Intejocerida
Intejocerida Temporal range: L -M Ordovician
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Scientific classification | |
Kingdom: | |
Phylum: | Mollusca |
Class: | |
Subclass: | Nautiloidea |
Order: | Intejocerida Balashov, 1960
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Intejocerida is the name given to a group of generally straight shelled
Diagnosis
Members of the Intejocerida are typically straight shelled with large siphuncles that vary in position from ventral to central, in which septal necks from very short to holochoanitic and connecting rings from moderately thick to apparently thin. Common to all, and the character by which the order was defined, are deposits within the siphuncle that have been described as longitudinal, radially arranged, calcareous lamellae.
Taxonomy
Taxonomic relations
Flower (1976) pointed out that not only does the Intejocerida contain two groups, one with
Derivation
Intejoceras and Bajkaloceras can be reasonably derived from the Baltoceratidae or less likely from the Troedssonellidae. Evencoceras, Rossoceras, and Padunoceras have their probable origin in the Proterocameroceratidae and are retained with the endocerids.
References
- Flower, R.H. 1976. Some Whiterock and Chazy Endoceroids. Part II, Mem.28; New Mexico Bureau of Mines and Mineral Resources, 1976.
- Teichert, C. 1964. Endoceratoidea. Treatise on Invertebrate Paleontology, Park K. Teichert & Moore (eds). Geological Society of America and Univ Kansas Press.