A new Late Jurassic halecomorph fish from the marine Vaca muerta formation, Argentina, southwestern Gondwana

The knowledge of Mesozoic fish faunas of the Southern Hemisphere is still inadequate; the diversity and evolution of the Late Jurassic marine ichthyofaunas of Argentina remain unclear. One fish recovered from the Tithonian levels of the Los Catutos Member of the Vaca Muerta Formation, southwestern Argentina was considered a “caturid-like” halecomorph for almost 30 years. Recently, it was proposed that it could belong to the Pachycormiformes. A thorough comparative anatomical study of the material is conducted to test whether it could be included in †Caturidae or †Pachycormidae. The specimen is assigned to †Caturidae as a new genus and species: †Catutoichthys olsacheri (http://zoobank.org/urn:lsid:zoobank.org:act: 6884876C-075C-433B-90B7-74187FC04C26, registered on 1 June 2016). The new taxon is based on a unique character combination, three of which are exclusive to †Catutoichthys olsacheri among caturids–diplospondylous vertebral column with triangular basidorsals and welldeveloped and fan-shaped basiventrals; neural and haemal spines strongly inclined to the body axis at an angle of 14°; a large number of infrahaemals; rounded amioid-type scales with an unornamented free field. The new taxon provides anatomical information useful for further understanding the anatomy and evolution of caturid fishes.Facultad de Ciencias Naturales y Muse

A new Late Jurassic halecomorph fish from the marine Vaca muerta formation, Argentina, southwestern Gondwana

The knowledge of Mesozoic fish faunas of the Southern Hemisphere is still inadequate; the diversity and evolution of the Late Jurassic marine ichthyofaunas of Argentina remain unclear. One fish recovered from the Tithonian levels of the Los Catutos Member of the Vaca Muerta Formation, southwestern Argentina was considered a “caturid-like” halecomorph for almost 30 years. Recently, it was proposed that it could belong to the Pachycormiformes. A thorough comparative anatomical study of the material is conducted to test whether it could be included in †Caturidae or †Pachycormidae. The specimen is assigned to †Caturidae as a new genus and species: †Catutoichthys olsacheri (http://zoobank.org/urn:lsid:zoobank.org:act: 6884876C-075C-433B-90B7-74187FC04C26, registered on 1 June 2016). The new taxon is based on a unique character combination, three of which are exclusive to †Catutoichthys olsacheri among caturids–diplospondylous vertebral column with triangular basidorsals and welldeveloped and fan-shaped basiventrals; neural and haemal spines strongly inclined to the body axis at an angle of 14°; a large number of infrahaemals; rounded amioid-type scales with an unornamented free field. The new taxon provides anatomical information useful for further understanding the anatomy and evolution of caturid fishes.Facultad de Ciencias Naturales y Muse

Sistemática y relaciones biogeográficas de los peces del Titoniano (Jurásico Tardío) de la Cuenca Neuquina de Argentina

Tesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Gouiric Cavalli, Soledad. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

New pycnodontiform fishes (Actinopterygii, Neopterygii) from the Early Cretaceous of the Argentinian Patagonia

Here we describe new pycnodontiform fish material recovered from the marine Agrio Formation (lower Valanginian–lower Hauterivian) of the Neuquén 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.Fil: Gouiric Cavalli, Soledad. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Remirez, Mariano Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Kriwet, Jürgen. University of Vienna; Austri

Los peces del Jurásico Tardío (Titoniano) de la Cuenca Neuquina, estado actual del conocimiento e implicancias biogeográficas

