12 research outputs found
Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany)
No full textKonwert, Martin, Stumpf, Sebastian (2017): Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany). Zootaxa 4243 (2): 249-296, DOI: https://doi.org/10.11646/zootaxa.4243.2.
Leptolepis Agassiz 1832
No full textLeptolepis Agassiz, 1832 Type species. Leptolepis coryphaenoides (Bronn, 1830). Content. L. coryphaenoides (Bronn, 1830); L. normandica Nybelin, 1962; L. jaegeri Agassiz, 1832; L. autissiodorensis Sauvage, 1892; L. saltviciensis Simpson, 1855; L. woodwardi Nybelin, 1974, L. nathorsti Woodward, 1900. Geographical distribution. Lower to Middle Jurassic sediments of: Spitsbergen, Svenskøja (Svalbard, Norway); Neudingen, Dormettingen, Holzmaden, Zell, Boll (Baden-Württemberg, Germany); Dobbertin, Grimmen (Mecklenburg-Western Pomerania, Germany); Salzgitter, Schandelah, Hondelage (Lower Saxony, Germany); Le Cain, Curcy (Normandy, France), Dumbleton, Gretton, Ilminster (England, Great Britain); Bergamo (Lombardy, Italy) (data from Wenz 1968; Nybelin 1974; Tintori 1977; this paper). Stratigraphical distribution. Lower Jurassic, lower Toarcian to Middle Jurassic, Callovian.Published as part of Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2) on page 257, DOI: 10.11646/zootaxa.4243.2.2, http://zenodo.org/record/39908
Leptolepidae Pictet 1854
No full textLeptolepidae Pictet, 1854 Content. Leptolepis coryphaenoides (Bronn, 1830); L. normandica Nybelin, 1962; L. jaegeri Agassiz, 1832; L. saltviciensis Simpson, 1855; L. autissiodorensis Sauvage, 1892; L. woodwardi Nybelin, 1974; L. nathorsti Woodward, 1900; Proleptolepis furcata Nybelin, 1974; P. elongata Nybelin, 1974; P. megalops Nybelin, 1974; Longileptolepis wiedenrothi (Arratia & Thies, 2001). Geographical distribution. Lower to Middle Jurassic sediments of: Spitsbergen, Svenskøja (Svalbard, Norway); Neudingen, Holzmaden, Zell, Boll (Baden-Württemberg, Germany); Dobbertin, Grimmen (Mecklenburg-Western Pomerania, Germany); Salzgitter, Schandelah, Hondelage (Lower Saxony, Germany); Le Cain, Curcy (Normandie, France); Dumbleton, Gretton, Ilminster (England, Great Britain); Bergamo (Lombardy, Italy); Quebrada Vaquillas Altas, Quebrada la Carreta (Chile); Antarctic peninsula (Antarctica); Sao Pedro de Muel (Portugal) (data from Wenz 1968; Nybelin 1974; Tintori 1977; Arratia & Thies 2001; Arratia & Hikuroa 2010; Arratia 2015b; Antunes et al. 1981; this paper). Stratigraphical distribution. Lower Jurassic, Sinemurian, Asteroceras obtusum Zone to late Middle Jurassic, Callovian.Published as part of Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2) on page 254, DOI: 10.11646/zootaxa.4243.2.2, http://zenodo.org/record/39908
Leptolepis
No full text<i>Leptolepis</i> sp. 1 <p>Figures 8 A, B; Plate 4E</p> <p> <b>Remark.</b> The herein examined specimens GG 431/4, GG 431/17 and GG 431/18 show anatomical similarities to <i>L</i>. <i>jaegeri</i> concerning the shape of the maxilla, premaxilla and the dentition of these bones. The preopercle and the dentition of the dentary are different to those in the neotype of <i>L</i>. <i>jaegeri</i> (NRM P 6483a, b). We are not yet sure if these differences have to be interpreted as intraspecific variations of <i>L</i>. <i>jaegeri</i> or if the specimens represent another species. We will give a description in a separate contribution.</p>Published as part of <i>Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2)</i> on page 275, DOI: 10.11646/zootaxa.4243.2.2, <a href="http://zenodo.org/record/399081">http://zenodo.org/record/399081</a>
<i>Grimmenichthys ansorgei</i>, gen. et sp. nov. (Teleostei, ‘Pholidophoriformes’), and other ‘pholidophoriform’ fishes from the early Toarcian of Grimmen (Mecklenburg-Western Pomerania, Germany)
No full textRare finds of ‘pholidophoriform’ fishes from the early Toarcian (Early Jurassic) of Grimmen (Mecklenburg-Western Pomerania, Germany) are described. The specimens include two isolated dentaries, an isolated braincase, several isolated scales, and an articulated, but incomplete specimen. The isolated bones are described in open nomenclature, whereas the articulated specimen is assigned to a new genus and species. The new taxon, Grimmenichthys ansorgei, gen. et sp. nov., shows an autapomorphy (notch in anteroventral margin of preopercle present) and some synapomorphies (e.g., five or six infraorbital bones; lepisosteoid-type scales, deeper than long in predorsal region, present) of Pholidophoridae s.s. The abdominal vertebrae of Grimmenichthys ansorgei, gen. et sp. nov., are diplospondylous which is also the case in the pholidophorids Pholidoctenus serianus and Malingichthys nimaiguensis, but the pattern of mineralization of the hemichordacentra is different from the condition in both of these pholidophorid species. http://zoobank.org:urn:lsid:zoobank.org:pub:55B9DFBC-0394-4243-80C2-B55744C156C0 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Konwert, M., and M. K. Hörnig. 2018. Grimmenichthys ansorgei, gen. et sp. nov. (Teleostei, ‘Pholidophoriformes’), and other ‘pholidophoriform’ fishes from the early Toarcian of Grimmen (Mecklenburg-Western Pomerania, Germany). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1451872.</p
Proleptolepis
No full textProleptolepis -like Figure 3, Plate 1C Material. MV 202612, fragmentary head preserved in medial view. Geographical distribution. Former clay pit of Grimmen, Mecklenburg-Western Pomerania, Germany. Stratigraphic distribution. Lower Jurassic, lower Toarcian “Green Series”, Harpoceras falciferum Zone, Harpoceras exaratum Subzone. Description. Opercular series (Fig. 3; Pl. 1C): The opercle, subopercle, propercle, and interopercle are preserved in the specimen. The opercle is poorly preserved. Its anterior margin is formed by a well-ossified ridge. The broad and deep subopercle is very large. The overall size seems to be equal to the size of the opercle, or it was slightly larger. The anterodorsal and anterior margins of the subopercle are straight, whereas the ventral and posterior margins are convex. The dorsal part of the preopercle is not preserved, but its mold allows to evaluate its outline. The bone is formed by a dorsal, vertical oriented, and