Fish remains (Elasmobranchii, Actinopterygii) from the Late Cretaceous of the Benue Trough, Nigeria

International audienceSelachian and ray-finned fish remains from various Late Cretaceous localities of Nigeria are described. Each locality has yielded only a very few specimens and the diversity is therefore very low. However, some taxa are recorded for the first time in Africa. The Ashaka locality in the Upper Benue Trough (northeastern Nigeria) has yielded a small but interesting late Cenomanian assemblage of microremains, including teeth of ''Carcharias'' amonensis, Rhombopterygia zaborskii sp. nov., Hamrabatis sp., ''Stephanodus'' sp., and a possible ionoscopiform. A large prearticular dentition coming from the early Turonian beds of this locality is assigned to the large pycnodontiform Acrotemnus, a poorly known genus here regarded as a senior synonym of Macropycnodon. In the Lower Benue Trough (southeastern Nigeria), several localities ranging in age from the late Cenomanian to the early Maastrichtian have yielded various widespread taxa such as Ptychodus, Scapanorhynchus, Squalicorax, Vidalamiinae indet., cf. Protosphyraena, and Eodiaphyodus. The seaway that occupied the Benue Trough during transgressive episodes (late Cenomanian-early Turonian and Maastrichtian) created opportunities for the dispersal of many marine fish taxa into new areas, such as the proto-South Atlantic

A new microvertebrate fauna from the Middle Hettangian (early Jurassic) of Fontenoille (Province of Luxembourg, south Belgium)

A Lower Jurassic horizon from Fontenoille yielding fossil fish remains can be dated to the Middle Hettangian Liasicus zone on the basis of the early belemnite Schwegleria and the ammonite Alsatites Iciqueus francus. Hybodontiform sharks are represented by Hybodus reticularis, Lissodus sp„ Polxacrodus sp, and Neoselachians by Synechodus paludinensis nov. sp. and Synechodus streitzi, nov. sp. Earlier reports of a scyliorhinid are not confirmed; teeth of similar morphology to scyliorhinids seem to be juvenile variants of 5. paludinensis. Chimaeriform remains include Squaloraja sp., the earliest occurrence of the genus. The Actinopterygian fauna is introduced, comprising a palaeonisciform cf. Ptxcholepis, a possible late perleidiform cf. Platysiagum, the dapediid semionotiforms Dapedium and cf. Tetragonolepis, the pycnodontiform Eomesodon, halecomorphs cf. Furidae or Ophiopsidae, pholidophoriforms and/or Leptolepididae, and actinistians. Lepidosaur remains are also present

A new genus and species for the amiiform fishes previously assigned to Amiopsis from the Early Cretaceous of Las Hoyas, Cuenca, Spain

The Mesozoic actinopterygian fish Amiopsis has been reported from three different localities in the Iberian Peninsula. Amiopsis woodwardi was described from the Berriasian–Valanginian of El Montsec (Lérida, Spain). Isolated vertebral centra referred to Amiopsis were found in the Barremian of Buenache de la Sierra (Cuenca, Spain). Finally, amiiform material from the Barremian of Las Hoyas (Cuenca, Spain) were reported as Amiopsis cf. A. woodwardi, due to the overall similarity with the species from El Montsec. Here a detailed anatomical description of the material from Las Hoyas is provided for the first time. The unique combination of characters seen in this taxon, some of which are not shared with Amiopsis but with more derived amiids, indicates that it represents a new taxon, which is here named Hispanamia newbreyi gen. nov., sp. nov

Phylogenetic Relationships of the Triassic Archaeosemionotus Deecke (Halecomorphi, Ionoscopiformes) from the 'Perledo Fauna'

The lagerstatten in the Monte San Giorgio have provided excellent fossils representing one of the most important windows to the marine life during the Triassic. Among these fossils, fishes are abundant and extraordinarily well preserved. Most of these fishes represent extinct lineages and were difficult to understand and classify during the early years after discovery. These difficulties usually led to a mixture of species under the same taxonomic name. This is the case of fishes referred to the genus Archaeosemionotus. The name bearing type of A. connectens, the type species of this genus, represents a basal halecomorph, but most other fishes referred to this genus represent basal ginglymodians. Therefore, we conducted this study to clarify the taxonomic status and phylogenetic relationships of A. connectens, which is a member of the family Furidae (Halecomorphi, Ionoscopiformes) representing the second cladistically supported evidence of ionoscopiforms in the Triassic and it is thus one of the two oldest reliable records of this group. Ionoscopiforms have a long stratigraphic range, though their fossil record is rather patchy. In our analysis, the sister taxon of Archaeosemionotus is Robustichthys from the Anisian of China, and they together form a clade with Furo, which is known from several localities ranging from the Early to the Late Jurassic. Other ionoscopiforms are so far known from the Kimmeridgian to the Albian and it is thus evident that recent efforts have concentrated on the later history of the group (Late Jurassic to Cretaceous). The phylogenetic relationships obtained for the Ionoscopiformes do not show a clear palaeobiogeographic pattern, but give important new insights into the origin, divergence date and early history of this clade

