The term tetrapod refers to four-limbed vertebrates, including humans. Elpistostege, from the Late Devonian period of Canada, is now considered the closest fish to tetrapods (4-limbed land animals), which includes humans.

A trend first observed in the evolution of the earliest tetrapods was B) feet with digits. .

The unique feature which all deuterostomes have in common is that the blastopore formed during gastrulation becomes the anus which would be consistent…

Why do skates and rays have flattened bodies, while sharks are torpedo shaped? Skates and rays need enlarged pectoral fins to help them stay level in turbulent water, while sharks do not.

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).

The major point to differentiate between chordates and non-chordates is that chordates have a spinal cord or backbone in their body structure whereas non-chordates are without backbone or notochord in their body structure.

In some chrodats notochord is replaced by vertebral colum in adult stage. Protochordates i.e., Urochordates and Cephalochordates don’t have a well developed spinal cord. Thus, the correct answer is option D.

Amphioxus

Chordate features. In chordates, four common features appear at some point during development: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. Humans are not chordates because humans do not have a tail.

Answer. Answer: Amphioxus also known as lancelet is a fish-like marine chordate. Unlike vertebrates, the dorsal nerve cord is not protected by bone but by a simpler notochord made up of a cylinder of cells that are closely packed to form a toughened rod.

A chordate (/ˈkɔːrdeɪt/) is an animal of the phylum Chordata (/kɔːrˈdeɪtə/). Chordates are divided into three subphyla: Vertebrata (fish, amphibians, reptiles, birds, and mammals); Tunicata or Urochordata (sea squirts, salps); and Cephalochordata (which includes lancelets).

Lobster is not a member of the phylum Chordata. It is a member of the phylum Arthropoda owing to the fact that lobster has jointed appendages, a segmented body and an exoskeleton while chordates have an endoskeleton.

The white tiger (Panthera tigris) is a chordate. The tiger is also from the class Mammalia, order Carnivora, and family Felidae, meaning it is a meat-eating cat.

Most chordates are animals with backbones. The white tiger (Panthera tigris) is a chordate. The tiger is also from the class Mammalia, order Carnivora, and family Felidae, meaning it is a meat-eating cat.

Carnivores

Tigers along with other chordates have a notochord, three germ layers, a hallow nerve cord and a tail projecting beyond the anus at some point of development. Tigers belong in this group because they rely heavily on animal tissue or meat for nutrition and energy.

As tigers have warm blood and hair (fur), and since they also give live birth, they are categorized under the Class Mammalia. They are meat eaters, therefore the classification under the order of Carnivora. Felidae, the family of cats.

Extant (living) subspecies

• t. altaica (Amur tiger or Siberian tiger)
• t. amoyensis (South China tiger) – possibly extinct in wild.
• t. corbetti (Indochinese tiger)
• t. jacksoni (Malayan tiger) – recognized as new subspecies in 2004.
• t. sumatrae (Sumatran tiger)
• t. tigris (Bengal tiger, a.k.a. Indian tiger)

Animal

India currently hosts the largest tiger population.