a ventral, horizontal oriented limb; both limbs form an angle of about 120°. Anteriorly, at the confluence of both limbs there is a broad, convex process. Although the ventral margin of the bone is covered by the interopercle, the exposed part suggests the ventral limb of the preopercle to be very deep. In the posterior margin of the bone, at about the confluence of both limbs, a deep, sharp notch is present. The fragments and the molds interopercle suggest that it was large and triangular. Its length exceeds the length of the ventral limb of the preopercle. The ventral and posterior margins of the bone form an angle of about 90°. Infraorbital 3 and suborbital (Fig. 3; Pl. 1C): Anteriorly to the preopercle, there are fragments of a canal bearing, dermal bone. In order to the large size and the position of these remains, they are identified as belonging to infraorbital 3. Between the posterior margin of infraorbital 3 and the impression of the preopercle, there are two bone fragments. According to their position, these fragments are interpreted as remains of a suborbital bone. Sensory canal system (Fig. 3; Pl. 1C): The infraorbital sensory canal is only known from a single, trifurcated tubule in the remains of infraorbital 3. The preopercular canal runs close to the anterior respectively dorsal margins of the bone. Its canal gives off at least 10 unbranched tubules. Some more might be covered by the interopercle. The dorsal part of the canal gives off a single, posteriorly directed, long tubule. This seems to end at or close to the posterior margin of the preopercle. Two short and thin tubules are present at the confluence of both limbs, an additional short tubule is directed anteriorly. Identification: The shape of the preopercle and the large size of the subopercle prevent an assignment to any species of Leptolepis. A large subopercle is found in Longileptolepis wiedenrothi, Proleptolepis furcata and P. megalops. As described above, MV 202612 bears a deep notch in the posterior margin of the preopercle. A shallow notch is present in Longileptolepis wiedenrothi (Arratia & Thies 2001) and some species of Leptolepis (see below). A deep notch in the posterior margin of the preopercle, similar to the described specimen, is only present in Proleptolepis. Thus, MV 202612 indicates closest morphological resemblance to Proleptolepis. However, given the incomplete nature of the specimen it is here considered as an indeterminate Leptolepidae until more material is available.Published as part of Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2) on page 256, DOI: 10.11646/zootaxa.4243.2.2, http://zenodo.org/record/39908
Leptolepidae
No full textLeptolepidae sp. 1 Figure 2; Plate 1A, B Material. GG 431/5a, b isolated head missing postcranial bones, preserved in part and counterpart. Many of the bones are missing but molds of the bones are preserved on both slaps, showing their outlines and ornamentation. Geographical distribution. Former clay pit of Dobbertin, Mecklenburg-Western Pomerania, Germany. Stratigraphical distribution. Lower Jurassic, lower Toarcian “Green Series”, Harpoceras falciferum Zone. Description. Cranial bones (Fig. 2; Pl. 1B): The parietal is incompletely preserved, but the impressions of the bone on GG 431/5a and b show that the anterior portion of the bone was thin and elongate. The posterior part is broad with an undulating posterior margin. The surface of the bone is ornamented with several fine grooves. The postparietal is not preserved. The pterotic is somewhat L-shaped with a broad ventral and a thin dorsal limb, the latter is mainly formed by a heavily ossified bony ridge. Some short vertical grooves are present on the surface of the bone, the most posterior one, that is deeper and broader than the previous ones, seems to be the middle pit line. A short section of the parasphenoid is preserved in the specimen, it is thin and heavily ossified. The posterior margin of the extrascapula is damaged, but the impression of this bone on GG 431/5b shows that it was semicircular, with a straight anterior margin. Upper and lower jaws (Fig. 2; Pl. 1B): The jaws are only known from impressions on the rock. The maxilla is long and slightly convex, at least its anterior part must had been ornamented with longitudinal grooves and ridges. The impressions on GG 431/5b indicate the presence of teeth at least in the posterior part of the maxilla, their size remains unknown. Two supramaxillae are present. They are placed dorsal to the maxilla. The posterior supramaxilla bears a well marked, spine-like anterodorsal process. According to the impressions, both must had been covered with a strong ornamentation of longitudinal grooves and ridges. The molds of the dentary and angular are uninformative. Circumorbital bones (Fig. 2; Pl. 1A): The bones of the circumorbital series are known from impressions of the supraorbital and the left and right infraorbital 1. The dermosphenotic (Fig. 2; Pl. 4B, E) is preserved in GG 431/5a, as well as its impression in GG 431/5b. The supraorbital is elongate with a sharp anterior tip. Its medial margin is sharply angled along its entire length. The possible presence of a posterior supraorbital is unknown. The infraorbital bone 1 was large and broad, with its anterior portion deeper than the posterior. The dermosphenotic is very large for basal teleosts (about 10% of head length), it is somewhat triangular and expands in anterodorsal direction. Opercular bones and branchiostegal rays (Fig. 2; Pl. 1B): The opercular series consists of opercle, subopercle, preopercle; the interopercle was not observed. The opercle is the largest bone of the series, it bears a strongly ossified ridge at its anterior margin. The articulation with the subopercle is oblique. Some irregular shaped grooves are present on the surface of the bone. The subopercle is about as half as deep as the opercle and slightly broader. Its ventral and posteroventral margins are convex. The preopercle consists of a long dorsal and a ventral limb, both forming an angle of 110°. The dorsalmost part of the preopercle is only formed by the bony tube of the preopercular sensory canal. There is a well-marked notch in