Proconodontida is an order of which originated in the late Cambrian (Furongian) and persisted partly through the Ordovician.
Proconodontida may be ancestral to another order, Belodellida.
Description
Cavidonts were simple conodonts, tending to maintain smooth and thin-walled elements with a
hyaline structure. They were often coniform (horn- or tooth-shaped) with a semi-symmetrical or elliptical cross-section.
The basal cavity was deeper than in early members of their
Sister group Conodonti. The apparatus is quinquimembrate at most (with five or fewer different element forms) and P elements are infrequent.
Lateral keels and subtle lines of serrations are frequently found in the hook-shaped elements of bellodelids, while other proconodonts rarely deviate from one or more basic conical structures.
Taxonomy
Cavidonti and its interrelationships were first established by Sweet (1988).
Many families and larger groups are
Paraphyly and not yet evaluated by cladistic analyses.
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Cavidonti Sweet, 1988
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Proconodontida Sweet, 1988
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Belodellida? Sweet, 1988
A different taxonomic arrangement, proposed by Dzik (1991), does not use Cavidonti as a grouping. Instead, it classifies proconodontids (families Proconodontidae, Cordylodontidae, and Fryxellodontidae) as members of the order
Panderodontida and the superfamily
Cordylodontacea. The order Belodellida is broken up and removed from their status as descendants of proconodontids. Bellodellidae and the component taxa of Dapsilodontidae (
Besselodus and
Dapsilodus) were moved into the superfamily
Panderodontacea, closer to
Panderodontidae and Strachanognathidae. Ansellidae is given a more distant placement among the
Prioniodontida.
A 1994 reevaluation of
Panderodus argued that Belodellidae may have close affinities to Panderodontida, while
Besselodus and
Dapsilodus are best classified within the order Protopanderodontida.
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The conodont apparatus as a food-gathering mechanism. Maurits Lindström, palaeontology, volume17, part 4, pages 729-744
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Taxonomy, Evolution, and Biostratigraphy of Conodonts from the Kechika Formation, Skoki Formation, and Road River Group (Upper Cambrian to Lower Silurian), Northeastern British Columbia. Leanne J. Pyle and Christopher R. Burnes, Canadian Journal of Earth Sciences, 38(10), pages 1387–1401, 2001,
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