CO'NODONTS (from Gk. Kij POS, knows, cone Mas, °don•, tooth). Minute fossil teeth of uncertain affinities, found in rocks of Ordovician to Permian age of North America and Europe. They are very small, shilling objects, with more or less extended bases, from which arise one or many slender, sharp, short or long denticles. They thus vary in form from conical to pectinate according to the number and length of the denti des. The material of which they consist is red, brown, or white ealeite or phosphate of lime. Associated with the tooth-like forms are minute plates of the same material, that probably be longed to the same organisms. Conodonts were first described by Pander, in 1856, from the lowest fossiliferous (Cambrian) rocks of Russia, and were by him regarded as fish-teeth. Since then they have been found in England, the United States. and Canada, and various opinions have been expressed regarding their affinities. New berry described a number from the Carboniferous shales of Ohio, and compared them to the teeth of myxinoid fishes. Other authors have con
sidered them to be the spines of crustacea or the lingual teeth of naked mollusks. These opinions are all less well supported by facts than is that of Zittel and Holum, that conodonts are the teeth of annelids allied to the Nereidie. In the same rocks' with eonodonts are often found jaws of annelids, described as Prioniodus, Polygnathus, etc. Consult: Pander, Monographic der lossilen Fische des silurisehen Systems (Saint Peters burg, 1856) ; Hinde, "On Conodonts from the Chazy and Cincinnati Groups," etc.. Quarterly Journal Geological Society, vol. xxxv. London, 1879) ; Newberry, Paleontology of Ohio, vol. ii. (Columbus, Ohio. 1875) ; Zittel and Rohon, "Ueber Conodonten," Sitzungsberichte der konig lieh -bayerisehen Akademie der Wissensehaften (Munich, 1886). See WORM, FOSSIL; ANNTJLATA.