the posterior margin, and a small process in the anterior margin. Three incompletely preserved, plate-like branchiostegal rays are present ventral to the opercular bones. Sensory canal system (Fig. 2; Pl. 1A, B): All preserved sensory canals are bone enclosed. The preserved part of the supraorbital canal runs along the parietal and forms a slight curve posterior to the orbit. The supraorbital canal ends at the posterior margin of the parietal. The canal probably continues on the postparietal. The canal does not give off any tubules, but four pores are observed. The infraorbital canal is positioned near the dorsal margin of infraorbital 1, at least five tubules are present in this bone. These are long and thin, nearly reaching the ventral margin of infraorbital 1. The infraorbital canal ends at the anterior margin of the dermosphenotic. On the dermosphenotic, the infraorbital canal gives off four tubules, all are directed dorsally, ending close to the dorsal margin of the bone. The infraorbital sensory canal is posteriorly continuous with the otic canal. The otic canal runs along the dorsolateral margin of the pterotic. This canal does not have tubules but two pores are present. The supratemporal canal runs near the anterior margin of the extrascapula, it gives off at least five long tubules that probably reached the posterior margin of the extrascapula. A short part of the middle pit line is probably present in the posterior part of the pterotic. The preopercular canal runs near the anterodorsal margin of the ventral limb of the preopercle, and along the center of the dorsal limb. At least eight tubules are present in the ventral limb of the preopercle, their length increases in posterior direction. They end near the ventral respectively posterior margin of the preopercle. One long tubule was observed in the ventral portion of the dorsal limb of the preopercle. A single pore is present in the dorsal portion of the preopercular canal. Identification: Although poorly preserved and lacking the postcranial skeleton, GG 431/5a, b can be assigned to Leptolepidae based on the presence of two relatively large supramaxillae that are placed at the dorsal margin of the maxilla and the L-shaped preopercle. The specimen cannot be assigned to any existing species of Leptolepidae, since the undulating posterior margin of the parietal, the L-shaped pterotic, and the number of tubules in the infraorbital canal in the dermosphenotic seem to be unique among leptolepids.Published as part of Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2) on pages 254-256, DOI: 10.11646/zootaxa.4243.2.2, http://zenodo.org/record/39908
Leptolepis coryphaenoides Bronn 1830
No full textLeptolepis coryphaenoides (Bronn, 1830) Figures 4 A, B, 6; Plates 2A–C, 3A, B Synonyms: Cyprinus coryphaenoides Bronn, 1830: pl. 1. Leptolepis Bronnii Agassiz, 1832: p. 146. Leptolepis bronnii Quenstedt, 1858: pl. 33 figs. 8–11. Leptolepis bronni Rayner, 1937 (in part): figs. 1–14. Leptolepis coryphaenoides Nybelin, 1962: fig. 1A. Leptolepis coryphaenoides Nybelin, 1963: fig. 9. Leptolepis coryphaenoides Wenz, 1968 (in part): figs. 79–107, pls. XL–XLVIII. Leptolepis coryphaenoides Patterson, 1968 (in part): figs. 9 A–C. Leptolepis coryphaenoides Nybelin, 1974: figs. 4A–B; 5A–K; 6A–L; 7D–G; 8; pls. VI–X; XI, figs. 1, 4–5. Leptolepis coryphaenoides Patterson, 1975 (in part): figs. 58, 89–91, 127, 128A, 132B, 144. Leptolepis coryphaenoides Taverne, 1975: fig. 1. Leptolepis coryphaenoides Nybelin, 1976: pl. 1, fig. 4–5. Leptolepis coryphaeniodes Tintori, 1977: figs. 1–4. Leptolepis coryphaenoides Patterson & Rosen, 1977: figs. 32B–C, 33C. Leptolepis coryphaenoides Schultze & Arratia, 1989: fig. 6A. Leptolepis coryphaenoides Arratia & Schultze, 1990: fig. 10A–E. Leptolepis coryphaenoides Arratia, 1994: pl. 7 figs. A–B. Leptolepis coryphaenoides Wild, 1994: fig. 85. Leptolepis coryphaenoides Arratia & Lambers, 1996: fig. 14C. Leptolepis coryphaenoides Arratia, 1996a: fig. 1D. Leptolepis coryphaenoides Arratia, 1996b: figs. 5A, 6B. Leptolepis coryphaenoides Arratia, 1997: figs. 76A, B, 82A, 83B, 88B, 89A–C, 90A. Leptolepis coryphaenoides Delsate, 1997: pl. 1, 3A–B. Leptolepis coryphaenoides Arratia, 1999: fig. 13. Leptolepis coryphaenoides Kriwet, 2001: fig. 4.7H. Leptolepis normandica Arratia & Thies, 2001: fig. 12B. Leptolepis coryphaenoides Arratia & Thies, 2001: fig. 12D. Leptolepis coryphaenoides Bean, 2006: figs. 9H–I, 19A. Leptolepis normandica Bean, 2006: fig. 18A. Leptolepis coryphaenoides Arratia & Herzog, 2007: fig. 7C. Leptolepis coryphaenoides Arratia, 2008: fig. 7B, 22. Leptolepis coryphaenoides Arratia, 2009: fig. 14A. Leptolepis coryphaenoides Arratia & Hikuroa, 2010: figs. 7A–D. Leptolepis coryphaenoides Arratia, 2013: figs. 97D, 99A, 100A–B. Leptolepis coryphaenoides Schultze & Arratia, 2013: figs. 5B, 9A, B, 21B. Leptolepis coryphaenoides Arratia & Schultze, 2015: fig. 768A. Leptolepis coryphaenoides Arratia, 2015: figs. 4A, C, 10C, 11D, 15C. Material. GG 431/3 slightly disarticulated, incomplete head, from Dobbertin; GG 431/7 subadult, almost complete specimen, missing most of the caudal fin, from Grimmen; NRM P 6091 (cast of MNH P. 23834) fragmentary head, from Dobbertin; GG 431/19 isolated head with pectoral girdle, from Grimmen; GG 431/20 incomplete head, from Dobbertin. Geographical distribution. Neudingen, Holzmaden, Zell, Boll (Baden-Württemberg, Germany); Dobbertin, Grimmen (Mecklenburg-Western Pomerania, Germany); Curcy (Normandy, France), Dumbleton, Gretton, Ilminster (England, Great Britain); Bergamo (Lombardy, Italy) (data from Wenz 1968; Tintori 1977; Nybelin 1974; this paper). Stratigraphical distribution. Lower Jurassic, Toarcian, at least Harpoceras falciferum Zone. Description. Cranial bones (Figs. 4 A, B; Pl. 2A): A short part of the mesethmoid was observed in GG 431/7, most of it is covered by infraorbital 1. The parietals form most of the skull roof. They are poorly preserved in GG 431/7 but the remnants show that they were narrow anteriorly but broader in its posterior portion. The postparietals are not preserved. In GG 431/7 the pterotic is subrectangular, with a smooth surface. The pit lines were not observed. The extrascapula