What is the largest living group of chordates?

Vertebrates are the largest group of chordates, with more than 62,000 living species.

What is the difference between annelids and chordates?

One major morphological difference between chordates and annelids or arthropods is the opposite orientation of the nerve cord and heart. A long-standing proposal is that the chordate axis evolved by inverting the body of an ancestor with the annelid/arthropod orientation.

How are animals grouped into phyla?

Animal phyla are classified according to certain criteria, including the type of coelom, symmetry, body plan, and presence of segmentation. Sponges (Porifera) have a primitive cellular level of organization and lack tissues and symmetry. They depend on a flow of water through the body to acquire food.

What are the 7 characteristics of chordates?

Phylum Chordata possesses the following characteristic features:

• Notochord. It is a longitudinal, cartilaginous rod running between the nerve cord and the digestive tract.
• Dorsal Nerve Cord.
• Pharyngeal Slits.
• Post anal Tail.
• Urochordata.
• Cephalochordata.
• Vertebrata.
• Lampreys.

What makes a Chordata a Chordata?

Characteristics of Chordata. Animals in the phylum Chordata share five key chacteristics that appear at some stage during their development: a notochord, a dorsal hollow (tubular) nerve cord, pharyngeal gill arches or slits, a post-anal tail, and an endostyle/thyroid gland (Figure 2).

Are Chordata multicellular or unicellular?

Members of the phylum Chordata are multicellular. This is because members of this phylum are animals, and animals are by definition multicellular.

How is phylum Chordata different from other animal phyla?

The four most prominent characteristics that distinguish chordates from species in all other phyla are the presence of a post-anal tail, a notochord, a dorsal, hollow nerve cord, and pharyngeal slits (also called gill slits).

Are chordates unicellular or multicellular?

Which is the largest phylum of animal kingdom?

arthropod, (phylum Arthropoda), any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes. About 84 percent of all known species of animals are members of this phylum.

Which among them is a characteristic of Chordata?

Animals in the phylum Chordata share four key features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

What is the characteristic of Chordata?

What phylum are Mollusca and Annelida in?

The phyla Mollusca and Annelida belong to a clade called the Lophotrochozoa, which also includes the phylum Nemertea, or ribbon worms (see: Features of the Animal Kingdom: phylogenetic tree of animals ).

What are the different types of annelids?

The annelids traditionally include the oligochaetes, which include the earthworms and leeches, the polychaetes, which are a marine group, and two other smaller classes.

Why are molluscs distinct from other invertebrates?

They are distinct from the Ecdysozoa (nematodes and arthropods) based on evidence from analysis of their DNA, which has changed our views of the relationships among invertebrates. Mollusca is the predominant phylum in marine environments, where it is estimated that 23 percent of all known marine species belong to this phylum.

How many species of molluscs are there?

Molluscs are amazingly diverse, with 110,000 named species, second only to the arthropods among all phyla of animals. Molluscs include such familiar creatures as clams, oysters, snails, and octopi. They share a distant common ancestor with the annelid worms, an evolutionary heritage suggested by