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International audience; A pleuropholid fish is described for the first time from the Upper Cretaceous (Cenomanian) Akrabou Formation, Agoult locality, southeastern Morocco. The new material, consisting of a single complete specimen, is attributed to a new species, Pleuropholis danielae, and is diagnosed by its slender body shape, the absence of a leptolepid notch in the dentary, a broad maxilla, covering almost the entirely lower jaw, and flank scales with an unserrated posterior margin. This species represents the last known occurrence of Pleuropholidae, a group so far unknown from the Late Cretaceous.

The previously alleged ‘perleidid’ genus Peltoperleidus is a stem-neopterygian fish taxon with two or three horizontal rows of notably deepened flank scales. Until recently, members of this genus were known only from the Ladinian (late Middle Triassic) or near the Anisian/Ladinian boundary (~242 Ma) in southern Switzerland and northern Italy. Here, I report the discovery of a new species of the genus, Peltoperleidus asiaticus sp. nov., based on three well-preserved specimens from the Anisian (early Middle Triassic, ~244 Ma) of Luoping, eastern Yunnan, China. The discovery extends the geological range of Peltoperleidus by approximately two million years and documents the first record of the genus in Asia. Similar to its relatives (represented by P. macrodontus) from Europe, P. asiaticus sp. nov. is likely a small-sized durophagous predator with dentition combining grasping and crushing morphologies. Results of a cladistic analysis unite four species of Peltoperleidus as a monophyletic group within the Louwoichthyiformes, and suggest that the presence of two horizontal rows of notably deepened scales was independently evolved in Peltoperleidus and another stem-neopterygian taxon Altisolepis. P. asiaticus sp. nov. is nested at the base of Peltoperleidus, and a new family Peltoperleididae is proposed for the genus, contrasting the previous placement of Peltoperleidus in the poorly defined, paraphyletic ‘Perleididae’. Comparative studies of the basal peltoperleidid from China with its younger relatives from Europe provide new insights into the evolutionary origin and paleogeographic distribution of this clade.

1. Introduction A diverse and very rich paleontological material from marine Upper Cretaceous and Paleogene deposits was discovered by the Belgian explorer and paleontologist Edmond Dartevelle during the two expeditions (1933 and 1937-38) that he conducted in the Lower Congo Basin and in the Cabinda Territory. The numerous fossil fishes that he found there were described in three monographs (Dartevelle & Casier, 1943, 1949, 1959). However, some fish remains among the recorded material were left as undetermined samples and were not mentioned in the three monographs. One of these undescribed specimens was labelled by Edgar Casier as “Neopterygii indetermine”. It is a member of the teleostean order Gonorynchiformes and of the family Chanidae. The aim of our paper is to describe this sample and to determine its relationships. 2. Stratigraphy The specimen was discovered in 1937 in the Landana cliff section, a marine Paleogene fossil site located in the Cabinda enclave, a province of Angola. This fossil site, currently located on the west African coast at 2 to 3 km south of the Shiloango river mouth (GPS coordinates: 05° 13’ S, 12° 07’ E), forms part of the Paleogene marine margin of the Congo Basin (see Dartevelle & Casier, 1943, p. 48, fig. 23). The lithological sequence of the Landana section has been subdivided into 32 sedimentary layers (“couches” in Dartevelle & Casier, 1943). The bio- and chemostratigraphic context of these layers has recently been unraveled in order to ref

Neopterygii is a taxonomically diverse clade of ray-finned fishes, including Teleostei, Holostei and closely related fossil taxa. The Colobodontidae is a stem group of large-sized neopterygians with a durophagous feeding adaption from the Middle to Late Triassic marine ecosystems in Europe and South China. Here, we report the discovery of a new colobodontid, Feroxichthys panzhouensis sp. nov., based on a well-preserved specimen from the early Middle Triassic (Anisian) of Panzhou (formerly known as Panxian), Guizhou, China. The discovery extends the geographical distribution of Feroxichthys from eastern Yunnan into western Guizhou, and demonstrates a more rapid diversification of early colobodontids than previously thought. The new species possesses diagnostic features of Feroxichthys (e.g., a fused lacrimal-maxilla), but it is easily distinguished from the type species Feroxichthys yunnanensis and other colobodontids by some derived features on the skull and, especially, the relatively short and deep body with a prominent postcranial hump. This body form, previously unknown in colobodontids, implicates a morphological adaptation to structurally complex habitats in light of ecological studies of modern ray-finned fishes with a similar body form. In addition, the feeding apparatus suggests a more obligate durophagous diet for F. panzhouensis sp. nov. than other colobodontids. Results of a cladistic analysis recover the new species as a sister taxon of F. yunnanensis within the Colobodontidae, and suggest that a hump-backed body form has independently evolved multiple times in Triassic neopterygians. As such, the new finding provides an important addition for our understanding of the morphological and ecological diversity of neopterygian fishes from the Triassic marine ecosystems in South China.

Neopterygii is a large group of ray-finned fishes which underwent a rapid radiation in the Middle Triassic. Until recently, 11 stem neopterygians have been recovered from the early Middle Triassic Luoping Biota in eastern Yunnan, China, and they are small to medium-sized fishes. Here, I report the discovery of a new stem neopterygian, Feroxichthys yunnanensis gen. et sp. nov. from the Luoping Biota, which represents the first evidence of large-sized stem neopteygians in this biota with a total length of ~340 mm (290 mm in standard length). The skull of the new taxon is exceptionally well-preserved, showing some peculiar features rarely known in other stem neopterygians, for example fusion of paired premaxillae, fusion of lacrimal with maxilla, and a fused parieto-dermopterotic with a strong posterior process. Phylogenetic studies recover Feroxichthys as a basal colobodontid, and a revised diagnosis of this family is presented. The feeding apparatus indicates that Feroxichthys might have been predominantly durophagous, resembling other colobodontids. However, the anterior peg-like teeth in the jaws of Feroxichthys are much longer and stronger than other colobodontids, enabling a more powerful initial prey capture before food was passed posteriorly to molariform teeth for crushing in the oral cavity. As a mysterious large durophagous predator previously unknown from the Luoping Biota, the new finding is important not only for understanding the early diversification of neopterygians during this age but also for investigating the trophic structure in this marine ecosystem.