seems to be semicircular, with a straight anterior margin. Upper jaw (Figs. 4 A, B, 5; Pls. 2A, 3A, B): The upper jaw consists of maxilla, premaxilla and two supramaxillae. The triangular premaxilla is very small and elongate, with the ascending process being low and narrow. A single row of very small teeth is present along the oral margin of the premaxilla. The maxilla is the largest bone of the upper jaw. It is moderately long and deep. Its posterior margin reaches the center of the quadrate. The ventral margin is convex, especially its posteroventral margin shows a strong curvature. A single row of miniscule teeth is present on the ventral margin of the maxilla. A well-ossified ridge is present along the lateral margin of the bone. In GG 431/3 several small longitudinal grooves are present on the lateral surface of the maxilla. These were not observed in GG 431/7 but this might due to the fact that GG 431/7 is a subadult specimen and thus, the bone might not be fully developed. Most of the dorsal margin of the maxilla is covered by the supramaxillae. The anterior supramaxilla is elongate, with a sharp anterior tip. A low ridge is present along the lateral margin of the bone. The main body of the posterior supramaxilla is somewhat triangular in GG 431/7 but ovoid in GG 431/3. A long, spine-like anterior process emerges from about the center of the bone. The anterior tip of the process is covered by the first infraorbital in both specimens, so its length is unknown. The posterior supramaxilla shows an ornamentation of several grooves, running parallel to the dorsal and ventral margins of the bone. Lower jaw (Figs. 4 A, B; Pl. 3A): Most of the lower jaw is covered by the maxilla in the examined specimens. The dentary forms most of the ventral margin of the lower jaw. The oral margin ascends with an angle of about 40° in respect to the ventral margin of the dentary. Two very small teeth are preserved on the dentary of GG 431/7. The ventral margin of the dentary is slightly convex and the mandibular sensory canal runs close the ventral margin of the bone. Posterodorsally, the dentary articulates with the angular. The exposed part of the angular shows a distinct ornamentation of grooves and ridges. Circumorbital bones (Figs. 4 A, B, 5; Pl. 2C): The circumorbital series is incomplete in all examined specimens. The large and elongate infraorbital 1 is subtriangular, with its anterior margin deeper than the posterior margin. Infraorbital 2 is very thin, mainly carrying the infraorbital sensory canal. It is slightly shorter than infraorbital 1. Infraorbital 3 is the largest bone of the series. It is subrectangular with a concave anteroventral and convex dorsal and posterior margins. Infraorbitals 4 and 5 are preserved in NRM P 6091. Both are of equal size and shape. They are small and subrectangular. The ventral part of the dermosphenotic is preserved in NRM P 6091 but its exact shape remains unknown. A single suborbital is present between infraorbitals 3 to 5, dermosphenotic, the preopercle and the opercle. It is elongate and bears a well-marked notch in its posterior margin. The ventral part of the thin and delicate anterior sclerotic bone is preserved in GG 431/7. The anterior part of the anterior supraorbital was observed in GG 431/7. It is thin and elongate. A very small, poorly ossified bone lies laterally to the anterodorsal tip of infraorbital 1 and the anterior tip of the parietal of GG 431/7, which might be a remnant of the antorbital. Hyoid- and palatoquadrate arches (Figs. 4 A, B; Pl. 2A): The dorsal part of the hyomandibula is exposed in GG 431/7 and the complete bone in GG 431/3. Anteriorly, it bears a thin lamella, and well-marked opercular and preopercular processes posteriorly. The main body of the quadrate is triangular. It bears a well-defined condyle for the articulation with the lower jaw. The posteroventral process of the quadrate is elongated; its posterior part is broken in GG 431/3 and covered by the preopercle in GG 431/7. Thus, its length remains unknown, but it is at least as long as the main body of the quadrate. The symplectic was not observed. The ventral part of the metapterygoid is exposed in GG 431/7. Its dorsal portion is covered by infraorbital 3 and its ventral margin is less broad than its dorsal part, as well as the dorsal part of the quadrate. An elongate, chondral bone lies ventrally to the preopercle in GG 431/7. This bone was identified as posterior ceratohyal. The number of the branchiostegal rays remains unknown due to poor preservation, but the more posterior ones seem to be longer and much broader than the anterior ones. Opercular bones (Figs. 4 A, B, 5; Pl. 2A–C): From the opercular series the opercle, subopercle, preopercle, and interopercle are preserved in the specimens. A suprapreopercle (see Nybelin 1962, 1974) is absent in specimen GG 431/7. The condition remains unknown in the other specimens. The opercle is the largest bone of the series. A well ossified ridge is present along its anterior margin. Several fine growth lines are running parallel to the ventral posterior and dorsal margins of the bone. The anterior, ventral and posterior margins of the bone are straight, whereas the dorsal margin is convex. Contrary to the descriptions of Nybelin (1962, 1974), the anterior and posterior margins are not parallel. This is also true for specimen NRM P 6091 (MNH P 23834 in Nybelin 1974) which was assigned to L. coryphaenoides. The subopercle is slightly broader than the opercle but less deep. Several fine growth-lines are present parallel to the ventral and posterior margins of the bone. The preopercle is L-shaped. The ventral and dorsal limbs form an angle of a 110° with each other. The dorsal-most part of the dorsal limb of the preopercle is well preserved in GG 431/7. It seems to be only formed by the tube-like ossification of the preopercular sensory canal, and reaches the otic sensory canal dorsally. In GG 431/3, there is an indistinct notch in the posterior margin of the preopercle. Most of the interopercle is covered by the preopercle in both specimens, so not much is known about this bone. Sensory canal system (Figs. 4 A, B, 5; Pl. 2A–C): Only the cephalic