Chordates consist of three distinct animal groups: cephalochordates, urochordates (tunicates) and vertebrates. This review starts with a brief description of how the Phylum Chordata and its three subphyla were originally defined, and then discusses …

Chordates consist of three distinct animal groups: cephalochordates, urochordates (tunicates) and vertebrates. This review starts with a brief description of how the Phylum Chordata and its three subphyla were originally defined, and then discusses …

Chordates are divided into three subphyla: Vertebrata (fish, amphibians, reptiles, birds and mammals), whose notochords are replaced by a cartilaginous/bony axial endoskeleton and are cladistically and phylogenetically a subgroup of the clade Craniata (i.e. chordates with a skull); Tunicata or Urochordata (sea squirts, salps, and larvaceans ...

2024年1月1日 · Phylogenetic tree showing the relationships among deuterostomes and chordates. This tree was derived from morphological and molecular-phylogenetic evidence [e.g., in 3, 4]. Three hypothetical, reconstructed ancestors are shown along the backbone of the tree, at the bottom and correspond to the three nodes at the large black dots.

2000年4月25日 · Phylogenetic tree of the deuterostomes when sequences with similar evolutionary rates (16 taxa ≤0.12 substitutions per site) were analyzed with gambit. Key characters are mapped to the deeper nodes.

First, molecular phylogenetic analyses consistently place them at a basal position within the Chordata. Biologists, however, long predicted this relationship based on morphological analyses of the mobile, tadpole-like larvae of tunicates, which have most of the synapomorphies of chordates that are listed above, including a tail, notochord ...

This key phylogenetic position in the chordate tree (Figure 1), together with its slow evolving nature, both at the morphological and genomic levels, turn amphioxus into a unique and crucial ...

2005年11月9日 · In this article, we construct gene trees with invertebrate and vertebrate triple helical domain sequences to show that hemichordates and lancelets have at least one fibrillar collagen and that it is similar to type I and type II vertebrate collagens.

Cephalochordates, or amphioxus, share with tunicates and vertebrates the oldest common ancestor of chordates. This key phylogenetic position in the chordate tree , together with its slow evolving nature, both at the morphological and genomic levels, turn amphioxus into a unique and crucial animal for understanding the origin of chordate traits ...

2014年11月7日 · We propose that an evolutionary occurrence of tadpole-type larvae is fundamental to understanding mechanisms of chordate origin. Protostomes have now been reclassified into two major taxa, the Ecdysozoa and Lophotrochozoa, whose developmental pathways are characterized by ecdysis and trochophore larvae, respectively.