The Apsidoceratidae is a family of Middle and Upper Ordovician Barrandeocerina, (a suborder of tarphycerids), characterized by curved or coiled, smooth, transversely marked, or laterally costate shells, with a conspicuous hyponomic sinus. Early whorl sections tend to be subtriangular; become broader and dorsally impressed in closely coiled forms. Sutures are with lateral lobes in primitive forms but are without lateral lobes, but with ventral lobes in more advanced species with broader sections. Siphuncles are between the center and ventral margin, but not close to either.
Rousseau H. Flower, 1984. Bodeiceras; a New Mohawkian Oxycone, with Revision of the Older Barrandeocerida and Discussion of the Status of the Order. Journal of Paleontology v. 58, no.6, pp 1372–1379, Nov. 1984.
Walter C Sweet, 1964. Nautiloidea-Barrandeocerida; Treatise on Invertebrate Paleontology Part K Mollusca 3. Geological Society of America and University of Kansas Press.
August 29, 2023
apsidoceratidae, family, middle, upper, ordovician, barrandeocerina, suborder, tarphycerids, characterized, curved, coiled, smooth, transversely, marked, laterally, costate, shells, with, conspicuous, hyponomic, sinus, early, whorl, sections, tend, subtriangul. The Apsidoceratidae is a family of Middle and Upper Ordovician Barrandeocerina a suborder of tarphycerids characterized by curved or coiled smooth transversely marked or laterally costate shells with a conspicuous hyponomic sinus Early whorl sections tend to be subtriangular become broader and dorsally impressed in closely coiled forms Sutures are with lateral lobes in primitive forms but are without lateral lobes but with ventral lobes in more advanced species with broader sections Siphuncles are between the center and ventral margin but not close to either ApsidoceratidaeTemporal range Mid to Late OrdovicianScientific classificationKingdom AnimaliaPhylum MolluscaClass CephalopodaSubclass NautiloideaOrder TarphyceridaSuborder BarrandeocerinaFamily ApsidoceratidaeHyatt 1884Genera remaining in the Apsidoceratidae include Apsidoceras Charactoceras Charactocerina Deckeroceras Fremontoceras WilsonocerasChidleyenoceras previously assigned tentatively to the Apsidoceratidae has been reassigned Flower 1984 to the Plectoceratidae References EditRousseau H Flower 1984 Bodeiceras a New Mohawkian Oxycone with Revision of the Older Barrandeocerida and Discussion of the Status of the Order Journal of Paleontology v 58 no 6 pp 1372 1379 Nov 1984 Walter C Sweet 1964 Nautiloidea Barrandeocerida Treatise on Invertebrate Paleontology Part K Mollusca 3 Geological Society of America and University of Kansas Press Retrieved from https en wikipedia org w index php title Apsidoceratidae amp oldid 1165994346, wikipedia, wiki, book, books, library,
