Biostratigraphy and taxonomy of polymerid trilobites of the Manuels River Formation (Drumian, middle Cambrian), Newfoundland, Canada Author Unger, Tanja Institut für Geowissenschaften, Universität Heidelberg, Im Neuenheimer Feld 234, 69120 Heidelberg (Germany) and Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, 44801 Bochum (Germany) tanja.unger@ruhr-uni-bochum.de Author Hildenbrand, Anne Institut für Geowissenschaften, Universität Heidelberg, Im Neuenheimer Feld 234, 69120 Heidelberg (Germany) Author Stinnesbeck, Wolfgang Institut für Geowissenschaften, Universität Heidelberg, Im Neuenheimer Feld 234, 69120 Heidelberg (Germany) Author Austermann, Gregor Institut für Geowissenschaften, Universität Heidelberg, Im Neuenheimer Feld 234, 69120 Heidelberg (Germany) text Geodiversitas 2022 2022-12-15 44 33 1051 1087 journal article 56143 10.5252/geodiversitas2022v44a33 0dfcd71d-bb24-4a0e-bc6d-15fbe04997d0 1638-9395 7477657 urn:lsid:zoobank.org:pub:4DA9802D-9500-4FD8-96F5-F4DD3BBF56A3 Genus Sao Barrande, 1846 Sao Barrande, 1846: 13 . — Type species: Sao hirsuta Barrande, 1846 , by original designation. Monadina – Barrande 1846: 19 . Monadella – Barrande 1847: 391 . Crithias – Hawle & Corda 1847: 17 . Tetracnemis – Hawle & Corda 1847: 17 . Goniacanthus – Hawle & Corda 1847: 18 . Enneacnemis – Hawle & Corda, 1847: 19 . Acanthocnemis – Hawle & Corda 1847: 20 . Acanthogramma – Hawle & Corda 1847: 20 . Endogramma – Hawle & Corda 1847: 21 . Micropyge – Hawle & Corda 1847: 21 . Selenosema – Hawle & Corda 1847: 23 . Staurogmus – Hawle & Corda 1847: 28 . DIAGNOSIS. —Wide cephalic border, strongly convex; glabella with three deep glabellar furrows and one longitudinal furrow; preglabellar field concave without ornamentation; cephalon with densely packed tubercles and small spines; thorax of 17 segments; pygidium short with one segment and one terminal piece (based on Harrington et al. 1959 ; Laibl et al. 2014 , with modifications). REMARKS Barrande (1852b) was the first to describe the different growth stages of Sao . He revised different genera previously introduced by Barrande (1846) and Hawle & Corda (1847) . Šnajdr (1958) further described the wide morphological range of ontogenetic stages, which is followed here. For further details see Šnajdr (1958) . Richter (1941) made a formal request to the International Commission on Zoological Nomenclature in favour of Sao Barrande, 1846 . He argued that the genus Sao Billberg, 1820 , was preoccupied by a Stomatopoda, but that the name was not used subsequently. While Monadina Barrande, 1846 was available, Sao was already a well-established name for the trilobite. Richter’s (1941) request was accepted and Sao Barrande, 1846 was given priority.