| Many annelids and molluscs share patterns of development in early embryonic stages. |
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| The anteriorly situated, eversible ciliated pits resemble nuchal organs of polychaete annelids. |
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| Arthropods, chordates and annelids are the three segmented phyla in the animal kingdom. |
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| Silurian ramphoprionid polychaete annelids, represented by their jaws, are described from extensive collections from Gotland, Sweden. |
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| In the complementary category of the protostomes, which includes annelids and arthropods, the blastopore develops into the mouth. |
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| In echiurans, sipunculans and in most polychaete annelids at least portions of the coelomic lining form the somatic and visceral musculature. |
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| Morphology places sipunculans with annelids and molluscs, and their mitochondrial genes relate them to annelids. |
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| Although mollusks, annelids, brachiopods, and sipunculans are closely related, the relationships between them are not well resolved. |
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| This is in contrast to organisms such as annelids and arthropods, in which the main nerve cord is ventral. |
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| We thought that leeches were one group and their sister group with the oligochaetes, earthworms and a variety of other aquatic annelids. |
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| The oligochaetes include earthworms and a group of related, mostly freshwater, species of annelids. |
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| In the complementary category, the protostomes, which includes annelids and arthropods, the blastopore develops into the mouth. |
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| These genomes have remarkably similar gene orders to previously published annelid genomes, suggesting that gene order is conserved across annelids. |
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| After examining the opening of these traces, it is tempting to assign their origin to the behavior of vermiform borers such as annelids, sipunculids, or phoronids. |
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| Most biologists are familiar with only a few of the approximately 40 extant animal phyla such as annelids, arthropods, molluscs, echinoderms and chordates. |
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| Furthermore, the micrognathozoans have two rows of multiciliated cells that forms a locomotory organ, similar to that in some gastrotrichs and interstitial annelids. |
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| The position and composition of the cells suggests that they are homologous to the gliointerstitial cell system of molluscs, sipunculans, annelids echiurans. |
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| The annelids include earthworms, polychaete worms, and leeches. |
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| Some information has been gathered on the expression of transcription factors associated with segmentation and regeneration in oligochaete annelids. |
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| The position and composition of these cells suggests that they are homologous to the gliointerstitial cell system of molluscs, sipunculans, annelids echiurans. |
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| Crustaceans, nematodes, trematodes, and polychaete annelids also serve as parasites. |
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| Neurons have been identified in a wide range of invertebrate species, including annelids, molluscs, nematodes and arthropods. |
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| Other zooplankton include cnidarians, ctenophores, chaetognaths, molluscs, arthropods, urochordates, and annelids such as polychaetes. |
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| Ninety-five percent majority rule consensus tree from Bayesian analyses of five concatenated genes from cirratuliform annelids, showing Swima n. gen. as part of Acrocirridae. |
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| Unlike in sea stars and sea urchins, annelids are not typical parasites. |
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| Annelids such as Serpulites are common fossils in some horizons. |
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