sensory canals are known. The trunk canal is not preserved in the examined specimens. All sensory canals are running in tube-like ossifications. A short, poorly preserved part of the supraorbital canal is preserved on the posterior part of the parietal of GG 431/7. Its shape remains unknown. The infraorbital canal runs along the center of infraorbital 1. The canal is not preserved in GG 431/3 but impressions on the surface of the bone indicate the presence of at least four tubules, which seem to end close to the ventral margin of the infraorbital 1. The canal continues in the dorsal margin of infraorbital 2, no tubules were observed. On infraorbital 3, the canal runs near the anterior margin of the bone. It gives off two to four tubules which end at about the center of the bone. These are not branched in the juvenile specimen GG 431/7, but strongly branched in NRM P 6091 and GG 431/19. In NRM P 6091 and GG 431/19, the canal continues close to the anterior margins of infraorbitals 4 and 5. The canal gives off one to two tubules in infraorbital 4 and one in in infraorbital 5. All tubules in infraorbitals 4 and 5 are unbranched, posteriorly directed and close to the posterior margins of the respective bones. The canal on the dermosphenotic is only known from NRM P 6091. In this bone the canal seems to trifurcate. The anterior, dorsal directed part of the canal is undoubtely the anterodorsal branch of the canal. One of the posteriorly, respectively posterodorsally directed “branches” must be a tubule, the other the true posterior branch. A decision cannot be made on the basis of specimen NRM P 6091 because of the defective state of the dermosphenotic. Nybelin (1974:40) interpreted the ventral one as a posterior directed tubule, since he observed an equivalent tubule in another specimen (BMNH 19642). Thus, we follow Nybelin’s interpretation. The mandibular canal is well preserved in GG 431/3. It runs near the ventral margin of the dentary. Three pores are present on the ventral margin of the canal. The canal continues in the ventral part of the angular, the posterior opening is not visible. It is probably placed at the medial side of the bone. The preopercular canal runs close to the dorsal/anterior margin of the preopercle. In GG 431/3 it gives off at least 11 tubules (on the left preopercle), some of them are very broad and at least six of them are branched up to four times. The very broad tubules might be the result of fusion of adjacent tubules. All tubules end close to the ventral or posterior margin of the preopercle. In GG 431/7 the preopercular canal gives off 10 tubules, only two of them are branched. The preopercular canal reaches the otic canal dorsally. The otic canal runs along the dorsolateral margin of the pterotic, a single, dorsally directed, short tubule is present. Posteriorly, the otic canal is continuous with the supraoccipital canal. This runs close to the anterior margin of the extrascapula. The number of tubules and the continuation with the posttemporal canal is unknown because of poor preservation. The canals in the posttemporal and supracleithrum are not preserved. Vertebral column and associated bones (Pl. 2A): The following description is based on GG 431/7, a subadult specimen. Bones of the vertebral column can change their shape and often fuse with other bones during ontogeny. For descriptions of adult individuals of Leptolepis see e.g., Rayner (1937), Wenz (1968), Nybelin (1962, 1974), Arratia (1991, 1997), and Arratia & Hikuroa (2010). The total number of vertebrae, as well as the number of abdominal and caudal vertebrae are unknown, because the anteriormost vertebrae are covered by the opercle, others are covered by scales. The autocentra are slightly longer than broad, each being slightly constricted in its middle part. Their surface is smooth, without any ornamentation. The parapophyses are fused to their respective centrum, they are subtriangular in shape and are as long as their centra. Both halves of the abdominal neural spines are unfused but are fused in the caudal region. The ribs are thin, at least the anterior ribs seem to reach the ventral margin of the abdomen. Thin, elongate epineural processes are associated with the anterior abdominal neural arches. Epipleural bones seem to be absent. All neural arches seem to be unfused with their respective centrum in GG 431/7. Arratia (1991, 1997) described the abdominal neural arches as to be unfused, but the caudal neural arches as fused to their centra in L. coryphaenoides. Therefore, the herein observed unfused caudal neural arches of GG 431/7 are interpreted as an ontogenetic condition. The last six neural spines and the last five hemal spines are distally expanded. The neural spines are thin, their length remain unknown. Pectoral girdle and fin (Figs. 4 A, 5; Pl. 2A): The pectoral girdle is complete in GG 431/7, but many of the bones are poorly preserved. Most of the posttemporal is covered by the opercle, so its shape is unknown. This is also true for the supracleithrum that seems to be elongate. The dorsal limb of the cleithrum is covered by the subopercle, the ventral limb is directed anteroventrally. Its anterior tip and its posterior margin are bent in medial direction. Several fine grooves run parallel to the margins of the cleithrum, which seem to be growth lines. Postcleithrum 1 is an elongate bone, that seems to articulate with the supracleithrum dorsally and overlaps the postcleitrum 2 ventrally. Postcleithrum 2 is broad and seems to be triangular. The dorsal part of postcleithrum 3 is covered by the left pectoral fin. Its ventral part is triangular. The pectoral fin is located close to the ventral margin of the body. The following description is based on the right pectoral fin of GG 431/7. Sixteen pectoral fin rays are present. Most of them are segmented and branched in their distal portions. Two, maybe three small, elongate scales seem to be associated with the last pectoral fin ray. There are four poorly preserved proximal radials. Three are elongate, the fourth is short and about twice as broad as the others. The anterior part of the coracoid is narrow and elongate. Anteriorly it reaches the anteroventral tip