Four complete platysiagid fish specimens are described from the Luoping Biota, Anisian (Middle Triassic), Yunnan Province, southwest China. They are small fishes with bones and scales covered with ganoine. All characters observed, such as nasals meeting in the midline, a keystone-like dermosphenotic, absence of post-rostral bone, two infraorbitals between dermosphenotic and jugal, large antorbital, and two postcleithra, suggest that the new materials belong to a single, newPlatysiagumspecies,P. sinensissp. nov. Three genera are ascribed to Platysiagidae:Platysiagum,HelmolepisandCaelatichthys. However, most specimens of the first two genera are imprints or fragmentary. The new, well-preserved specimens from the Luoping Biota provide more detailed anatomical information than before, and thus help amend the concept of the Platysiagidae. The Family Platysiagidae was previously classed in the Perleidiformes. Phylogenetic analysis indicates that the Platysiagidae is a member of basal Neopterygii, and its origin seems to predate that of Perleidiformes. Moreover, platysiagid fishes are known from the Middle Triassic of the western Tethys region. The newly found specimens of platysiagids from Luoping provide additional evidence that both eastern and western sides of the Tethys Ocean were biogeographically more connected than previously thought.

A large fossil specimen could easily go unnoticed, especially when the specimen osteology is not well known, is usually represented by fragmentary material and has a sparsely ossified skeleton resulting in low preservation potential. This is particularly true for the suspensionfeeding Pachycormiformes, a clade of actinopterygians. This work provides the description of a complete gill raker recovered from the Upper Jurassic (lower Tithonian) levels of the Vaca Muerta Formation at Cerro Lotena, Neuquen Province, southwestern Argentina. The specimen is referred to the suspension-feeding pachycormid, Leedsichthys, based on similarities in size and shape morphology of the gill raker stalk, the shape of the gill raker base and for having similar morphology of the fimbriae (growing tongue-like distally). Although suspension-feeding pachycormids are known mainly from Laurasia, some remains were also recovered from Gondwana. The lower Tithonian Leedsichthys record extends the geographic and stratigraphic...

Lepisosteoid-type scales are described in detail for the first time from the Barremian-Aptian (Lower Cretaceous) Quirico Formation of the Sanfranciscana Basin, Southeastern Brazil. The specimens studied herein have been recovered from a new outcrop in northern Minas Gerais state and comprise a few nearly complete posterior scales and hundreds of scale fragments extracted from the sedimentary matrix. The scales are rhombic and preserve both the ganoine and the basal plate. The ganoine layer is thin, pierced by foramina and ornamented by microtubercles, showing the typical arrangement of superimposed sheets. The basal plate is composed by lamellar and woven bone, with flattened and isodiametric osteocytes, canaliculi of Williamson, and Sharpey's fibers. An EDS analysis suggests diagenetic alteration of the basal plate but not the ganoine layer. The morphology of the specimens is similar to that of early neopterygian fishes, including ginglymodians and aspidorhynchids. A less inclusive identification is hampered by the fragmentary condition of the material and the lack of specific diagnostic features in this type of scale. This can be also extended to some isolated scales commonly referred to Lepidotes recovered from several sedimentary basins in the Jurassic-Cretaceous of Brazil. The results add a new record of ganoid scales in the Sanfranciscana Basin, and highlight the importance of more complete specimens rather than isolated scales for a genus-level identification of early neopterygian fishes.

Our understanding of the ecology and phylogenetic relationships of Pachycormiformes, a group of Mesozoic stem teleosts including the iconic Leedsichthys, has often been hindered by a lack of comprehensive morphological information. Micro-CT scanning of an articulated, though flattened, cranium of the edentulous Martillichthys renwickae from the Middle Jurassic (Callovian) Oxford Clay of the UK reveals previously unknown internal details of the most complete suspension-feeding pachycormiform skull known, including the palate, braincase, and branchial skeleton. The latter preserves gill rakers with elongate, pointed projections similar to those of Asthenocormus, in contrast to the finer fimbriations associated with Leedsichthys. We also reinterpret some previously described features, including dermal bone patterns of the snout, skull roof, and lower jaw, and the morphology of the ventral hyoid arch. These new anatomical data reinforce the phylogenetic placement of Martillichthys as part of the Jurassic clade of edentulous pachycormiforms. The elongated skull geometry of these Jurassic taxa is strikingly similar to that of Ohmdenia, the sister taxon to edentulous pachycormiforms, but contrasts sharply with the morphology of the Late Cretaceous edentulous pachycormiform Bonnerichthys, raising questions over the phylogenetic relationships among these taxa. Most significantly, Martillichthys shows specialized characters with a restricted phylogenetic distribution among suspension-feeding pachycormiforms, including the distinctive gill rakers and a greatly extended occipital stalk. Our analysis of Martillichthys supports past interpretations of a close relationship with Asthenocormus, and provides a model for interpreting the less complete remains of other members of this enigmatic group of fishes.

Here we describe new pycnodontiform fish material recovered from the marine Agrio Formation (lower Valanginian–lower Hauterivian) of the NeuquØn Province in the south-western of Patagonia, Argentina. The new material include an incomplete skull and an incomplete prearticular dentition. The incomplete skull consists of some dermal and endochondral elements as well as dental remains and represents a new large-sized gyrodontid that is referred to a new species, Gyrodus huiliches. Gyrodus huiliches sp. nov. is characterized by a unique combination of tooth crown ornamentations and tooth shape separating it easily from all known Gyrodus species. The incomplete prearticular dentition shows a tooth arrangement and sculpture that resembles that of “Macromesodon” agrioensis –the previously only known pycnodontiform in the area. This allows revising this species, which was based on an isolated vomerine dentition and which we refer to a new genus, Tranawuen. The new Patagonian fishes reported here expand the knowledge of South American pycnodontiforms. We hypothesize that meanwhile the new Patagonian genus – Tranawuen– diverged from Gyrodus after it migrated into the eastern Pacific through the Hispanic Corridor during the Late Jurassic, the new species –Gyrodus huiliches– most likely diverged from a Central or South American species of Gyrodus. Both represent the youngest gyrodontid records and simultaneously the southernmost Early Cretaceous occurrences of pycnodontiform fishes., Facultad de Ciencias Naturales y Museo

A series of well-preserved fossil assemblages from the Middle Triassic marine rock succession in Southwest China provide unique evidences for studying the early evolution of holostean fishes, including Halecomorphi (e.g., bownfin) and Ginglymodi (e.g., gars). Ginglymodi have the earliest record in the early Middle Triassic (Anisian, ∼244 Ma) of China, represented byKyphosichthysandSangiorgioichthys suifrom Yunnan andS. yangjuanensisfrom Guizhou. Here, we report the discovery of a new ginglymodian,Fuyuanichthys wangigen. et sp. nov., based on 22 well-preserved specimens from the lower part of the Zhuganpo member of the Falang Formation in eastern Yunnan and western Guizhou, which documents the first discovery of convincing ginglymodians from the late Middle Triassic (Ladinian, ∼240 Ma) Xingyi biota in China.Fuyuanichthyspossesses a unique combination of features that easily distinguishes it from other ginglymodians, such as presence of a median gular and short and edentulous maxillae, and absence of a supramaxilla and supraorbitals. As one of the smallest known ginglymodians with a maximum standard length of ∼75 mm, the new finding further supports that the Middle Triassic Ginglymodi have a relatively small range of body sizes compared with the Halecomorphi from the same ecosystems in China. Results of a phylogenetic analysis recoverFuyuanichthysas a sister taxon toKyphosichthysat the ginglymodian stem, and provide new insights into the early evolution of this clade.

