The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform
Valerie B. Morris - One of the best experts on this subject based on the ideXlab platform.
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Early development of coelomic structures in an Echinoderm Larva and a similarity with coelomic structures in a chordate embryo
Development Genes and Evolution, 2012Co-Authors: Valerie B. MorrisAbstract:Early coelomic development in the abbreviated development of the sea urchin Holopneustes purpurescens is described and then used in a comparison with coelomic development in chordate embryos to support homology between a single arm of the five-armed radial body plan of an Echinoderm and the single bilateral axis of a chordate. The homology depends on a positional similarity between the origin of the hydrocoele in Echinoderm development and the origin of the notochord in chordate development, and a positional similarity between the respective origins of the coelomic mesoderm and chordate mesoderm in Echinoderm and chordate development. The hydrocoele is homologous with the notochord and the secondary podia are homologous with the somites. The homology between a single Echinoderm arm and the chordate axis becomes clear when the aboral to oral growth from the archenteron in the Echinoderm Larva is turned anteriorly, more in line with the anterior–posterior axis of the early zygote. A dorsoventral axis inversion in chordates is not required in the proposed homology.
Shonan Amemiya - One of the best experts on this subject based on the ideXlab platform.
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Larval stages of a living sea lily (stalked crinoid Echinoderm)
Nature, 2003Co-Authors: Hiroaki Nakano, Taku Hibino, Yuko Hara, Shonan AmemiyaAbstract:The embryos and Larvae of stalked crinoids, which are considered the most basal group of extant Echinoderms1,2, have not previously been described. In contrast, much is known about the development of the more accessible stalkless crinoids (feather stars)3, which are phylogenetically derived from stalked forms4. Here we describe the development of a sea lily from fertilization to Larval settlement. There are two successive Larval stages: the first is a non-feeding auricularia stage with partly longitudinal ciliary bands (similar to the auricularia and bipinnaria Larvae of holothurian and asteroid Echinoderms, respectively); the second is a doliolaria Larva with circumferential ciliary bands (similar to the earliest Larval stage of stalkless crinoids). We suggest that a dipleurula-type Larva is primitive for Echinoderms and is the starting point for the evolution of additional Larval forms within the phylum. From a wider evolutionary viewpoint, the demonstration that the most basal kind of Echinoderm Larva is a dipleurula is consistent with Garstang's auricularia theory5 for the phylogenetic origin of the chordate neural tube.
Hiroaki Nakano - One of the best experts on this subject based on the ideXlab platform.
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Larval stages of a living sea lily (stalked crinoid Echinoderm)
Nature, 2003Co-Authors: Hiroaki Nakano, Taku Hibino, Yuko Hara, Shonan AmemiyaAbstract:The embryos and Larvae of stalked crinoids, which are considered the most basal group of extant Echinoderms1,2, have not previously been described. In contrast, much is known about the development of the more accessible stalkless crinoids (feather stars)3, which are phylogenetically derived from stalked forms4. Here we describe the development of a sea lily from fertilization to Larval settlement. There are two successive Larval stages: the first is a non-feeding auricularia stage with partly longitudinal ciliary bands (similar to the auricularia and bipinnaria Larvae of holothurian and asteroid Echinoderms, respectively); the second is a doliolaria Larva with circumferential ciliary bands (similar to the earliest Larval stage of stalkless crinoids). We suggest that a dipleurula-type Larva is primitive for Echinoderms and is the starting point for the evolution of additional Larval forms within the phylum. From a wider evolutionary viewpoint, the demonstration that the most basal kind of Echinoderm Larva is a dipleurula is consistent with Garstang's auricularia theory5 for the phylogenetic origin of the chordate neural tube.
Taku Hibino - One of the best experts on this subject based on the ideXlab platform.
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Larval stages of a living sea lily (stalked crinoid Echinoderm)
Nature, 2003Co-Authors: Hiroaki Nakano, Taku Hibino, Yuko Hara, Shonan AmemiyaAbstract:The embryos and Larvae of stalked crinoids, which are considered the most basal group of extant Echinoderms1,2, have not previously been described. In contrast, much is known about the development of the more accessible stalkless crinoids (feather stars)3, which are phylogenetically derived from stalked forms4. Here we describe the development of a sea lily from fertilization to Larval settlement. There are two successive Larval stages: the first is a non-feeding auricularia stage with partly longitudinal ciliary bands (similar to the auricularia and bipinnaria Larvae of holothurian and asteroid Echinoderms, respectively); the second is a doliolaria Larva with circumferential ciliary bands (similar to the earliest Larval stage of stalkless crinoids). We suggest that a dipleurula-type Larva is primitive for Echinoderms and is the starting point for the evolution of additional Larval forms within the phylum. From a wider evolutionary viewpoint, the demonstration that the most basal kind of Echinoderm Larva is a dipleurula is consistent with Garstang's auricularia theory5 for the phylogenetic origin of the chordate neural tube.
Yuko Hara - One of the best experts on this subject based on the ideXlab platform.
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Larval stages of a living sea lily (stalked crinoid Echinoderm)
Nature, 2003Co-Authors: Hiroaki Nakano, Taku Hibino, Yuko Hara, Shonan AmemiyaAbstract:The embryos and Larvae of stalked crinoids, which are considered the most basal group of extant Echinoderms1,2, have not previously been described. In contrast, much is known about the development of the more accessible stalkless crinoids (feather stars)3, which are phylogenetically derived from stalked forms4. Here we describe the development of a sea lily from fertilization to Larval settlement. There are two successive Larval stages: the first is a non-feeding auricularia stage with partly longitudinal ciliary bands (similar to the auricularia and bipinnaria Larvae of holothurian and asteroid Echinoderms, respectively); the second is a doliolaria Larva with circumferential ciliary bands (similar to the earliest Larval stage of stalkless crinoids). We suggest that a dipleurula-type Larva is primitive for Echinoderms and is the starting point for the evolution of additional Larval forms within the phylum. From a wider evolutionary viewpoint, the demonstration that the most basal kind of Echinoderm Larva is a dipleurula is consistent with Garstang's auricularia theory5 for the phylogenetic origin of the chordate neural tube.