of the cleithrum. The posterior part of the coracoid is about as twice as broad as the anterior portion. A small part of the scapula is exposed in GG 431/7, but most of it is covered by the cleithrum, so its shape remains unknown. Pelvic girdle and fin (Pl. 2A): The pelvic fin is placed at about 50% of standard length. The basipterygium is triangular, with a strongly ossified ridge along its lateral edge. Eleven fin rays plus an elongate pelvic splint are present. The distal portions of the pelvic fins are poorly preserved, but at least some of the lepidotrichia are segmented distally. Dorsal and anal fin (Pl. 2A): Both, the dorsal and anal fins are poorly preserved. The dorsal fin consists of at least 11 fin rays. The number of precurrent rays is unknown. At least ten fin rays are present in the anal fin, the first three are precurrent rays. Fulcra are absent in the dorsal and anal fins. Squamation (Pl. 2A): Several comparatively large cycloid scales are preserved in GG 431/7. Their shape is circular in the dorsal part of the abdominal region, but some scales in the ventral part of the abdomen show an oval outline. However, all scales show complete circuli. Remark: Nybelin (1974: pl. IX, fig. 3) figured a cast of a fragmentary head of a L. coryphaenoides from the Dobbertin Lagerstätte with the collection number MNH P 23834. This cast was found in the collection of the Naturhistoriska Riksmuseet in Stockholm, but with the different collection number NRM P 6091. The labels indicate that the collection number MNH P 23834 refers to the original specimen. Identification: The above described specimens share the presence of branched tubules in the preopercular canal. Nybelin (1974) listed three species of Leptolepis which possess branched tubules in the preopercular sensory canal, L. coryphaenoides (Bronn, 1830), L. saltviciensis Simpson, 1855 and L. autissiodorensis Sauvage, 1892. Nybelin (1974) also points out that L. saltviciensis might represents juvenile stages of L. autissiodorensis . The preopercles of L. saltviciensis and L. autissiodorensis are almost equal in shape. They are less broad and more crescentic than in L. coryphaenoides. Furthermore, the tubules in the preopercular canal are shorter, the number of tubules is higher and fewer branched tubules are present in L. saltviciensis and L. autissiodorenis. The herein described specimens GG 431/3, GG 431/19, GG 431/20 and NRM P 6091 have relatively broad preopercles and relatively low numbers of tubules in the preopercular canal. Therefore, they are assigned to L. coryphaenoides. This assignment is also supported by the presence of miniscule teeth on the maxilla and premaxilla, as well as the presence of a small premaxilla in GG 431/3, as described in L. coryphaenoides by Nybelin (1974). Specimen GG 431/7 shows a comparatively narrow preopercle, as described in L. saltviciensis and L. autissiodorensis (Nybelin 1974). Otherwise, GG 431/7 is considered as a juvenile and the preopercle might not be fully developed. The specimen differs to L. autissiodorensis in the low number of tubules in the preopercular canal of 10 (more than 22 in L. autissiodorensis). The miniscule teeth on maxilla, premaxilla and dentary, as well as the small premaxilla of GG 431/7 are consistent with referral to L. coryphaenoides. Thus, GG 431/7 is also assigned to L. coryphaenoides.Published as part of Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2) on pages 258-262, DOI: 10.11646/zootaxa.4243.2.2, http://zenodo.org/record/39908
Contributions to the Taxonomy, Diversity and Palaeobiogeography of certain basal Teleostei (Osteichthyes, Actinopterygii) from the Early and Late Jurassic of Central Europe
No full textCertain basal Teleostei from the Early Jurassic of Mecklenburg-Western Pomerania (Germany) and the Late Jurassic of the Franconian Alb (Bavaria, Germany), the Swabian Alb (Baden-Württemberg, Germany) and the western Jura-Mountains (Ain, France) are described. The present doctoral dissertation includes four studies, dealing with representatives of “Pholidophoriformes”, Leptolepidae and Orthogonikleithridae. These studies include anatomical descriptions of new taxa and reviews of poorly known fishes. Furthermore, the stratigraphic and palaeobiogeographical distributions of the examined taxa are discussed.Diverse basale Teleostei dem Unterjura von Mecklenburg-Vorpommern (Deutschland) und dem Oberjura der Fränkischen Alb (Bayern, Deutschland), der Schwäbischen Alb (Baden-Württemberg, Deutschland) und dem westlichen Jura-Gebirge (Ain, Frankreich) werden beschrieben. Die Dissertation beinhaltet vier Publikationen. In diesen werden Fische der Taxa „Pholidophoriformes“, Leptolepidae und Orthogonikleithridae beschrieben. Die Studien beinhalten anatomische Beschreibungen neuer Taxa und Reviews von wenig bekannten Fischen. Weiterhin wird die stratigraphische und paläobiogeografische Verbreitung der untersuchten Taxa diskutiert
Leptolepis normandica Nybelin 1962
No full text<i>Leptolepis normandica</i> Nybelin, 1962 <p>Figure 6; Plates 1E, 2D, 3C</p> <p>Synonyms:</p> <p> <i>Leptolepis concentricus</i> Egerton, 1849 (in part): p.35.</p> <p> <i>Leptolepis pachystetus</i> Sauvage, 1874: pl. VII, figs. 2, 3. <i>Leptolepis bronni</i> Woodward, 1895: p. 504.</p> <p> <i>Leptolepis normandica</i> Nybelin, 1962: fig. 1B.</p> <p> <i>Leptolepis normandica</i> Nybelin, 1963: fig. 10.</p> <p> <i>Leptolepis coryphaenoides</i> Wenz, 1968 (in part): figs. 91, 92B, 94A, pl. XLII, XLIII fig. C. <i>Leptolepis normandica</i> Nybelin, 1974: figs. 1A, B; 2; 3 A–C; 7A–C; pls. I–IV; V figs. 1–5; IX figs. 2, 3; XXX fig. 1. <i>Leptolepis normandica</i> Nybelin, 1976: pl. 1, fig 3.</p> <p> <i>Leptolepis normandica</i> Delsate, 1997: figs. 1–5; pl. 1, figs. 1, 4A–C; pl. 2, figs. 5–9. <i>Leptolepis normandica</i> Arratia, 1984: fig. 7E.</p> <p> <i>Leptolepis coryphaenoides</i> Arratia & Thies, 2001: fig. 12C. <i>Leptolepis normandica</i> Bean, 2006: figs. 9E–G.</p> <p> <i>Leptolepis coryphaenoides</i> Bean, 2006: fig 18B.</p> <p> <i>Leptolepis bronni</i> Ansorge & Obst, 2015: fig. 15B.</p> <p> <b>Material.