Dapediumis one of the most abundant and diverse genera of ganoid fishes from the Early Jurassic fossil lagerstätte of Europe. In spite of its abundance, however, its timing of extinction is poorly constrained, with the youngest described material being Early Jurassic in age. We describe new diagnostic and relatively complete material of a large species ofDapedium(standard length estimated at 50 cm) from the Middle Jurassic (earliest Aalenian) Opalinuston Formation of Baden-Württemberg, Germany. The Aalenian material represents a distinct species,D. balleisp. nov., differing from Early Jurassic species in a unique combination of characters pertaining to the shape of the dermal skull elements, pectoral fin position, and scale shape and ornamentation. However, althoughD. balleisp. nov. exhibits a unique combination of characters, there are no autapomorphies with which to distinguish it from the Toarcian species ofDapedium.Dapedium balleirepresents the geologically youngest species ofDapedium, extending the range of this genus into the Middle Jurassic. The Opalinuston Formation fills an important gap in the marine vertebrate fossil record, and finds from this horizon have the potential to greatly improve our understanding of evolutionary dynamics over this period of faunal transition.

The functional morphology of the jaw apparatus and the skull and the feeding habits of the extinct pycnodont fishes are reconstructed in comparison with some extant halecostomes. For this a short review of the functional units of the pycnodont head is given. The feeding mechanisms of pycnodonts exhibit a transition from simple stereotypic feeding kinematics, which are characteristic for primitive actinoptergians, to the modulating feeding kinematics of advanced teleosts and is called limited modulating feeding kinematics herein. Two structural specialisations which are found in halecostomes (operculum with distinct m. levator operculare and the interopercular bone with the interopercular ligament) are supposed to be absent in pycnodonts, whereas they maintain the two primitive couplings for direct mandibular depression (epaxial muscles – neurocranium, hypaxial muscles -cleithrum-m. sternohyoideus – hyoid apparatus). Advanced pycnodonts developed a new structure (upper jaw protrusion, resulting in an enlargment of the buccopharyngeal cavity), that is absent in halecomorphs (e.g., Amia calva) and basal pycnodonts (e.g., Anduafrons, Mesturus). The premaxillae and maxillae are firmly fixed in basal pycnodonts, whereas the premaxillae and maxillae are free and movable in advanced pycnodonts. Pycnodonts were benthic foragers with a combination of biting or nipping and suction feeding based on the "truncated cone morphology" of the buccopharyngeal cavity. It is concluded, that pycnodonts certainly were omnivorous feeders with a general broad range of prey. But they were also a highly specialised group on generic level in respect to their prey. This is indicated by gut contents, as far as they are known, which comprise only monospecific remains of shelled invertebrates (e.g., spines of echinoderms, shells of bivalves). The ecological demands of pycnodonts are discussed. Die funktionelle Anatomie des Nahrungsaufnahmeapparates sowie das Fressverhalten der seit dem Eozän ausgestorbenen Neopterygier-Gruppe der Pycnodontier wird im Vergleich zu einigen rezenten Halecostomen (Amia calva, verschiedene Teleosteer) untersucht und diskutiert. Dazu wird eine kurze Übersicht über die funktionellen Einheiten des Pycnodontierschädels gegeben. Die Kinematik des Nahrungsaufnahmeapparates der Pycnodontier stellt einen Übergang von der einfachen, stereotypischen Kinematik primitiver Actinopterygier zu der modulierenden Kinematik fortschrittlicher Teleosteer dar und wird hier als limitierte, modulierende Kinematik bezeichnet. Zwei structurelle Spezialisationen, die bei Halecostomi entwickelt sind (Operculum mit distinkten m. levator operculare und das Interoperculare mit dem interoperculare Ligament) fehlen bei Pycnodontiern, wogegen sie die zwei primitiven Verbindungen zwischen den epaxialen Muskeln und dem Neurocrani-um und zwischen den hypaxialen Muskeln, dem Cleithrum und dem Sternohyoidmuskel für die direkte Unterkieferabsenkung beibehalten. Fortschrittliche Pycnodontier entwickeln aber eine neue Struktur (bewegliches Maxillare und Premaxillare zur Erweiterung des buccopharyngealen Raumes), die bei Halecomorphen als auch ursprünglichen Pycnodontiern (z. B. †Ardua-frons, †Mesturus) fehlt: Maxillare und Prämaxillare werden aus dem Schädelverband gelöst und beide werden gegeneinander beweglich Während der Mandibulardepression schwingt das nun freie Maxillare um einen vorderen Artikulationszapfen antero-ventrad und drückt das Prämaxillare nach vorne in Richtung Beute. Die ökomorphologische Untersuchung zeigt, dass der Rachenraum als „truncated-cone”, wie er für Teleosteer mit ausgeprägtem Schnappsaugmechanismus typisch ist, rekonstruiert werden kann. Die Kinematik des Kieferapparates der Pycnodontier repräsentiert somit eine Kombination aus reinem Beißen und Schnappsaugen. Pycnodontier ernährten sich vermutlich omnivor sowohl von schalentragenden als auch schalenlosen Invertebraten ernährten. Vermutlich waren die einzelnen Gattungen aber hochspezialisierte Beutegreifer. Dies lässt sich mithilfe der überlieferten Mageninhalte zeigen, die monospezifisch für jede Gattung sind. doi:10.1002/mmng.20010040110

Dapedium pholidotum (Agassiz, 1832) (Actinopterygii, Neopterygii) is redescribed based on new material from the Posidonia Shale (Early Jurassic: Early Toarcian) of Germany. Dapediiformes ord. nov. is introduced for Dapedium Leach, 1822 and other deep-bodied Mesozoic neopterygians. The species diagnosis of D. pholidotum is amended. Comparison with D. stollorum Thies & Hauff, 2011 and D. caelatum Quenstedt, 1858, also from the Lower Jurassic Posidonia Shale, shows that D. pholidotum is unique in having: (1) a length/height ratio of the operculum of c. 0.73, whereas in D. stollorum and D. caelatum this value reaches only c. 0.58; (2) a length/width ratio of the gular plate of c. 1.6, whereas in D. stollorum and D. caelatum this value is 1.3; (3) 27 or more caudal fin lepidotrichia, whereas in D. stollorum and D. caelatum there are 24 and 25 lepidotrichia, respectively; (4) at least 26 dorsal fin lepidotrichia, whereas D. stollorum and D. caelatum possess only 24 dorsal fin lepidotrichia each; and (5) a lengt...

