The exact biological affinities of cornulitids are unknown (Fisher, 1962; Morris and Rollins 1971; Richards 1974; Gnoli 1992). Four genera Cornulites Schlotheim, 1820, Conchicolites Nicholson, 1872a, Cornulitella Nicholson, 1872b, Kolihaia Prantl, 1944, have been assigned to Cornulitidae (Fisher 1962). They have been affiliated to coelenterates (stromatoporoids, calcareous hydroids), fusulines, bryozoans, annelids and mollusks (Schlotheim 1820, Nicholson 1872a, Nicholson 1872b, Moore et al. 1952; La Rocque and Marple 1955; Fisher 1962; Bilnd 1972; Dzik 1991; Kriz et al. 2001). Dzik (1991) erected a new family Cornulitozoidae within the order Cornulitida (Bouãek 1964), containing two new genera, Cornulitozoon and Opatozoon, from Upper Ordovician and Silurian of Poland. Cornulitids range from Middle Ordovician to Mississippian (Fisher 1962; Richards 1974) and vary morphologically from single tubes to clusters of tubes cemented to each other and radiating outward in a fan-like manner. Cornulites shares most of characters with the lophoporates and was probably linked to tentaculitids and microconchids (Vinn and Mutvei, 2005).
Shell structures of Cornulites
Longitudinal section of the vesicular wall structure in Cornulites cf. proprius
Cross-section of the laminar shell with the pseudopunctae in C. cf. scalariformis
Juvenile specimens with the embryonic shells preserved in C. cf. flexuosus
Shell structures of Septalites
section of Septalites septatus
Vinn, 2005 shells with multiple septa; Silurian of
Simple prismatic structure and lamellar structure in the Septalites septatus Vinn, 2005 shell wall in longitudinal section.
© SEM photographs of cornulitids by Vinn & Mutvei
Reconstructions of cornulitids
Reconstruction of Cornulites shell as a lophophorate.