</b> GG 431/2a, b, articulated head with pectoral girdle and few abdominal vertebrae, preserved in part and counterpart. The specimen is associated with four insect wings, including the holotypes of <i>Protorhyphus stigmaticus</i> Handlirsch, 1920 and <i>Parablattula reticulata</i> Handlirsch, 1920.</p> <p> <b>Geographical distribution.</b> Curcy, May (Normandy, France); Dumbleton, Alderton (Gloucestershire, England); Dobbertin (Mecklenburg-Western Pomerania, Germany); Barscharage (Luxembourg);?Holzmaden (Baden-Württemberg, Germany) (data from Wenz 1968; Nybelin 1962, 1974; Delsate 1997; this paper).</p> <p> <b>Stratigraphical distribution.</b> Lower Jurassic, Toarcian, at least <i>Harpoceras falciferum</i> Zone.</p> <p> <b>Description.</b> Cranial bones (Fig. 6; Pl. 1E): Most of the cranial bones are poorly or not preserved. Most of the cranial roof is formed by the parietal. It is narrow and elongate in its anterior portion. The posterior portion is damaged. It seems to have been much broader than the anterior part. Anteriorly, the parietal articulates with the mesethmoid. Remnants of the postparietal, pterotic and endocranial bones are preserved but are uninformative. The mesethmoid is short, but the lateral wing is large. It extends in anterolateral and posterolateral directions. The posterior part of the lateral wing is covered by infraorbital 1, so its posterior length is unknown. The nasal bone lies slightly dislocated below the supraorbital. The exposed part of this bone is its posterior portion, which is thin and tube-like, mainly carrying the supraorbital sensory canal. The lateral ethmoid is narrow, elongate, and poorly ossified.</p> <p>Upper jaw (Fig. 6; Pl. 3 C): The upper jaw consists of premaxilla, maxilla and two supramaxillae. The premaxilla is small. It bears a well marked, broad ascending process. A single row of at least eleven, long, but very narrow teeth are present on the oral margin of the premaxilla. The maxilla is the largest bone of the upper jaw. It is long, reaching the posterodorsal margin of the quadrate. The bone is convex ventrally and concave dorsally. A well ossified ridge is present along the lateral margin of the bone. An elongate groove is present on the lateral surface, running parallel to the ridge. Some short grooves are running diagonal to the dorsally and ventral margins of the maxilla at about the center of the bone. The dorsal margin of the maxilla bears an elongate surface for the articulation of the supramaxillae. A single row of several small, needle-like teeth is present along the ventral margin of the maxilla. Each tooth is associated with a small groove. The ventral portions of both supramaxillae are broken and their dorsal margins are covered by infraorbital bones. Thus, the exact shapes of both bones are unknown. The anterior supramaxilla seems to have been elongated, with a sharp anterior tip. The remaining part of the posterior supramaxilla indicates a more or less trapezoidal shape, an anterior process seems to arise from the anteroventral portion of the bone and extands anterodorsally. Its length remains unknown. The surface of the posterior supramaxilla is strongly ornamented. The ornamentation consists of several grooves, running more or less parallel to the ventral margin of the bone and some low tubercles.</p> <p>Lower jaw (Fig. 6; Pl. 3C): The lower jaw is formed laterally by the dentary and angular. Most of both bones is covered by bones of the upper jaw. Most of the ventral margin of the lower jaw is formed by the dentary. The oral margin ascends with an angle of about 30° in respect to the ventral margin of the bone. Four very small teeth were observed on the oral margin. The exposed part of the angular is poorly preserved in the specimen, so not much is known about it.</p> <p> Palatoquadrate and hyoid arches (Fig. 6): The quadrate and a small portion of the entopterygoid are the only exposed bones of the palatoquadrate arch in the specimen. The main body of the quadrate seems to be triangular, as in the other species of <i>Leptolepis</i>. The posteroventral process of the quadrate is longer than the main body, but its posterior part is covered by the preopercle, so its length remains unknown. Some poorly preserved branchiostegals are present ventral to the interopercle, these seem to be elongate and laterally flattened.</p> <p>Orbital bones (Fig. 6; Pl. 1E): The orbital bones are nearly completely preserved, lacking only the posterior supraorbital, the dermosphenotic, and the antorbital. The anterior portion of the anterior supraorbital is preserved in the specimen. It shows a sharp anterior tip and is sharp angled along its lateral margin. The second supraorbital is not preserved. Both sclerotics are preserved. Both are semicircular shaped, and at least the posterior is very broad. They have probably surrounded the eye completely. Infraorbital 1 is subrectangular, with its anterior part being deeper than the posterior margin. Infraorbital 2 is about as long as infraorbital 1, but thin, just a little bit broader than the infraorbital sensory canal. Infraorbital 3 is the largest bone of the infraorbital series. Posteriorly, it reaches the preopercle. It is convex at its ventral and concave at its posterior margins. The dorsal margin of infraorbital 3 is partly overlapped by infraorbital 4. Infraorbital 4 is subrectangular, with a convex ventral margin, which overlaps infraorbital 3. The ventral margin of infraorbital 5 is straight, and as broad as the dorsal margin of infraorbital 4. The bone narrows in dorsal direction. The dorsal margin of the bone is not preserved. One suborbital is present whereas an “accessory” suborbital (see Nybelin 1974) is absent. The bone covers the space between the infraorbitals and the opercle and preopercle. The anterior margin of the bone is covered by infraorbitals 3 to 5. The posterior margin of the suborbital bears a distinct notch. A small notch is also present in the dorsal margin, probably for the passage of the preopercular sensory canal.