Aspidorhynchiformes as a whole are incompletely understood. Here, a new aspidorhynchiform, Jonoichthys challwa gen. et sp. nov., is described based on a single three-dimensionally preserved specimen recovered from Upper Jurassic marine rocks of the Vaca Muerta Formation, Neuquén, southern Argentina. The new taxon is based on a unique combination of characters (e.g., large skull roof plate composed by the fusion of certain bones; 'L'-shaped preoperculum with a single main preopercular sensory canal that lacks sensory tubules; three predentary tooth rows; an accessory cusp in the teeth of the median predentary tooth row, and a robust and deep body). It is expected that the morphological information provided here could be useful to further understanding of aspidorhynchiform phylogeny and Neuquén Basin biodiversity. Fil: Gouiric Cavalli, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina

Ray-finned fishes (Actinopterygii) constitute approximately half of all living vertebrate species. A stable hypothesis of relationships among major modern lineages has emerged over the past decade, supported by both anatomy and molecules. Diversity is unevenly partitioned across the actinopterygian tree, with most species concentrated within a handful of geologically young (i.e. Cretaceous) teleost clades. Extant non-teleost groups are portrayed as ‘living fossils’, but this moniker should not be taken as evidence of especially primitive structure: each of these lineages is characterized by profound specializations. Attribution of fossils to the crowns and apical stems of Cladistia, Chondrostei and Neopterygii is uncontroversial, but placements of Palaeozoic taxa along deeper branches of actinopterygian phylogeny are less secure. Despite these limitations, some major outlines of actinopterygian diversification seem reasonably clear from the fossil record: low richness and disparity in the Devonian; elevated morphological variety, linked to increases in taxonomic dominance, in the early Carboniferous; and further gains in taxonomic dominance in the Early Triassic associated with earliest appearance of trophically diverse crown neopterygians.

Reconstructing the feeding ecology of fossil fishes can be difficult, but new mechanical approaches enable reasonably reliable inferences by comparison with living forms. Here, the feeding ecology of one of the most iconic and abundant actinopterygians of the Early Jurassic, Dapedium, is explored through detailed anatomical study and functional analyses of jaw mechanics. Mathematical models derived from modern teleost functional morphology are applied, to ascertain the transmission of force through the jaws of Dapedium. A number of features not previously identified in the genus are described, and the dentition is described in full for the first time. The analysis of the functional morphology of Dapedium, in combination with its jaw anatomy and dentition, indicates that the genus was well adapted to a durophagous feeding habit, although indirect evidence suggests a more generalist feeding mode. Being a generalist durophage may explain the success of the genus in the aftermath of the end-Triassic extinction event and its radiation in the Early Jurassic, as indicated by the ubiquity of Dapedium fossils throughout the Lower Lias.

The Permian and Triassic were key time intervals in the history of life on Earth. Both periods are marked by a series of biotic crises including the most catastrophic of such events, the end-Permian mass extinction, which eventually led to a major turnover from typical Palaeozoic faunas and floras to those that are emblematic for the Mesozoic and Cenozoic. Here we review patterns in Permian-Triassic bony fishes, a group whose evolutionary dynamics are understudied. Based on data from primary literature, we analyse changes in their taxonomic diversity and body size (as a proxy for trophic position) and explore their response to Permian-Triassic events. Diversity and body size are investigated separately for different groups of Osteichthyes (Dipnoi, Actinistia, 'Palaeopterygii', 'Subholostei', Holostei, Teleosteomorpha), within the marine and freshwater realms and on a global scale (total diversity) as well as across palaeolatitudinal belts. Diversity is also measured for different palaeogeographical provinces. Our results suggest a general trend from low osteichthyan diversity in the Permian to higher levels in the Triassic. Diversity dynamics in the Permian are marked by a decline in freshwater taxa during the Cisuralian. An extinction event during the end-Guadalupian crisis is not evident from our data, but 'palaeopterygians' experienced a significant body size increase across the Guadalupian-Lopingian boundary and these fishes upheld their position as large, top predators from the Late Permian to the Late Triassic. Elevated turnover rates are documented at the Permian-Triassic boundary, and two distinct diversification events are noted in the wake of this biotic crisis, a first one during the Early Triassic (dipnoans, actinistians, 'palaeopterygians', 'subholosteans') and a second one during the Middle Triassic ('subholosteans', neopterygians). The origination of new, small taxa predominantly among these groups during the Middle Triassic event caused a significant reduction in osteichthyan body size. Neopterygii, the clade that encompasses the vast majority of extant fishes, underwent another diversification phase in the Late Triassic. The Triassic radiation of Osteichthyes, predominantly of Actinopterygii, which only occurred after severe extinctions among Chondrichthyes during the Middle-Late Permian, resulted in a profound change within global fish communities, from chondrichthyan-rich faunas of the Permo-Carboniferous to typical Mesozoic and Cenozoic associations dominated by actinopterygians. This turnover was not sudden but followed a stepwise pattern, with leaps during extinction events.

The scanilepiform ray-finned fish Fukangichthys longidorsalis, from the Middle Triassic non-marine Kelamayi Formation of Xinjiang, China, was previously described incompletely, with many of its morphological characteristics unnoticed or misidentified. This study provides a revision of this problematic taxon based on an extensive reexamination of the original fossil material. Newly recognized anatomical information includes a plate-like quadratojugal, a triangular dermohyal, a wedge-shaped angular, two infraorbitals, three supraorbitals, fringing fulcra on the pectoral fins, and conical, acrodin-capped teeth in the jaws. Results of a phylogenetic analysis confirmed Fukangichthys as a scanilepiform within the Neopterygii, and provided new insights into the evolution of early actinopteran fishes. Cosmoptychius, previously regarded as the oldest stemgroup neopterygian, and Brachydegma, previously hypothesized to be the oldest halecomorph, are here reinterpreted as a stem-group actinopteran and a stem...

