The Ordovician Graptolite Genus Paraglossograptus Mu

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Abstract
Summary: The lacinia in Paraglossograptus Mu is shown to consist of four ladder-like networks which are independent of each other and have no direct connection with spinose thecal apertural processes. The lacinial networks are positioned at the corners of the quadrangular rhabdosome as in Paraglossograptus ? sp. of Whittington & Rickards, which is described here as Paraglossograptus proteus (Harris & Thomas). Paraglossograptus etheridgei (Harris, 1924), the important Ordovician zone fossil, together with P. typicalis Mu and P. latus Hsü, are considered junior synonyms of Reteograptus tentaculatus J. Hall, 1865. P. tentaculatus (J. Hall, 1865), is regarded here as the type species of Paraglossograptus Mu. Detailed comparisons are made between P. tentaculatus and the stratigraphically younger P. proteus (Harris & Thomas), and with Glossograptus holmi Bulman, a species in some ways intermediate between Paraglossograptus and Glossograptus Emmons.