Difference between lizard and newt

The circulatory system is a three-chambered heart and two circles of blood circulation. Due to the imperfection of the system, mixed fluid circulates through the vessels. Newts are cold-blooded.

The digestive system ends in a cloaca, and the teeth serve to contain, not for the primary crushing of prey. The excretory organs are the trunk kidneys, ureters and the bladder, which has an outlet to the cloaca. Metabolic products are released not only by a special system, but also through the skin.

Newts are dioecious, most of them have external fertilization. The female lays the ripe eggs only in the water, after which the male fertilizes them. All amphibians in their ontogeny go through four stages: egg-egg, larva-tadpole, metamorphosis and an adult.

Newts are typical predators feeding on insects, their larvae, invertebrates, with a pronounced craving for cannibalism.

Conclusions TheDifference.ru

  1. The time of the appearance of animals on the planet is different. Newts evolved earlier - in the Devonian - Paleozoic, lizards later, in the Carboniferous period of the same era.
  2. Lizards have more species and have a wider range on Earth than newts.
  3. Skin covers are different. Lizards have scales, while newts have smooth, mucus-covered skin.
  4. Lizards are able to shed their tail on their own, but newts are not.
  5. Different number of sections of the axial ridge. In lizards - 5, in newts - 4. In the latter there is no thoracic region.
  6. The skull of lizards is more ossified than that of newts. The brain of the former is sauropsid, in amphibians it is ichthyopsid.
  7. Reptile respiration is carried out by the lungs; in newts, the lungs, gills and skin are involved in the process.
  8. In a reptile, the kidneys are pelvic, in amphibians, the kidneys are of the trunk.
  9. In reptiles, fertilization is internal, in amphibians - external.
  10. Ovoviviparity and oviposition are noted in lizards. Newts can reproduce only in the aquatic environment, and their offspring are subject to metamorphosis.
  11. Lizards have a higher level of development than newts.