Two species of the neopterygian genus †Lophionotus Gibson, 2013, are described. Specimens of †Lophionotus chinleana, new species, were previously and recently collected from freshwater deposits in the Upper Triassic Chinle Formation of Lisbon Valley, southeastern Utah. †Semionotus kanabensis Schaeffer and Dunkle, 1950, from lacustrine deposits in the Lower Jurassic Moenave Formation of southwestern Utah, is herein redescribed and attributed to the genus †Lophionotus, based on shared characters, including the infraorbital in the posteroventral corner of the orbit being expanded and contacting the anterior ramus of the preoperculum. Both new species of †Lophionotus are distinct from †L. sanjuanensis Gibson, 2013, in that they lack a postcranial hump, deep body, dense tuberculation, and ventrally expanded preoperculum. The addition of two new species lends to a revised generic description of the genus †Lophionotus. A phylogenetic analysis infers a monophyletic †Lophionotus sister to the genus †Semionotus, an...

The Triassic was a time of turmoil, as life recovered from the most devastating of all mass extinctions, the Permo-Triassic event 252 million years ago. The Triassic marine rock succession of southwest China provides unique documentation of the recovery of marine life through a series of well dated, exceptionally preserved fossil assemblages in the Daye, Guanling, Zhuganpo, and Xiaowa formations. New work shows the richness of the faunas of fishes and reptiles, and that recovery of vertebrate faunas was delayed by harsh environmental conditions and then occurred rapidly in the Anisian. The key faunas of fishes and reptiles come from a limited area in eastern Yunnan and western Guizhou provinces, and these may be dated relative to shared stratigraphic units, and their palaeoenvironments reconstructed. The Luoping and Panxian biotas, both from the Guanling Formation, are dated as Anisian (Pelsonian) on the basis of conodonts and radiometric dates, the former being slightly older than the latter. The Xingyi biota is from the Zhuganpo Formation, and is Ladinian or early Carnian, while the Guanling biota is from the overlying Xiaowa Formation, dated as Carnian. The first three biotas include extensive benthos and burrowing in the sediments, and they were located in restricted basins close to shore. Further, even though the Luoping and Panxian biotas are of similar age, their faunas differ significantly, reflecting perhaps palaeogeographically isolated basins. Between the time of the Xingyi and Guanling biotas, there was a major transgression, and the Guanling biota is entirely different in character from the other three, being dominated by pelagic forms such as large floating crinoids attached to logs, very large ichthyosaurs and thalattosaurs, and pseudoplanktonic bivalves, with no benthos and no burrowing. Phylogenetic study of the fishes and marine reptiles shows apparently explosive diversification among 20 actinopterygian lineages very early in the Early Triassic, but a later expansion of marine reptile groups, in the late Olenekian and early Anisian. This offset in diversification patterns is matched by comparisons of feeding guild categories and body size data. New research tools will shed considerable light on the phylogenetic and ecological implications of recovery of mairne vertebrates in the Triassic.

A new species of hump-backed semionotiform fish, Lophionotus sanjuanensis, gen et sp. nov., is described based on specimens recently and previously collected from the Upper Triassic Church Rock Mem...

The fishes of the genus Aspidorhynchus (Aspidorhynchidae) are among the most abundant predators in the palaeolagoons of the Solnhofen archipelago (Late Jurassic, southern Germany). They have been known since the end to the nineteenth century and the last revision of the genus was published more than 20 years ago. During these last two decades, numerous complete and excellently preserved specimens have been collected. The high morphological diversity shown by the new material made a new revision of these fishes necessary. This new taxonomic revision led us to revalidate the species A. ornatissimus Agassiz, 1834, which has hitherto been considered a junior synonym of the type species of the genus, A. acutirostris (Blainville, 1818), as well as to recognize high intraspecific variation in the latter species. These results helped to improve the distinction and, thus, the diagnoses of A. acutirostris, A. ornatissimus, and A. sanzenbacheri Brito and Ebert, 2009, which are the three valid species of this genus in the Solnhofen archipelago. We have been able to explain most of the intraspecific diversity of A. acutirostris by means of patterns of ontogenetic variation that encompass most of the other nominal species, thus largely reflecting early taxonomic hypotheses. Furthermore, the detailed morphological study led us to the recognition of some important anatomical structures previously unknown for aspidorhynchids: a connection between the temporal, infraorbital and supraorbital sensory canals in the frontal bone, the presence of an Y-shaped antorbital bone, and the presence of an interoperculum.

We report on a new semionotiform taxon, Scheenstia zappi gen. et sp. nov., from Schamhaupten in the Late Jurassic limestones of the Franconian and Swabian Alb, southern Germany. Although the taxon is so far represented by a single specimen, excellent preservation allows a detailed description of its skeletal anatomy. Scheenstia zappi is distinguished by the presence of a sensory canal in the supraorbital bones and a saddle-like articular surface in the quadratojugal, both features so far unknown in other semionotiforms. The new taxon is further diagnosed by a unique combination of characters: More than three pairs of extrascapular bones; frontals less than three times longer than their maximal width; semitritorial dentition; four anterior infraorbitals; middle pit line contained in a groove in the dermopterotic and parietal; concave posterior border of the angular, robust bugle-like process of the posttemporal bone; large basal fulcra; eleven fin rays in the lower lobe of the caudal fin (below the lateral line); and a first, scale-like caudal fin ray reduced. Among semionotiforms it most closely resembles Lepidotes, in particular the large tritorial forms of the Late Jurassic and Early Cretaceous of Europe, such as L. mantelli, L. maximus and L. laevis. The peculiar shape of the quadratojugal in Scheenstia zappi resembles the condition in some basal teleosts in which a ventral articular surface of the quadrate probably served in the rotation of the lower jaw. Copyright © 2011 The Natural History Museum. Fil: López-Arbarello, Adriana. Bayerische Staatssammlung fur Palaontologie und Geologie; Alemania Fil: Sferco, Marta Emilia. Bayerische Staatssammlung fur Palaontologie und Geologie; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina

A new scanilepiform, Beishanichthys brevicaudalis gen. et sp. nov., is named and described based on fossils from the Lower Triassic lake deposits exposed in Beishan area, Gansu Province, China. The discovery documents a new record of this group, which is significantly older than other known scanilepiforms from China, and is slightly younger than Evenkia from the Lowest Triassic of Central Siberia. Although the Beishan beds were previously interpreted as Late Permian in age, based on megaplant fossils, this new discovery supports the reinterpretation of the deposits as Early Triassic in age, based on vertebrate fossils from the same locality and horizon. Phylogenetic analysis was conducted to resolve the relationships of Scanilepiformes with other actinopterygian clades, and the inter-relationships within Scanilepiformes. Contrary to previous thought that scanilepiforms are closely related to the Amiidae, the phylogenetic results of this study recognize the Scanilepiformes as stem-group neopterygians. Relationships of the Scanilepiformes and Australosomus with other neopterygians remain unresolved. With a characteristic long-based dorsal fin, scanilepiforms represent a small group that emerged in Early Triassic freshwater environments, inhabited Eurasia and North America during the Middle–Late Triassic, briefly invaded the marine environment by the Late Triassic in Europe, and became extinct at the end of Triassic. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161, 595–612.

