RT Journal Article
T1 Mass occurrence of planktic dendroid graptolite synrhabdosomes (Calyxdendrum) from the Early Ordovician Fezouata biota of Morocco
A1 Gutiérrez Marco, Juan Carlos
A1 Maletz, Jörg
AB The genus Calyxdendrum is here revised to include planktic dendroid graptolites from the Ordovician (Tremadocian to Sandbian). The mass occurrence of Calyxdendrum amicabilis n. sp. from the Fezouata biota represents one of the few occurrences of synrhabdosomes of dendroid morphology that have ever been discovered. Composite structures, formed from about four to six slender, conical tubaria of the species appear as umbrella-shaped synrhabdosomes. In these, the individual tubaria are connected by their short nemata forming an irregularly shaped proximal membrane. The species is found in the late Tremadocian Sagenograptus murrayi Biozone of the Bou Izargane section in the Ternata plain north of Zagora, Morocco. The mass occurrence is interpreted to represent planktic dendroid colonies transported by low velocity currents or moving actively into different water regions on a wide shallow shelf region. They settled in the “soupy” soft sediment, where they were subsequently compacted in the now lithified mudstone. Planktic dendroids of the genus Calyxdendrum are so far known exclusively from the peri-Gondwana region, but may prove to show a wider biogeographical distribution when better known.
PB Universitat de Barcelona
YR 2024
FD 2024-07-04
LK https://hdl.handle.net/20.500.14352/105997
UL https://hdl.handle.net/20.500.14352/105997
LA eng
NO Gutiérrez-Marco, J.C., Maletz, J., 2024. Mass occurrence of planktic dendroid graptolite synrhabdosomes (Calyxdendrum) from the Early Ordovician Fezouata biota of Morocco. Geologica Acta, 22.4, 1-23. DOI: 10.1344/GeologicaAct2024.22.4
NO Ministerio de Ciencia, Innovación y Universidades
NO IUGS-UNESCO
DS Docta Complutense
RD 6 abr 2025