The most primitive multicellular animal is generally considered to be the sponge or Porifera. Sponges are simple animals that lack true tissues and organs. They are filter feeders that live in aquatic environments and have a basic body structure consisting of specialized cells that work together for basic functions such as feeding and reproduction.
The most primitive multicellular animals are thought to be sponges, also known as poriferans. Sponges belong to the phylum Porifera and are considered the simplest and most ancient of all multicellular animals. They lack true tissues and organs, and their body is organized into pores, channels, and chambers that allow water to flow through them. Sponges are also sessile, meaning they are permanently attached to a substrate and do not move like other animals. Because of their simple body structure and lack of specialized cells, sponges are often considered the most primitive multicellular animals.