Microstructural scanning electron microscope investigation was performed on sectioned and surface-etched isolated, prehensile teeth of the Late Triassic semionotiform species Sargodon tomicus and Pycnodontidae incertae sedis from the Late Cretaceous. The teeth of both taxa display a system of vascular canals penetrating the dentine and the overlying hypermineralized acrodin cap; small tubules are radiating at an angle to the long axis of the canals, interpreted as residual spaces left by odontoblast cell processes. This is the first detailed account of vascular acrodin encountered in a pycnodont species. New information is revealed also about Sargodon dental histology in the shape of mineralized remnants of the basal lamina at the acrodin–dentine junction. This implies that deposition of the acrodin organic matrix proceeded centrifugally by the cells of the inner dental epithelium, probably with minor collagen contribution from odontoblasts. This is contrary to the more typical centripetal formation (beneath the basal lamina) of the acrodin layer implied for the studied pycnodontid teeth. The rare occurrences of vascular acrodin within Actinopterygii, and the demonstrated differences in its histogenesis, do not suggest the usefulness of the tissue as systematic character but rather point to its adaptive significance. The superficial increase in the order of acrodin bundle orientation, observed in both species, is similarly regarded as convergently acquired mechanical adaptation. The observed uneven shape of crystallite rows and lesser degree of mineralization of the inner collariform ganoin, compared to its outer portion, is indicative of epithelial-ectomesenchymal interaction and qualifies the tissue as enameloid. Microsc. Res. Tech., 2011. © 2010 Wiley-Liss, Inc.

Citation for this article: Ebert, M., and J. A. Lane. 2018. Rediscovery of the missing type specimen of ‘Ophiopsis’ aequalis (Neopterygii: Halecomorphi), a small paleontological mystery solved. Jou...

The continental deposits of the Cuyana Basin, western Argentina, have yielded the most diverse, but so far almost unstudied, Triassic ichthyofaunas of South America. Here, we review these faunas and show that only eight of the 29 named taxa can be considered valid, includ- ing the chondrostean Neochallaia, the acrolepid Challaia, Guaymayenia, a taxon of uncertain affinities, and five species of the perleidiform family Pseudobeaconiidae. The first three taxa most probably come from Middle Triassic sediments, while the pseudobeaconiids are of Late Triassic age. Other material, although not diagnostic, probably rep- resents other species, and thus, the diversity of actinoptery- gians in the Cuyana basin is certainly higher than currently recognized. For the Late Triassic fish fauna, the absence of crown-group neopterygians and a single record of a sarcop- terygian is noteworthy and probably indicates some degree of endemism in this fauna, also supported by the high abundance of pseudobeaconiids, which are unknown from other areas. Furthermore, on the basis of the age indicated by the fishes and the available geological information, we discuss the age of the local fauna of the Cerro Bayo, close to the city of Mendoza, and the Agua de la Zorra Forma- tion, Uspallata. The oldest articulated actinopterygian remains are known from the Middle Devonian, but actinopterygians are still rare during that time (Friedman and Blom 2006). They evolved rapidly during the Carboniferous and Perm- ian, and several actinopterygian lineages went to extinc- tion at the Permo ⁄ Triassic boundary. However, the actinopterygian faunas recovered very rapidly during the Triassic, especially diversifying in shallow marine and brackish environments, giving rise to the very rich and diverse actinopterygian faunas of the Middle and Late Triassic. The Triassic is, therefore, a very important per- iod in actinopterygian evolution (Benton 2004). Several major evolutionary events happened during the Triassic actinopterygian radiation. A very important event in the evolution and history of these fishes is the origin of the Neopterygii, which is marked by the acquisition of a better control of the movements of both dorsal and anal fins, and consequently the improvement in their swim- ming capabilities. Although the Neopterygii appear in the fossil record already in the Permian, their first and rapid radiation occurred during the Triassic, producing a new variety of fishes with very distinct feeding specializations

A recent collection of actinopterygian fossil fishes from a previously unreported locality in the Cenomanian or Turonian of southeastern Morocco includes a single specimen of a macrosemiid fish. Macrosemiids are more common in Jurassic and Early Cretaceous deposits, with the previously known range of the family being Late Triassic through Aptian or Albian. This discovery therefore extends the temporal range of the family into the Late Cretaceous. Moreover, macrosemiids had not previously been reported from northern Africa or the Moroccan area of the Tethys basin; therefore, this fossil also increases the geographical range of the family. The Moroccan macrosemiid is described in a new genus and species, Agoultichthys chattertoni. A phylogenetic analysis places it basal to all other genera of the family with the exception of Notagogus. Diagnostic characters of the new species include the high number of scales laterally along the body and the greater number of dorsal fin rays than in other members of the family.

Semionotus bergeri Agassiz, 1833, from the Upper Triassic (Carnian) of southern Germany, the type species ofSemionotus, is here described in detail for the first time, including so far unstudied material in the Naturkunde-Museum Coburg, which allows a fairly complete reconstruction of this fish. The species is diagnosed by the presence of long frontals, about 4 times longer than wide, with antorbital lateral processes, 6–7 posterior infraorbitals, infraorbital at the posteroventral corner of the orbit notably larger than adjacent ones, infraorbitals at the posterior border of the orbit being as deep as long, and the middle element anteroventrally expanded, dorsal fin base about two times the anal fin base.S. elegans from the Late Triassic-Early Jurassic of the Newark Supergroup in North America, is so far the best know species ofSemionotus and is the only species of this genus that has been included in phylogentic analyses. However, the comparison ofS. bergeri with other proposed speciesof Semionotus, such asS. elegans, and other semionotids casts doubt on the monophyly of this genus as currently understood, since these species exhibit a mosaic distribution of characters.

