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What does Agnatha mean?

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What does Agnatha mean?

1 : a superclass or other division of Vertebrata comprising those without jaws — compare gnathostomata. 2 : a group of carnivorous air-breathing snails without jaws.

What does Agnatha mean in Latin?

Origin. From modern Latin Agnatha, from a-‘without’ + Greek gnathos ‘jaw’.

What does Agnatha spell?

agnathan, (superclass Agnatha), any member of the group of primitive jawless fishes that includes the lampreys (order Petromyzoniformes), hagfishes (order Myxiniformes), and several extinct groups.

What are the characteristics of agnatha?

Key Features of Agnatha

  • Jaws are absent.
  • Paired fins are generally absent.
  • Early species had heavy bony scales and plates in their skin, but these are not present in living species.
  • In most cases the skeleton is cartilaginous.
  • The embryonic notochord persists in the adult.
  • Seven or more paired gill pouches are present.

What are the characteristics of Agnatha?

What is the origin of the word Agnatha?

Origin: From Agnatha, from ἀ- + γνάθος. Agnatha is a superclass of jawless fish in the phylum Chordata, subphylum Vertebrata. The group excludes all vertebrates with jaws, known as gnathostomes. The agnathans as a whole are paraphyletic, because most extinct agnathans belong to the stem group of gnathostomes.

Is the Agnatha a jawless or paraphyletic fish?

Agnatha is a superclass of jawless fish in the phylum Chordata, subphylum Vertebrata. The group excludes all vertebrates with jaws, known as gnathostomes. The agnathans as a whole are paraphyletic, because most extinct agnathans belong to the stem group of gnathostomes.

What kind of body does an Agnatha have?

All living and most extinct Agnatha do not have an identifiable stomach or any appendages. Fertilization and development are both external. There is no parental care in the Agnatha class. The Agnatha are ectothermic or cold blooded, with a cartilaginous skeleton, and the heart contains 2 chambers.

How are fertilization and development in the Agnatha class?

Fertilization and development are both external. There is no parental care in the Agnatha class. The Agnatha are ectothermic or cold blooded, with a cartilaginous skeleton, and the heart contains 2 chambers.