Durante el Jurásico ocurrieron dos de las radiaciones más importantes de vertebrados pisciformes: la de los Neoselachii y la de los Teleostei. De hecho, se constituyó en un momento de diversificación y origen de muchos de los grandes grupos actuales. Históricamente, la mayor parte de los estudios sobre ictiofaunas marinas jurásicas fueron llevados a cabo en el Hemisferio Norte. Es por ello que el conocimiento de la ictiofauna marina jurásica en el Hemisferio Sur no es tan vasto como en el Hemisferio Norte, a excepción de los peces del Oxfordiano de Chile. Durante el Jurásico Temprano (Toarciano), el Proto-Pacífico habría estado en contacto con el Tethys europeo a través del Corredor Hispánico con lo cual la dispersión de numerosas formas de vertebrados e invertebrados fue posible. En Argentina, los peces marinos jurásicos se encuentran representados en localidades de las provincias de Mendoza y Neuquén emplazadas dentro de la Cuenca Neuquina en dos formaciones (Picún Leufú y Vaca Muerta). Los peces hallados fueron estudiados preliminarmente por Dolgopol de Saez, quien distinguió nuevas especies fundadas en material pobremente preservado. Estas designaciones fueron cuestionadas posteriormente. Actualmente, nuevos materiales han sido colectados. Entre los que se pueden mencionar osteictios (teleósteos, catúridos, paquicórmidos, semionótidos, aspidorrínquidos y posibles celacántidos) y condrictios (batomorfos e hidodóntidos). El presente trabajo tiene como objetivo dar a conocer los avances realizados en el estudio de los peces marinos del Jurásico de Argentina haciendo inferencias sobre las posibles rutas de migración y/o dispersión usadas por los peces.Facultad de Ciencias Naturales y Muse

New pycnodontiform fishes (Actinopterygii, Neopterygii) from the Early Cretaceous of the Argentinian Patagonia

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 Muse

First record of elasmobranchs from the Lower Cretaceous of Argentina (Neuquén Basin)

The material reported herein comes from the Lower Cretaceous Agrio Formation (Neuquén Basin, west-central Argentina). These fishes dwelled in a Pacific Ocean embayment in southwestern Gondwana before the establishment of the Andean Cordillera. The material consists of an incomplete dorsal fin spine of the widespread Hybodontoidea clade (from upper Valanginian beds) and a partial tooth of one of the earliest known lamniforms (from upper Hauterivian beds).Facultad de Ciencias Naturales y Muse

Atlantocerus, a new genus of lungfish from the upper cretaceous of South America and Africa

Fil: Cione, Alberto Luis. Departamento Paleontología Vertebrados, Museo de La PlataFil: Gouiric-Cavalli, Soledad. Departamento Paleontología Vertebrados, Museo de La PlataFil: Goin, Francisco Javier. Departamento Paleontología Vertebrados, Museo de La PlataFil: Poiré, Daniel Gustavo. Departamento Paleontología Vertebrados, Museo de La Plat

Atlantoceratodus a new genus of lungfish from the upper Cretaceous of South America and Africa

The only previously known material of “Ceratodus” iheringi Ameghino, 1898 (the hoiotype, a tooth píate) was collected by Carlos Ameghino along with other marine and freshwater fossils in the “Piso Shehuenense” in Pari Aike, Río Shehuen, Southern Patagonia. The material was figured but not described. Fortunately, the hoiotype was preserved in the Museo de La Plata. The bearing beds are presently included in the Mata Amarilla Formation which is considered Cenomanian-Coniasian in age. Additional lungfish material from the Southern part of Mendoza and Río Negro provinces was erroneously reponed by several authors to this species.In the present contribution, based on about 200 complete and fragmentary tooth plates from the type locality, we describe and diagnose the species “Ceratodus ” iheringi and a new genus, Atlantoceratodus. The species appears to be only known in the type area. Atlantoceratodus iheringi most closely resembles “Ceratodus " madagascariensis Priem, 1924 from the upper Cretaceous (Campanian) of Madagascar and we suggest that both species pertain to the same genus.Facultad de Ciencias Naturales y Muse

Atlantoceratodus a new genus of lungfish from the upper Cretaceous of South America and Africa

The only previously known material of “Ceratodus” iheringi Ameghino, 1898 (the hoiotype, a tooth píate) was collected by Carlos Ameghino along with other marine and freshwater fossils in the “Piso Shehuenense” in Pari Aike, Río Shehuen, Southern Patagonia. The material was figured but not described. Fortunately, the hoiotype was preserved in the Museo de La Plata. The bearing beds are presently included in the Mata Amarilla Formation which is considered Cenomanian-Coniasian in age. Additional lungfish material from the Southern part of Mendoza and Río Negro provinces was erroneously reponed by several authors to this species.In the present contribution, based on about 200 complete and fragmentary tooth plates from the type locality, we describe and diagnose the species “Ceratodus ” iheringi and a new genus, Atlantoceratodus. The species appears to be only known in the type area. Atlantoceratodus iheringi most closely resembles “Ceratodus " madagascariensis Priem, 1924 from the upper Cretaceous (Campanian) of Madagascar and we suggest that both species pertain to the same genus.Facultad de Ciencias Naturales y Muse