Pre-Hirnantian (latest Ordovician) benthic community assemblages: controls and replacements in a siliciclastic-dominated platform of the eastern Anti-Atlas, Morocco.
17 pages; International audience; Lower-middle Ashgill sedimentary strata from the Mediterranean region have recorded a key episode of temperate-to-cold water, carbonate productivity predating the onset of the Hirnantian glaciation. The latitudinal position of the Moroccan margin of North Gondwana during Ashgill should have been adequate for the recorded development of carbonate factories. However, carbonate productivity was neither homogeneous nor laterally persistent, as documented in the eastern Anti-Atlas. Whereas in the Erfoud area, the bryozoan-dominated limestones of the Ashgill Khabt-el-Hajar Formation indicate the intensive activity of carbonate factories, these were dramatically r…
New trepostomate bryozoans from the Upper Ordovician of Morocco and the temperature influence on zooid size
AbstractNew Upper Ordovician trepostomate bryozoans from the eastern Anti-Atlas of Morocco have been identified. They have been collected from the lower and intermediate units of the Khabt-el-Hajar Formation, late Katian in age, representing, respectively, bryozoan-pelmatozoan meadows with siliciclastic input, degraded by wave activity in a mid-ramp setting, and outer-ramp environments with marly substrates. Ten species of the generaCyphotrypa,Calloporella,Diplotrypa,Parvohallopora,Dekayia, andAostiporaare described. Of them, three species are new:Cyphotrypa regularisJiménez-Sánchez,Parvohallopora cystataJiménez-Sánchez, andAostipora elongataJiménez-Sánchez. Univariate statistical analyses …
Trepostomate bryozoans from the upper Katian (Upper Ordovician) of Morocco: gigantism in high latitude Gondwana platforms.
AbstractA study of the Upper Ordovician trepostomate bryozoans belonging to the families Amplexoporidae and Monticuliporidae, from the eastern Anti-Atlas of Morocco, is presented here. They occur in the marly to fine-grained limestone, intermediate unit of the Khabt-el-Hajar Formation, late Katian in age, representing outer-ramp depositional environments. They inhabited the highest paleolatitude known for a bryozoan fauna during the Ordovician, estimated at more than 65–70ºS. A total of 11 species of the generaAnaphragma,Atactoporella,Homotrypa,Monotrypa,Monticulipora, andPrasoporaare described. Three species are already known from the equatorial-tropical paleocontinents of Baltica, Laurent…
Data from: Trepostomate bryozoans from the upper Katian (Upper Ordovician) of Morocco: gigantism in high latitude Gondwana platforms
A study of the Upper Ordovician trepostomate bryozoans belonging to the families Amplexoporidae and Monticuliporidae, from the eastern Anti-Atlas of Morocco, is presented here. They occur in the marly to fine-grained limestone, intermediate unit of the Khabt-el-Hajar Formation, late Katian in age, representing outer-ramp depositional environments. They inhabited the highest paleolatitude known for a bryozoan fauna during the Ordovician, estimated at more than 65–70ºS. A total of 11 species of the genera Anaphragma, Atactoporella, Homotrypa, Monotrypa, Monticulipora, and Prasopora are described. Three species are already known from the equatorial-tropical paleocontinents of Baltica, Laurenti…
Data from: New Trepostomate bryozoans from the upper Ordovician of Morocco and the temperature influence on zooid size
New Upper Ordovician trepostomate bryozoans from the eastern Anti-Atlas of Morocco have been identified. They have been collected from the lower and intermediate units of the Khabt-el-Hajar Formation, late Katian in age, representing, respectively, bryozoan-pelmatozoan meadows with siliciclastic input, degraded by wave activity in a mid-ramp setting, and outer-ramp environments with marly substrates. Ten species of the genera Cyphotrypa, Calloporella, Diplotrypa, Parvohallopora, Dekayia, and Aostipora are described. Of them, three species are new: Cyphotrypa regularis Jiménez-Sánchez, Parvohallopora cystata Jiménez-Sánchez, and Aostipora elongata Jiménez-Sánchez. Univariate statistical anal…