The Animal 2023 twist that features a shocking surprise

Animal, any of a group of multicellular eukaryotic organisms thought to have evolved independently from the unicellular eukaryotes. Animals differ from other multicellular eukaryotes, the plants and the fungi, in morphology and physiology in that animals evolved muscles, which allow them to be mobile. Animal - Anatomy, Physiology, Behavior: Hydrostatic skeletons are the most prevalent skeletal system used by animals for movement and support. The locomotory/feeding system of animals is the heart of their adaptation to their physical and biotic environments. Animal - Multicellular, Heterotrophic, Eukaryotes: A characteristic of members of the animal kingdom is the presence of muscles and the mobility they afford. The muscles that distinguish animals from plants or fungi are specializations of the actin and myosin microfilaments common to all eukaryotic cells. Animal - Diversity, Classification, Evolution: The diverse appearance of animals is mostly superficial; the bewildering variety of known forms can be assorted among a mere half-dozen basic body plans. While parazoans lack clearly defined tissues and organs, the two coelenterate phyla (Cnidaria and Ctenophora) advanced in complexity beyond the parazoans by developing incipient tissues. Explore animals and nature; animal facts and stats, mammals, marsupials, birds, insects, reptiles, dinosaurs, megafauna, fossils, environment, plants, trees, bacteria ...

Animal cells are bounded by a membrane composed chiefly of fatlike molecules and protein. Green plants and algae make their own food and are therefore called producers. With the aid of the green substance called chlorophyll, they use the energy in sunlight to change carbon dioxide and water into carbohydrates and other food materials. Animal - Evolution, Paleontology, Adaptation: Animals first appeared in the Ediacaran Period (about 635 million to 541 million years ago), as soft-bodied forms such as coelenterates. Vertebrates are not known until the Ordovician, when the first of a series of mostly heavily armoured jawless fishes appeared. Animal - Classification, Taxonomy, Phylogeny: Because the aschelminths have not been studied adequately by modern methods, there is no consensus on their classification. The classification in this article is based on morphological work carried out in the late 1980s and remains to be tested by RNA sequence studies and other comparisons.