Megafauna de Invertebrados Paleozoicos y Mesozoicos

MANCEÑIDO, M.O.; DAMBORENEA, S.E.

Geología y Recursos Naturales de la Provincia de Rio Negro

IX° Congreso Geológico Argentino

Lugar: Buenos Aires; Año: 1984; p. 413 - 465

Present knowledge of Palaeozoic and Mesozoic megainvertebrate fossils from Rio Negro Province allows the recognition of the following faunal associations: a) Clarkeia antisiensis -Heterorthella d. freitana Association: occurs in Sierra Grande Formation and implies a Silurian (Wenlockian) age. b) Weyla sp. -Chlamys textoria Association: restricted to Piltriquitron Formation, corresponds to the Lower JurassiC, i.e. Pliensbachian (-Toarcian?) . c) Isognomon nanus -Anditrigonia subnodosa Association: typical of the Ortiz Formation, may be correlated with Upper TithonianBerriasian. d) Diplodon amphitheatri Association: confined to lower units within the Neuquen Group, presumably of pre-Maastrichtian, Upper Cretaceous, age. e) Neocorbicula pehuenchensis -Lioplacodes wichmanni Association: tnmsicional in nature between Neuquen and Malargtie Groups, can therefore be assigned to Maastrichtian (-CamClarkeia antisiensis -Heterorthella d. freitana Association: occurs in Sierra Grande Formation and implies a Silurian (Wenlockian) age. b) Weyla sp. -Chlamys textoria Association: restricted to Piltriquitron Formation, corresponds to the Lower JurassiC, i.e. Pliensbachian (-Toarcian?) . c) Isognomon nanus -Anditrigonia subnodosa Association: typical of the Ortiz Formation, may be correlated with Upper TithonianBerriasian. d) Diplodon amphitheatri Association: confined to lower units within the Neuquen Group, presumably of pre-Maastrichtian, Upper Cretaceous, age. e) Neocorbicula pehuenchensis -Lioplacodes wichmanni Association: tnmsicional in nature between Neuquen and Malargtie Groups, can therefore be assigned to Maastrichtian (-CamWeyla sp. -Chlamys textoria Association: restricted to Piltriquitron Formation, corresponds to the Lower JurassiC, i.e. Pliensbachian (-Toarcian?) . c) Isognomon nanus -Anditrigonia subnodosa Association: typical of the Ortiz Formation, may be correlated with Upper TithonianBerriasian. d) Diplodon amphitheatri Association: confined to lower units within the Neuquen Group, presumably of pre-Maastrichtian, Upper Cretaceous, age. e) Neocorbicula pehuenchensis -Lioplacodes wichmanni Association: tnmsicional in nature between Neuquen and Malargtie Groups, can therefore be assigned to Maastrichtian (-CamIsognomon nanus -Anditrigonia subnodosa Association: typical of the Ortiz Formation, may be correlated with Upper TithonianBerriasian. d) Diplodon amphitheatri Association: confined to lower units within the Neuquen Group, presumably of pre-Maastrichtian, Upper Cretaceous, age. e) Neocorbicula pehuenchensis -Lioplacodes wichmanni Association: tnmsicional in nature between Neuquen and Malargtie Groups, can therefore be assigned to Maastrichtian (-CamDiplodon amphitheatri Association: confined to lower units within the Neuquen Group, presumably of pre-Maastrichtian, Upper Cretaceous, age. e) Neocorbicula pehuenchensis -Lioplacodes wichmanni Association: tnmsicional in nature between Neuquen and Malargtie Groups, can therefore be assigned to Maastrichtian (-CamNeocorbicula pehuenchensis -Lioplacodes wichmanni Association: tnmsicional in nature between Neuquen and Malargtie Groups, can therefore be assigned to Maastrichtian (-Cam . paman?).. f) Diplodon bodenbenderi -Paleoanculosa ameghiniana Association: characteristic of part of Malargtie Group, in continental facies, apparently referable to the Maastrichtian (-Danian?). g) Eubaculites ootacodensis -Pterotrigonia windhauseniana Association: also present in Malargtie Group, without reaching the topmost units, occurs in marine facies and indicates a Maastrichtian age. Since this is just a preliminary scheme, it should be pointed out that: Diplodon bodenbenderi -Paleoanculosa ameghiniana Association: characteristic of part of Malargtie Group, in continental facies, apparently referable to the Maastrichtian (-Danian?). g) Eubaculites ootacodensis -Pterotrigonia windhauseniana Association: also present in Malargtie Group, without reaching the topmost units, occurs in marine facies and indicates a Maastrichtian age. Since this is just a preliminary scheme, it should be pointed out that: Eubaculites ootacodensis -Pterotrigonia windhauseniana Association: also present in Malargtie Group, without reaching the topmost units, occurs in marine facies and indicates a Maastrichtian age. Since this is just a preliminary scheme, it should be pointed out that: be pointed out that: I) Differences among the last named associations are in a good deal due to environinental factors, so they might be partly overlapping in time and space. Differences among the last named associations are in a good deal due to environinental factors, so they might be partly overlapping in time and space. II) It seemed preferable not to include any further Palaeozoic or Mesozoic association of the same kind, because, at present, insufficient evidence renders such procedure unwarranted. This does not prevent additional associations to be inserted where needed if soundly supported by future studies. if soundly supported by future studies. ?).. f) Diplodon bodenbenderi -Paleoanculosa ameghiniana Association: characteristic of part of Malargtie Group, in continental facies, apparently referable to the Maastrichtian (-Danian?). g) Eubaculites ootacodensis -Pterotrigonia windhauseniana Association: also present in Malargtie Group, without reaching the topmost units, occurs in marine facies and indicates a Maastrichtian age. Since this is just a preliminary scheme, it should be pointed out that: Diplodon bodenbenderi -Paleoanculosa ameghiniana Association: characteristic of part of Malargtie Group, in continental facies, apparently referable to the Maastrichtian (-Danian?). g) Eubaculites ootacodensis -Pterotrigonia windhauseniana Association: also present in Malargtie Group, without reaching the topmost units, occurs in marine facies and indicates a Maastrichtian age. Since this is just a preliminary scheme, it should be pointed out that: Eubaculites ootacodensis -Pterotrigonia windhauseniana Association: also present in Malargtie Group, without reaching the topmost units, occurs in marine facies and indicates a Maastrichtian age. Since this is just a preliminary scheme, it should be pointed out that: be pointed out that: I) Differences among the last named associations are in a good deal due to environinental factors, so they might be partly overlapping in time and space. Differences among the last named associations are in a good deal due to environinental factors, so they might be partly overlapping in time and space. II) It seemed preferable not to include any further Palaeozoic or Mesozoic association of the same kind, because, at present, insufficient evidence renders such procedure unwarranted. This does not prevent additional associations to be inserted where needed if soundly supported by future studies. if soundly supported by future studies.