A minute tube-dwelling colonial acorn worm found chiefly in deep water.
〔动〕羽鳃
Class Pterobranchia, phylum Hemichordata
Example sentencesExamples
The ciliary bands on the phoronid and brachiopod tentacles are upstream-collecting bands with separate cilia on monociliate cells just like those of larvae or adults of pterobranchs, echinoderms and enteropneusts.
Ax favors the Pharyngotremata hypothesis, but compiles evidence that not only the hemichordates but also the pterobranchs are paraphyletic grades.
Previously, hemichordates were thought to be paraphyletic, with enteropneusts (acorn worms) more closely related to chordates and pterobranchs closer to echinoderms.
The SSU data supported enteropneust paraphyly by placing acorn worms of the family Ptychoderidae as the sister to a group consisting of pterobranchs + acorn worms of the family Harrimaniidae.
There are two classes of hemichordate, the pterobranchs and the enteropneusts, which differ greatly in appearance and lifestyle.
Definition of pterobranch in US English:
pterobranch
nounˈterəˌbraNGk
Zoology
A minute tube-dwelling colonial acorn worm found chiefly in deep water.
〔动〕羽鳃
Class Pterobranchia, phylum Hemichordata
Example sentencesExamples
There are two classes of hemichordate, the pterobranchs and the enteropneusts, which differ greatly in appearance and lifestyle.
The ciliary bands on the phoronid and brachiopod tentacles are upstream-collecting bands with separate cilia on monociliate cells just like those of larvae or adults of pterobranchs, echinoderms and enteropneusts.
Ax favors the Pharyngotremata hypothesis, but compiles evidence that not only the hemichordates but also the pterobranchs are paraphyletic grades.
The SSU data supported enteropneust paraphyly by placing acorn worms of the family Ptychoderidae as the sister to a group consisting of pterobranchs + acorn worms of the family Harrimaniidae.
Previously, hemichordates were thought to be paraphyletic, with enteropneusts (acorn worms) more closely related to chordates and pterobranchs closer to echinoderms.