</p> <p>Opercular bones (Fig. 6; Pl. 1E): The opercular series consists of opercle, subopercle, preopercle and interopercle. The opercle is the largest bone of the series. Its anterior, ventral and posterior margins are straight, but it is convex and bent in medial direction dorsally. Some fine growth lines were observed. The subopercle is about as half as deep as the opercle, but slightly broader. Its posteroventral margin is convex. The preopercle is L-shaped, with a long dorsal and a shorter ventral limb, both form an angle of about 110°. The posterior margin of the preopercle shows a vague notch. In the anterior margin, near the confluence of both limbs, the preopercle bears an anterior process. A suprapreopercle, as described by Nybelin (1974), was not observed. It is either absent or completely covered by the suborbital. Most of the interopercle is covered by the preopercle, so its exact shape is unknown. Its ventral margin is as long as the ventral limb of the preopercle.</p> <p>Sensory canal system (Fig. 6; Pl. 2D): The sensory canal system is known from the mandibular, preopercular, infraorbital, and a very short portion of the supraorbital canal. All preserved parts are enclosed by bone. All tubules are unbranched. The mandibular canal runs close to the ventral margin of the dentary. The canal is poorly preserved and does not allow a proper description. The preopercular canal runs close to the dorsal margin of the ventral limb and along the center of the dorsal limb of the preopercle. It gives off twelve tubules, nine of them are present in the ventral limb. These tubule increase in length posteriorly, and point in posteroventral direction. The tubules in the ventral limb end close to the ventral margin of the bone or reach the margin. At the confluence of dorsal and ventral limb, two tubules, pointing in posterior and posterventral directions are present. These are much shorter than the preceding ones and do not reach the posterior margin of the preopercle. A very short, anteriorly directed tubule is also present at the confluence of both limbs. A single tubule is present in the ventral part of the dorsal limb. This points in posterodorsal direction and does not reach the posterior margin of the preopercle. The infraorbital canal runs close to the dorsal, or anterior margin of the infraorbital bones. The infraorbital canal is not preserved in infraorbital 1, but impressions on the bone show its position. The canal gives off at least four tubules, which apparently have reached the ventral margin of the bone. The canal continues close to the center of infraorbital 2. It gives off four tubules in infraorbital 3, which are directed posteroventrally. The first one is much shorter than the other tubules. Two tubules are present in infraorbital 4, they point posteriorly. The ventral one is long, ending close to the posterior margin of the bone; the dorsal tubule is evidently shorter. The infraorbital canal does not seem to give off any tubules in infraorbital 5.</p> <p>Vertebral column and associated bones (Pl. 1F): Seven abdominal vertebrae are exposed in the specimen, but it is assumed that few others are covered by the opercle. The autocentra are slightly longer than broad, each being slightly constricted in its middle part. Their surface is smooth, without ornamentation. The parapophyses are large, about as broad as their respective centrum. The parapopyses are fused to the autocentra lateroventrally and bear a short, very thin process at its lateroventral margin. The processes point posteroventrally. Ribs are not preserved. The neural arches are not fused to their centra. Each arch bears a thin epineural process, which is directed posteriorly. The epineural processes are united with the neural arches also by thin bony lamellae. These lamellae exceed in anterior and dorsal direction and form a small anterodorsal process. The neural spines are thin and form an angle of about 45° with the vertebral column. Supraneural bones are not preserved.</p> <p>Pectoral girdle and fin (Fig. 6; Pl. 1E): The preserved bones of the pectoral girdle are: cleithrum, supracleitrum, and two postcleithra. The cleitrum is composed of two limbs, a vertical dorsal and a horizontal ventral one. The dorsal limb seems to be longer than the ventral one. Several fine grooves and ridges, running parallel to the posterior margin of the bone are present. These seem to be growth lines. The elongate supracleithrum is hardly damaged. A long and narrow bone is present posterior to the cleithrum. This bone is identified as postcleithrum 1. A second postcleithrum is present ventrally to postcleithrum 1. This element is incompletely preserved, so that its shape remains unknown. Several lepidotrichia of the pectoral fin (probably originating from both fins) lie ventrally and posteriorly to the cleithrum, they are poorly preserved. At least some rays are segmented.</p> <p> Remark: Nybelin (1974) pointed out that <i>L. normandica</i> Nybelin, 1962 might be identical with <i>L. pachystetus</i> Sauvage, 1873. This assumption is based on the relatively low number of unbranched tubules in the preopercular sensory canal and a similar shaped opercle in both species. Due to Sauvage’s insufficient description and the loss of the holotype of <i>L</i>. <i>pachystetus</i> the identity of both species cannot be confirmed (see Nybelin 1974). The herein examined specimens of Leptolepidae sp. 1, <i>Proleptolepis</i> -like, <i>Leptolepis</i> sp. 1 and <i>L</i>. <i>jaegeri</i>, do also have a relatively low number of unbranched tubules in the preopercular sensory canal, but differ from <i>L</i>. <i>normandica</i> in other characters. This shows that the number and shape of the tubules cannot be used as sole character for the identification of the species. Furthermore, we disagree with Nybelin’s (1962, 1974) interpretation of the shape of the opercle in <i>L</i>. <i>normandica</i> (see below). For these reasons, we retain the use of the name <i>L</i>. <i>normandica</i>, following the nomenclature of Nybelin (1962, 1974).</p>Published as part of <i>Konwert, Martin & Stumpf, Sebastian, 2017, Exceptionally preserved Leptolepidae (Actinopterygii, Teleostei) from the late Early Jurassic Fossil-Lagerstätten of Grimmen and Dobbertin (Mecklenburg-Western Pomerania, Germany), pp. 249-296 in Zootaxa 4243 (2)</i> on pages 263-266, DOI: 10.11646/zootaxa.4243.2.2, <a href="http://zenodo.org/record/399081">http://zenodo.org/record/399081</a>
