These colonial organism are characterized by a conical, net-like structure. The colonies (known as rhabdosomes) are branched and may vary from almost discoidal to almost cylindrical. They were stationary planktonic suspension feeders.[1][2]
Species
†Dictyonema macgillivrayi (Hall 1899)
†Dictyonema pulchellum (Hall 1899)
†Dictyonema retiforme (Hall 1843)
Bibliography
Bulman, O. M. B. 1970. Graptolithina with sections of Enteropneusta and Pterobranchia. In
Treatise on Invertebrate Paleontology Part V 2nd ed. (C. Teichert, ed.) pp. V1-V149. The Geological Society of America, Inc.: Boulder (Colorado), and the University of Kansas: Lawrence (Kansas).
Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1-167.
Jaanusson, V. 1979. Ordovician. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A136-A166. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
Kozłowski, R. 1948. Les graptolithes et quelques nouveaux groupes d’animaux du Tremadoc de la Pologne. Palaeontologica Polonica 3: I-XII, 1-235.
Rudolf Ruedemann - Graptolites of North America – Geological Society of America