A revision of the semionotids from the Lower Cretaceous Lagarcito Formation of Argentina leads to the conclusion that only one taxon, Neosemionotus puntanus Bocchino, 1973, is represented, instead of two monospecific genera and one species of Lepidotes as originally thought. Neosemionotus shares with Lepidotes the presence of more than one suborbital arranged in one row and a long posteroventral process of the dentary, features that have previously been thought to be diagnostic of Lepidotes. On the other hand, it shares with Semionotus the presence of conspicuous dorsal ridge scales. However, Neosemionotus is unique in the characteristics of its dorsal and anal fins, which are both flanked only by high and strong paired basal fulcra. These fulcra become gradually higher/deeper posteriorly, reaching approximately the height/depth of the first fin ray. Other probable synapomorphies of Neosemionotus are the presence of a long parietal pit line, a small, approximately triangular interoperculum, the c...

Gliding adaptations in thoracopterid flying fishes represent a remarkable case of convergent evolution of overwater gliding strategy with modern exocoetid flying fishes, but the evolutionary origin of this strategy was poorly known in the thoracopterids because of lack of transitional forms. Until recently, all thoracopterids, from the Late Triassic of Austria and Italy and the Middle Triassic of South China, were highly specialized ‘four-winged’ gliders in having wing-like paired fins and an asymmetrical caudal fin with the lower caudal lobe notably larger than the upper lobe. Here, we show that the new genus Wushaichthys and the previously alleged ‘peltopleurid’ Peripeltopleurus , from the Middle Triassic (Ladinian, 235–242 Ma) of South China and near the Ladinian/Anisian boundary of southern Switzerland and northern Italy, respectively, represent the most primitive and oldest known thoracopterids. Wushaichthys , the most basal thoracopterid, shows certain derived features of this group in the skull. Peripeltopleurus shows a condition intermediate between Wushaichthys and Thoracopterus in having a slightly asymmetrical caudal fin but still lacking wing-like paired fins. Phylogenetic studies suggest that the evolution of overwater gliding of thoracopterids was gradual in nature; a four-stage adaption following the ‘cranial specialization–asymmetrical caudal fin–enlarged paired fins–scale reduction’ sequence has been recognized in thoracopterid evolution. Moreover, Wushaichthys and Peripeltopleurus bear hooklets on the anal fin of supposed males, resembling those of modern viviparious teleosts. Early thoracopterids probably had evolved a live-bearing reproductive strategy.

Jurassic fishes from the Southern Hemisphere are poorly known in comparison with those of the Northern Hemisphere. The Tithonian (Late Jurassic) deposits of Argentina have yielded a rich and taxonomically diverse ichthyofauna. However, these fishes have been only partially described and need to be revised or studied. In this paper, the putative ichthyodectiform actinopterygian Notodectes argentinus is redescribed. The holotype comes from the Vaca Muerta Formation, in the southwestern part of Mendoza Province, Argentina. It consists of an incomplete, partially articulated skull in which some of the bones are preserved in three dimensions. The specimen has a unique character combination that allows us not only to diagnose the genus Notodectes but also confirm that it is a member of the actinopterygian order Pachycormiformes. At present, Notodectes represents the first endemic pachycormiform from the Southern Hemisphere and the first specimen found in Mendoza Province (northwestern region of the Neuqu en Basin). Also, Notodectes is the first fastswimming and clearly ichthyophagous pachycormid reported from the Jurassic of South America. Fil: Gouiric Cavalli, Soledad. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cione, Alberto Luis. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

A new semionotiform fish, Isanichthys palustris gen. et sp. nov., is described from the Late Jurassic – Early Cretaceous Phu Kradung Formation, north-east Thailand. I. palustris is known from a single, nearly complete specimen found alongside abundant Lepidotes specimens at the Phu Nam Jun locality. I. palustris shows a mixture of semionotid-like characters, such as the pattern of cheek ossifications, and lepisosteid-like characters, such as the body shape and a dorsal fin opposed by an anal fin. I. palustris possesses only some of the characters currently used to define the Semionotidae. Cladistic analyses including various semionotid and gar taxa, together with Amia calva and Leptolepis coryphaenoides, suggest that the Semionotiformes (Lepisosteidae and ‘Semionotidae’) form a monophyletic clade, but the ‘Semionotidae’ taxa form an unresolved polytomy. The relationships between Semionotiformes, Halecomorphi and Teleostei are unresolved. When restricted to the best-known taxa, however, the analysis shows the monophyly of the Semionotidae sensu stricto (Semionotus + Lepidotes) and a sister-group relationship between halecomorphs and teleosts. These last two results are regarded as the preferred hypothesis for further studies. I. palustris is the only known example of a predaceous, probably piscivorous, ‘semionotid’. It illustrates the great diversity and ecological adaptation of the semionotiforms during the Late Jurassic – Early Cretaceous. We question the phylogenetic relationships of ‘ancient fishes’ founded on molecular-based trees because we suspect that the use of very few Recent taxa as representatives of previously diverse lineages is an inevitable, but important, bias in the construction of such trees.

The semionotid Lepidotes piauhyensis Roxo and Lofgren, 1936, is redescribed on the basis of original and new material obtained from the Pastos Bons Formation, ?Upper Jurassic–Lower Cretaceous of the Parnaiba Basin, in northeastern Brazil. The species is a hump-backed semionotid reaching about 480 mm standard length. It exhibits, among other characters: dermal bones of the skull roof and circumorbital series densely ornamented with tubercles, suborbitals disposed in a single row, moderately developed crushing dentition, a bony lamina on the ventral portion of the anterior ceratohyal, a complete dorsal scale row, and smooth ganoid scales of lepisosteoid type. The analysis of well preserved specimens allows the description of anatomical structures previously unknown for the species, particularly of the hyoid arch and suspensorium. Some of these structures are comparable to those of the Jurassic species Lepidotes gloriae Thies, 1989 (Cuba), Lepidotes elvensis (Blainville, 1818) (Europe), and Lepidote...

The first record of the bowfin order Amiiformes in the Late Jurassic of Portugal is reported. The single specimen comes from the Guimarota coal mine near Leiria in the Lusitanian basin. Here, Kimmeridgian strata that yielded abundant teeth, spines, and scales of selachians and actinopterygians are exposed below ground. The specimen described herein is the only disarticulated fish remain from this locality. It consists of jaw elements, parts of the palatoquadrate and opercular apparatus, an element of the postorbital series and some additional postcranial parts. The systematic position of the new specimen is discussed. The combination of characters allows assignment to the Amioidea rather than to other amiiform groups. Therefore, the specimen constitutes the first undoubted record of an amioid in the Late Jurassic of the Iberian Peninsula and contributes to the knowledge of Late Jurassic amiiform distribution patterns.

