''Ectenolites'' is a genus of small, slender, cylindrical Ellesmeroceratids that resemble ''

Ellesmeroceras ''Ellesmeroceras'' is the type genus for the Ellesmeroceratidae, a family of primitive nautiloid cephalopods, that is characterized by its small, generally compressed, gradually expanded, orthoconic shell, found in Lower Ordovician marine sedime ...

'' but are smaller and proportionally narrower. Septa, as typical for ellesmerocerids, are close spaced with shallow lobes on either flank. The body chamber is proportionally long, the shell itself slightly compressed. The dorsal side at the beginning of the shell, opposite the aperture and body chamber, is strongly convex so to produce a sense of endogastric curvature with the

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

and

siphuncle The siphuncle is a strand of biological tissue, tissue passing longitudinally through the mollusc shell, shell of a cephalopod mollusc. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the li ...

aligned.Flower R.H.1964, The Nautiloid Order Ellesmeroceratida (Cephalopoda). Memoir 12, New Mexico Bureau of Mines and Mineral Resources, Socorro, NM The siphuncle in ''Ectenolites'' lies along the ventral side; is tubular, composed of short orthochoanitic septal necks and thick concave connecting rings. The posterior portion is filled with irregularly spaced transverse diaphragms. ''Ectenolites'' is one of two ellesmeroceratid genera known to have passed from the Late Cambrian into the Early OrdovicianChen, J. Y.; Teichert, C.(1983). Cambrian Cephalopods. Geology v. 11 pp. 647–650 Nov 1983 ( Gasconadian) and is found widespread in North America from the Tribes Hill of New York to the Tanyard of Texas.

References

{{Taxonbar, from=Q5333977 Ellesmerocerida Prehistoric cephalopod genera Cambrian molluscs of North America Ordovician animals of North America Cambrian first appearances Early Ordovician extinctions Cambrian genus extinctions