Ectenolites
Encyclopedia
Small, slender, cylindrial members of the Ellesmeroceratidae
that resemble small but proportionally narrower Ellesmeroceras. 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
and siphuncle
aligned.
The siphuncle in Ectenolites lies along the ventral side; is tubular, composed of short orthochoantic septal necks and thick concave connecting rings. The posterior portion is filled with irregularly spaced transverse diaphragms (dissepiments).
Ectenolites is one of two ellesmeroceratid genera known to have passed from the Late Cambrian into the Early Ordovician ( Gasconadian
= L Canadian
) and is found widespread in eastern North America from the Tribes Hill of New York to the Tanyard of Texas.
Ellesmeroceratidae
The Ellesmeroceratidae constitute a family within the cephalopod order Ellesmerocerida. They lived from the Upper Cambrian to the Lower Ordovician...
that resemble small but proportionally narrower Ellesmeroceras. 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
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
and siphuncle
Siphuncle
The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and Spirula...
aligned.
The siphuncle in Ectenolites lies along the ventral side; is tubular, composed of short orthochoantic septal necks and thick concave connecting rings. The posterior portion is filled with irregularly spaced transverse diaphragms (dissepiments).
Ectenolites is one of two ellesmeroceratid genera known to have passed from the Late Cambrian into the Early Ordovician ( Gasconadian
Gasconadian Stage
The Gasconadian Stage is the first stage of the Ordovician geologic period in North America and of the Lower Ordovician Canadian Epoch, coming immediately after the Late Cambrian Trempealeauan and preceding the middle Canadian Demingian Stage...
= L Canadian
Canadian Epoch
The Canadian is the Lower or Early Ordovician in North America. The term is common in the older literature and has been well understood for more than a century...
) and is found widespread in eastern North America from the Tribes Hill of New York to the Tanyard of Texas.
Uncited
- Flower R.H.1964, The Nautiloid Ordre Ellesmerocerida (Cephalopoda) Menoir 12, New Mexico Bureau of Mines and Mineral Resources, Socorro, NM
- Teichert, C 1964; Endoceratoidea, in The Treatise on Invertebrate PaleontologyTreatise on Invertebrate PaleontologyThe Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and...
Vol K, Nautiloidea. Teichert and Moore Eds; GSA and U of Kansas Press.