Isolated dental remains of pycnodont fishes are recorded from the upper Norian (Upper Triassic) of the Germanic basin for the first time. The only complete prearticular dentition differs significantly from those of other Late Triassic pycnodonts such as Brembodus and Eomesodon. However, because the prearticular dentition of Gibbodon, another Late Triassic pycnodont, is not known the new specimens are not attributed to any genus or species. Nevertheless, these are the first indubitable records of pycnodont fishes in the uppermost Triassic outside the Tethyan realm and consequently contribute to our knowledge about the diversity and distribution of Late Triassic pycnodonts.

A new genus and species belonging to the Macrosemiidae is described. This is the first record of a macrosemiid in the New World. The material was collected from the Early Cretaceous (Albian) Tlayua Quarries, in Tepexi de Rodriguez, central Mexico. The new taxon is a small, elongated fish that bears a combination of apomorphic and plesiomorphic characters including a divided dorsal fin with an area devoid of scales on either side, prearticular and coronoid bones with small pointed teeth, and strongly ornamented body scales. Phylogenetic analysis using PAUP revealed a close relationship of this new genus to Macrosemius and Legnonotus. The occurrence of macrosemiids in the Tlayua beds indicates a wider distribution of the group within the Tethys Ocean, and represents the westernmost record of this group of neopterygians.

A new semionotid fish, Lepidotes buddhabutrensis n. sp., is described from the continental Late Jurassic–Early Cretaceous Phu Kradung Formation, Phu Nam Jun, Kalasin Province. L. buddhabutrensis is characterized notably by the pattern of its cheek bones, by its short preorbital region, and by its numerous and well-developed premaxillary teeth. L. buddhabutrensis is provisionally placed in the genus Lepidotes; it shares, however, derived characters with other semionotids, such as Araripelepidotes and Pliodetes. To cite this article: L. Cavin et al., C. R. Palevol 2 (2003).

The dental morphology of the pycnodontid fish †Stemmatodus rhombus (Agassiz, 1844) from the Lower Cretaceous (lower Barremian) of southern Italy is described in detail. SEM pictures of vomerine and prearticular teeth are provided for the first time allowing the comparison with other Early Cretaceous pycnodonts, which are only known from isolated dental remains. The dentition of †Stemmatodus rhombus consists of incisiform grasping teeth on the paired premaxillae and dentaries and crushing teeth on the unpaired vomer and paired prearticulars. The vomerine teeth are arranged in five longitudinal rows, which display symmetry with a distinct median principal and two lateral rows. The prearticular bears three longitudinal rows. Teeth of the main row are much wider than those of the lateral ones. The tooth crowns are rather flat and expose a shallow apical depression, which is surrounded by a ring of widely-spaced small tubercles. The ornamentation and arrangement of teeth distinguishes dentitions of †Stemmatodus from all other pycnodonts. The wear pattern of the teeth is evaluated and the significance of the dental morphology in pycnodont taxonomy is discussed. In addition, the systematic position of †Stemmatodus is discussed.

A new species of Lepidotes is described on the basis of two nearly complete specimens from the ?Albian Romualdo Member of the Santana Formation, in the Araripe Basin, northeast Brazil. The new species differs from the other species of Lepidotes previously recorded in western Gondwanaland by the apomorphic presence of an axe-shaped hyomandibula, and by a unique combination of other characters. This is the first record of an articulated Lepidotes from the Santana Formation of the Araripe Basin.

The new pycnodont fishAnomoeodus pauciseriale is described. The single specimen consists of associated but disarticulated skeletal remains including the paired prearticulars, some skull elements, remains of the pectoral girdle and the vertebral column. It comes from the White Chalk Formation (Upper Cretaceous) of East Sussex near Lewes, England. The precise stratigraphic age and locality are not known. The specific identification is based on characters of the prearticular dentitions because the other skeletal remains are not diagnostic. In contrast to other species ofAnomoeodus, the new species is characterised by a combination of rather short prearticular dentitions with only four tooth rows, a comparable low number of medial teeth, and the absence of intercalated teeth between tooth rows.

Based on specimens from the Lower Cretaceous Tlayua Formation of Mexico, we describe a new genus and species of Halecomorphi, Cipactlichthys scutatus gen. et sp. nov, which exhibits several diagnostic characters such as the dermal bones and the scales with ganoin and highly ornamented by numerous tubercles and ridges; parietal slightly longer than wide with approximately the same length as the frontal; jaws extending far, below the posterior orbital margin, reaching the posterior third of the postorbital plate; maxilla with a convexly rounded posterior margin; pectoral fin margins slightly convex; first ray of pectoral fin very long, reaching the posterior edge of the pelvic fin; about 37 preural vertebrae and 7 Ural centra; a series of hypertrophied scales just posterior to the cleithrum; arrangement of flank scales with two rows of deep scales; a series of dorsal and ventral scutes forming the dorsal and ventral midline, between the dorsal and anal fins and the caudal fin. A phylogenetic analysis including two outgroups and eleven neopterygians confirmed the monophyly of the Holostei as well as the monophyly of the Halecomorphi, although this last clade is weakly supported. Cipactlichthys scutatus was hypothesised as the sister-group of the (Ionoscopiformes + Amiiformes).

The actinopterygian fish †Hemicalypterus weiri Schaeffer, 1967 is herein redescribed and rediagnosed based on new information collected from reexamination of museum specimens as well as examination of recently collected specimens from the Upper Triassic Chinle Formation of San Juan County, Utah, United States. †Hemicalypterus is distinguishable by its deep, disc-shaped compressed body; ganoid-scaled anterior half and scaleless posterior half; spinose, prominent dorsal and ventral ridge scales anterior to dorsal and anal fins; hem-like dorsal and anal fins with rounded distal margins; small mouth gape; and specialized, multicuspid dentition. This type of dentition, when observed in extant fishes, is often associated with herbivory, and †Hemicalypterus represents the oldest known ray-finned fish to have possibly exploited an herbivorous trophic feeding niche. A phylogenetic analysis infers a placement of †Hemicalypterus within †Dapediiformes, with †Dapediiformes being recovered as sister to Ginglymodi within holostean actinopterygians.