Dictyonema (graptolite)

Dictyonema Temporal range:
File:Dendrograptidae - Dictyonema retiforme.JPG
Dictyonema retiforme from Early Silurian of Canada (425 myo)
Scientific classification
Kingdom:	Animalia
Phylum:	Hemichordata
Class:	† Graptolithina
Order:	† Dendroidea
Family:	† Dendrograptidae
Genus:	Dictyonema Hall, 1851
Synonyms
Dictyodendron Westergård 1909 Dictyograptus Hopkinson 1875 Airograptus Ruedemann 1916 Damesograptus Jahn 1892 Nephelograptus Ruedemann 1947

Dictyonema is a genus of dendroid graptolites in the order Dendroidea.

Fossil record

Fossils of Dictyonema are found from the Upper Cambrian to the Devonian (age range: from 488.3 to 383.7 million years ago.). They are known from various localities in Europe, North America, South America, China and Morocco.

Description

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.

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