• species
  • Seventeen metazoan phyla contain freshwater species, and only 11 phyla comprise terrestrial animals. (springer.com)
  • Two phyla (freshwater Micrognathozoa and terrestrial Onychophora) possess no marine species. (springer.com)
  • We report newly observed details of the morphology and ontogeny of this species. (rroij.com)
  • Developmental biology with a true deep-time component-Palaeo-Evo-Devo-demands for fossil species with reconstructable ontogenies, so-called fossilized ontogenies. (rroij.com)
  • The phylotypic stage is the most conserved stage of embryogenesis between species within a phylum. (wikipedia.org)
  • It is the point in which developing embryos of species in the same phylum display maximal similarity. (wikipedia.org)
  • Recently, molecular tools have been used to identify the phylotypic period based on the developmental stage that displays maximal conservation of gene expression or minimal gene sequence divergence between species within a phylum. (wikipedia.org)
  • Recent papers refer to the phylotypic period, or the phylotypic stage, as a period of maximal similarity between species within each animal phylum. (wikipedia.org)
  • In terms of taxonomic hierarchy, characters in the embryo are formed in top-to-bottom sequence, first from those of the largest and oldest taxon, the phylum, then in turn class, order, family, genus, and finally species. (wikipedia.org)
  • The phylum has a wide range of body forms, including the flattened, deep-sea platyctenids, in which the adults of most species lack combs, and the coastal beroids, which lack tentacles and prey on other ctenophores by using huge mouths armed with groups of large, stiffened cilia that act as teeth. (wikipedia.org)
  • genus
  • A subsequent study suggested a placement of the genus in its own phylum, Xenoturbellida, as a deuterostome clade and sister group to the Ambulacraria. (wikipedia.org)
  • Protostomia
  • The monophyly of Xenacoelomorpha soon became established, but its position as either a basal bilaterian clade or a deuterostome remained unresolved until very recently, when two new studies, with increased gene and taxon sampling, again placed Xenoturbella as the sister group of Acoelomorpha within Xenacoelomorpha, and placed Xenacoelomorpha as sister to Nephrozoa (Protostomia plus Deuterostomia), and therefore the basalmost bilaterian phylum. (wikipedia.org)
  • animals
  • Brachiopods, phylum Brachiopoda, are a group of lophotrochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. (wikipedia.org)
  • commonly known as comb jellies) is a phylum of invertebrate animals that live in marine waters worldwide. (wikipedia.org)
  • However, genomic studies have suggested that the neurons of Ctenophora, which differ in many ways from other animal neurons, evolved independently from those of the other animals, and increasing awareness of the differences between the groups has persuaded more recent authors to classify the two as separate phyla. (wikipedia.org)
  • Animal
  • The data shows that all the animal phyla have similar genes and that there aren't very many genes whose origins can be traced to the Cambrian. (blogspot.com)
  • His [Meyer's] case against current scientific explanations of the relatively rapid appearance of the animal phyla rests on the claim that the origin of new animal body plans requires vast amounts of novel genetic information coupled with the unsubstantiated assertion that this new genetic information must include many new protein folds. (blogspot.com)
  • genes
  • In fact, our present understanding of morphogenesis indicates that new phyla were not made by new genes but largely emerged through the rewiring of the gene regulatory networks (GRNs) of already existing genes (1). (blogspot.com)