AnimaliaacceptedgenusAccepted
Trigonodictya

Trigonodictya

Ulrich, 1893

GBIF:196202560

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Descriptions(5)

COMPARISON
Ernst, Andrej, Carrera, Marcelo G. (2022): A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas 44 (20): 563-601, DOI: 10.5252/geodiversitas2022v44a20
DIAGNOSIS. — Branched colonies, sometimes with lateral ridgelike expansions. Mesotheca straight to sinuous in longitudinal section, locally zigzag in transverse section, containing median rods. Autozooecia arranged in straight rows, subrectangular to subrhomboidal in transversal section of endozone, locally separated by extrazooecial vesicles in endozone, separated by extrazooecial stereom in exozone, rectangular in deep tangential section, becoming oval on the colony surface. Basal diaphragms straight to slightly curved. Extrazooecial skeletal deposits common, consisting of laminar and vesicular portions. Vesicular structures common in inner exozones, locally in endozones. Laminar stereom commonly with dark zones, longitudinally aligned, locally with indistinct mural styles. Autozooecial boundaries distinct, delineated laterally by continuous dark zones. Monticules absent.
Ernst, Andrej, Carrera, Marcelo G. (2022): A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas 44 (20): 563-601, DOI: 10.5252/geodiversitas2022v44a20
Trigonodictya Ulrich, 1893 differs from Pachydictya Ulrich, 1882 in regular arrangement of autozooecia in straight rows.
Ernst, Andrej, Carrera, Marcelo G. (2022): A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas 44 (20): 563-601, DOI: 10.5252/geodiversitas2022v44a20
OCCURRENCE. — Middle Ordovician – Middle Silurian; Europe, North and South America.
Ernst, Andrej, Carrera, Marcelo G. (2022): A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas 44 (20): 563-601, DOI: 10.5252/geodiversitas2022v44a20
TYPE SPECIES. — Pachydictya conciliatrix Ulrich, 1886 by subsequent designation (Ulrich 1893). Decorah Shale, Middle Ordovician; United States (Minnesota).
Ernst, Andrej, Carrera, Marcelo G. (2022): A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas 44 (20): 563-601, DOI: 10.5252/geodiversitas2022v44a20

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Source Information

A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera

checklist

This dataset contains the digitized treatments in Plazi based on the original journal article Ernst, Andrej, Carrera, Marcelo G. (2022): A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas 44 (20): 563-601, DOI: 10.5252/geodiversitas2022v44a20

ABSTRACT

Nineteen bryozoan species belonging to 18 genera are described from the La Pola Formation (Sandbian, Upper Ordovician) of Argentine Precordillera. Two trepostome genera each with one new species, respectively, are new: Albardonia bifoliata n. gen., n. sp. and Argentinopora robusta n. gen., n. sp. Five more species are new: a cystoporate Xenotrypa argentinensis n. sp., two trepostomes Heterotrypa enodis n. sp. and Nicholsonella spinigera n. sp., as well as two ptilodictyines Pseudostictoporella simplex n. sp. and Chazydictya ornata n. sp. The studied fauna shows some connection with Laurentia and Baltica on the species level and is similar to Siberia on the generic level. Furthermore, the generic composition of the La Pola fauna is similar to contemporary faunas of Las Aguaditas and Las Plantas formations of the Argentine Precordillera. The described fauna comes from mixed carbonate-siliciclastic deposits and represents a largely para-autochthonous association, with few autochthonous elements.The bryozoan growth forms indicate shallow shelf conditions. Bryozoans are associated with brachiopods, red algae, and echinoderms indicating heterozoan community typical for temperate to cool water environments with high primary production.

MOTS CLÉS

Ordovicien,

Sandbien,

environnement d’eau

froide,

Bryozoa,

paléogéographie,

paléoécologie,

genres nouveaux,

espèces nouvelles.

Ernst A, Carrera M G, admin (2022). A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera. Geodiversitas. Checklist dataset https://doi.org/10.15468/22hb3y accessed via GBIF.org on 2026-06-16.

CC0Published 6/16/2022View dataset
GBIF Usage Key
196202560
Dataset Key
f8f165f8-1b6b-4639-b139-c47e48485949
Origin
source
Backbone Key
4857317
Taxon ID
865C87FDFFBBFFF939B1FBA14BE7F803.taxon
Last Crawled
6/9/2026
Last Interpreted
6/9/2026