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Noun1.Heterostraci - extinct group of armored jawless fishes or fish-like vertebrate; taxonomy is not clear
animal order - the order of animals
order Ostracodermi, Ostracodermi - extinct group of armored jawless vertebrates; taxonomy is not clear
heterostracan - extinct jawless fish with the anterior part of the body covered with bony plates; of the Silurian and Devonian
References in periodicals archive ?
Because of new information discovered by the fossil turnaround,Elliott believes that this fossil and several similar ones had been inappropriately assigned to an order of fish, Heterostraci, whose members have only a single set of tube-like openings that run to the gills.
The Cyathaspididae constitute a family within the Heterostraci in which the carapace consists of a dorsal and ventral shield including branchial and suborbital plates.