Sponges absent
Cnidarians not jointed (Aquatic organisms, all have tentacles with nematocysts - stinging cells, used to capture food.)
Roundworms absent (AKA nematodes are unsegmented, colorless and do not have appendages).
Annelids not jointed (With the exception of leeches, all annelids have chitonous hair-like structures projecting from their cuticle. These appendages fulfill different functions in different species.)
Mollusks not jointed (Invertebrates that lack hard appendages such as legs or antennae)
Arthropods jointed (the arthropods are the only invertebrates to have jointed appendages)
Echinoderms not jointed (Due to their radial symmetry, all echinoderms have appendages which point outward from the center of the body like the spokes on a wheel.)
and vertebrate jointed
<h2><u>Answer:</u></h2>
Amid the Ordovician Period, the outside of the earth was drastically unique in relation to it is today. About all life on earth was in the seas. The main land life was as exceptionally crude plants extremely close to the water line of the coasts, presumably greeneries and green growth and were of a non-vascular nature.
The Ordovician Period started with a noteworthy eradication called the Cambrian– Ordovician annihilation occasion, about 485.4 Mya (million years prior). It went on for around 42 million years and finished with the Ordovician– Silurian elimination occasions, about 443.8 Mya (ICS, 2004) which cleared out 60% of marine genera.
The timeframe that occurred 488 to 443 million years back. Amid the Ordovician time frame, some portion of the Paleozoic time, a rich assortment of marine life thrived in the tremendous oceans and the primary crude plants started to show up ashore—before the second biggest mass annihilation ever finished the period.
The Cerebellum is responsible for coordinating muscle movements and maintaining balance
