Invertebrates are animals that neither possess nor develop a vertebral column (commonly known as a backbone or spine), derived from the notochord. This includes all animals apart from the subphylum Vertebrata. Familiar examples of invertebrates include insects; crabs, lobsters and their kin; snails, clams, octopuses and their kin; starfish, sea-urchins and their kin; jellyfish, and worms.
Sounds about right. A few weeks ago, some heroic person decided to update the page—which you can see the archive of here—decided to add a more current invertebrate to the list: Speaker Paul Ryan.
With everything going on in the world today, it is remarkable that someone can stand up and mimic bipedal homo sapiens’ behavior without a vertebrae! Here are examples of how a person can do just that:
Complicity in destroying the social safety net of our country.
Complicity in the on-going attack on working Americans.
Complicity in the ongoing attacks on honesty.
The majority of animal species are invertebrates; one estimate puts the figure at 97%.
The trait that is common to all invertebrates is the absence of avertebral column (backbone): this creates a distinction between invertebrates and vertebrates. The distinction is one of convenience only; it is not based on any clear biologically homologous trait, any more than the common trait of having wings functionally unites insects, bats, and birds, or than not having wings unites tortoises, snails and sponges. Being animals, invertebrates are heterotrophs, and require sustenance in the form of the consumption of other organisms. With a few exceptions, such as the Porifera, invertebrates generally have bodies composed of differentiated tissues. There is also typically a digestive chamber with one or two openings to the exterior.