Since the adoption of the Bill of Rights â the first 10 amendments to the Constitution, ratified in 1791 â only 17 amendments have cleared the hurdles necessary to be codified in the nation's founding document, the last of which was ratified in 1992.
Other examples are leeches and sand worms. Believe it or not, 75% of the entire animal kingdom is right here in phylum Arthropoda! Arthropods include all insects, spiders and crustaceans so it is a HUGE phylum. Arthropods are known for having protective exoskeletons and segmented legs. Some have 6 legs, 8 legs or even 10 legs but none of them have a backbone.
Phylum Arthropoda. This is the most extensive phylum in the animal kingdom. It is composed of 3/4 of all known species. Approximately 900,000 species of arthropods have been recorded. Included are spiders, scorpions, ticks, mites crustaceans, millipedes, centipedes, insects, and some others.There is an extended fossil record.Arthropods are eucoelomate protostomes with well-developed organ systems.Most species have combined or fused somites and appendages into functional groups called tagmata for specialized purposes. Although all types-carnivorous, omnivorous, and symbiotic-occur, the majority are herbivorous.In diversity of ecological distribution, the arthropods have no rivals.pproximately 900,000 species of arthropods have been recorded. Included are spiders, scorpions, ticks, mites crustaceans, millipedes, centipedes, insects, and some others. There is an extended fossil record. Arthropods are eucoelomate protostomes with well-developed organ systems.