one row and are of approximately the same size all along the whole length of the dentary. The mandibular sensory canal runs from anterior to posterior in the middle of the bone in a small groove. A border between the dentary and the angular is clearly visible at the dorsalmost part of the mandible. Dorsally the angular is covered by the posteriormost part of the maxilla. The quadrate is large, but the articulation to the mandible is covered by the angular. The slender, elongated symplecticum branches off from the posteroventral part of the quadrate and extends posteriordorsally between the quadrate and the preoperculum. Pectoral girdle. The large posttemporal borders the operculum dorsally. Along its ventralmost part, which is twice as broad as the dorsal part, the posttemporal senso