Answer: Armored fish
Explanation:
The earliest known fossil vertebrates were heavily armored fish discovered fish in rocks from the Ordovician period.
The fossils shows the path from the early aquatic life to the vertebrates, vertebrates to mammals.
The fossils shows that it is vertebrate and are the oldest known fossil ever known. The fossils of the animals and plants helps to known the behavior of the past time and based on that research and study is done.
Disaccharide is formed when glucose and fructose are combined
Most of legumes have symbiotic, nitrogen-fixing<span> bacteria, that live in structures called "</span>root nodules"<span>. </span>