Anatomical differentiation of isolated scales of amiiform fishes (Amiiformes, Actinopterygii) from the Early Cretaceous of Las Hoyas (Cuenca, Spain)

Les écailles des poissons amiiformes sont plus différentes les unes des autres que ce qu’on avait précédemment affirmé. L’anatomie des écailles des trois taxons d’amiiformes du Crétacé inférieur (Barrémien) de Las Hoyas (Cuenca, Espagne) est décrite en détail. Les différences observées permettent la répartition des écailles isolées de cette localité entre ces trois taxons, ce qui permet de disposer d’un échantillonnage assez large, autorisant des études paléobiologiques et paléoécologiques.The scales of amiiform fishes are more different from each other than previously stated. The anatomy of the scales of the three amiiform taxa from the Early Cretaceous (Barremian) of Las Hoyas (Cuenca, Spain) is described in detail. The differences between them has allowed the segregation of isolated scales form the fossil record of this site into the three taxa, providing relatively large population samples that can be studied from a palaeobiological and palaeoecological point of view

Description of a new aspidorhynchid fish, <i>Belonostomus lamarquensis</i> sp. nov. (Halecostomi, Aspidorhynchiformes), from the continental Upper Cretaceous of Patagonia, Argentina

Some braincases, a predentary, a few vertebrae and scales of a new aspidorhynchid species, Belonostomus lamarquensis sp. nov., are described from the Upper Cretaceous (Campanian-Maastrichtian) Allen Formation of Patagonia, Argentina. The new species differs from the other Belonostomus species by its flank scales having an anterior smooth region separated by a vertical groove from a posterior region bearing a series of numerous and closely spaced subparallel ridges that end in a deeply crenulated posterior margin. The dermal bones are ornamented with ridges and tubercles, a rare character in Belonostomus. The endocranial bones are completely fused together, except the basisphenoid. Within the Belonostomus species, B. lamarquensis seems closely related to B. hooleyi from the English Lower Cretaceous, which also exhibits dermal bones with ridges and tubercles, and scales morphologically somewhat similar to those of B. lamarquensis

Aspectos Tafonômicos de Testudines da Formação Santana (Cretáceo Inferior),Bacia do Araripe, Nordeste do Brasil.

Araripe Basin is worldwide famous by diverse and exquisitely well preserved fossil assemblages in antana Formation. This lithostratigraphic unit is subdivided into three members: Crato, Ipubi and Romualdo. Up to date six species of turtles are known: Araripemys barretoi Price, 1973; Santanachelys gaffneyi, Hirayama,1998; Brasilemys josai Lapparent de Broin, 2000; Cearachelys placidoi Gaffney, Campos & Hirayama, 2001, Euraxemys essweini Gaffney, Tong & Meylan, 2006 and Caririemys violetae Oliveira & Kellner, 2007.Taphonomical features of turtles from Crato and Romualdo members are presents here. One specimen was examined in the Crato lagerstätte, (MN 4893-V) Araripemys sp. (partial skull, axial and apendicular skeleton). This exemplar is preserved in light-beige colored laminated limestone from the Crato Member. Three specimenswere analized (MN 6743-V, MN 6744-V and MN 6760-V) in the Romualdo lagerstätte, the two first are Araripemys barretoi specimens (shell and cervical vertebrae) and the later is a Cearachelys placidoi specimen (fragmented shell). They are preserved in calcareous nodules. No data of collection of these specimens areavailable, however are possible to infer on aspects of preservation of these exemplares, since that these are preserved in the original sedimentary matrix. All specimens have shown the surface of bones without abrasion, what it allows to infer these turtles as autocthonous

A new vertebrate assemblage from the matute formation of the Cameros Basin (Ágreda, Spain): implications for the diversity during the jurassic/cretaceous boundary

Altres ajuts: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.The Ribota site (Ágreda, Soria, Spain) is a new locality in the Matute Formation (Tithonian-Berriasian) composed of several carbonate layers, outstandingly rich in macrovertebrate remains. Fossils show an unusual replacement of the original bioapatite by quartz, and are found as positive reliefs protruding from lacustrine limestone beds. This type of conservation has allowed the identification of around one hundred vertebrate bone accumulations in an outcrop of more than 10 hectares. Osteichthyans (articulated partial skeletons, cranial material, and isolated postcranial bones and scales), crocodylomorphs (disarticulated cranial material, isolated teeth, vertebrae and osteoderms), turtles (partial carapaces and plastra, but also isolated plates) and pterosaurs (cranial and appendicular elements) have been identified. Around 80 specimens have been collected and a preliminary study of part of the collection (35 specimens) has allowed the identification of at least 5 different taxa: Halecomorphi indet., Neoginglymodi indet., Goniopholididae indet., Testudinata indet., and Pterodactyloidea indet. This new site represents one of the few sites from this time interval preserved in a fully lacustrine environment, so these vertebrate assemblages are unique and composed of different animals that presumably lived around and within the lake. They are dominated by aquatic and amphibian vertebrates and was formed by attrition in this lacustrine environment, possibly far from the lake shoreline. These macrovertebrate assemblages provide new data about the diversity in the faunal ecosystems from the Jurassic/Cretaceous transition of the Iberian Basin Rift System