Vertebrates

eukaryotic domain

The lancelets, also known as amphioxus, are a group of 32 species of marine creatures in shallow waters. Despite giving good insight into the origination of vertebrate life, they are not themselves vertebrates, because their 'spine' is not a true spine.

they sorta look like a bony tail. It looks a bunch of bent donuts all joined together

cervical, thoracic, lumbar, and sacral curvature.

Certainly, cold-blooded vertebrates can freeze to death. Few organisms can survive if their body temperature falls below freezing. The expanding ice crystals inside cells will break the cell membranes, killing the cell, and if the cells die, the multi-cellular organism also dies. Some animals get around this problem by using a kind of anti-freeze inside their cells.

Vertebrates are animals with a backbone,

so some vertebrates live in water (e.g. fish) but others live on land (e.g. cows).

An exoskeleton.

A dogfish, all fish actually, is an invertebrate.

Oxygen is transported in the blood by binding to hemoglobin in red blood cells, forming oxyhemoglobin. Carbon dioxide is transported in the blood in three forms: dissolved in plasma, as bicarbonate ions, and bound to hemoglobin. These gases are exchanged in the lungs during respiration.

Some examples of vertebrates that can float in water include ducks, alligators, and hippos. These animals have adaptations such as buoyant bodies or air-filled structures that allow them to stay afloat on the water's surface.

i do not have a clue :S

• They are covered with tough, dry scales.

• They're ectothermic [they control their body temperature through external means]

• Breathe with lungs throughout their lives.

• Have a three-chambered heart with a ventricle that is partially divided.

• They produce amniotic eggs covered with a leathery shell, most oviparous, some ovoviviparous.

Neither those two groups only refer to animals!

Vertebrates are animals with backbones, invertebrates don't have backbones.

Evolutionary condition when everywhere was surrounded by water. when the condition changed than sea water is going to boil and these animals get more fast metabolic reaction. we know when metabolic reaction going to fast then required oxygen quantity is more high and when water boils then mixed oxygen quantity is very less (due to hydrogen bonds breaking).

Now the time when early vertebrates came out from water because the condition would be changed there are direct oxygen in atmosphere from that they fulfill required oxygen.

vertebrates

Tetrapods

The eagle is, as are all birds.

Unusual vertebrates are those species that display unique adaptations or characteristics that set them apart from typical vertebrate forms. Examples include the axolotl, a neotenic salamander that retains its larval features throughout its life, and the platypus, a mammal that lays eggs and has a bill resembling that of a duck. Other examples include the seahorse, where males carry and give birth to young, and the lamprey, a jawless fish with a distinct parasitic lifestyle. These species highlight the incredible diversity and adaptability of vertebrate life.

Yes, we have a spine.

...yes.

they are vertebrates..

all mammals mostly, so horses, snakes, whales, fishes, zebras, cows, pigs, and alot of other animals your welcome =D

It's an invertebrate because it does not have a backbone.

The fact that jawless fish retain the notochord during development suggests that jawed vertebrates have evolved to develop without the notochord. This indicates that the notochord is an ancestral characteristic that has been lost or modified in the evolutionary lineage leading to jawed vertebrates.