Study this image of a geologic time scale.

\begin{tabular}{|c|c|c|c|}
\hline ERA & PERIOD & \begin{tabular}{l}
MILLIONS OF \\
YEARS AGO
\end{tabular} & KEY EVENTS \\
\hline \multirow{2}{}{Cenozoic} & Quaternary & & \multirow{5}{}{\begin{tabular}{l}
Humans evolve \\
Extinction of \\
Dinosaurs
\end{tabular}} \\
\hline & Tertiary & & \\
\hline \multirow{3}{}{Mesozoic} & Cretaceous & & \\
\hline & Jurassic & & \\
\hline & Triassic & & \\
\hline \multirow{6}{
}{Paleozoic} & Permian & & \multirow{3}{}{\begin{tabular}{l}
Permian mass \\
extinction
\end{tabular}} \\
\hline & \begin{tabular}{|l|}
Carboniferous \\
\end{tabular} & & \\
\hline & Devonian & & \\
\hline & Silurian & & Invertebrates \\
\hline & Ordovician & & become common \\
\hline & Cambrian & & \multirow{4}{
}{\begin{tabular}{l}
Earliest life
\end{tabular}} \\
\hline Precambrian & \multirow{3}{}{\begin{tabular}{l}
Also known \\
as \\
Precambrian
\end{tabular}} & \multirow{3}{
}{ - 3500 - } & \\
\hline Archean & & & \\
\hline Proterozoic & & & \\
\hline
\end{tabular}

How long ago did invertebrates become common on Earth?

A. 1.6 million years ago
B. 132 million years ago
C. 410 million years ago
D. 520 million years ago



Answer :

To determine how long ago invertebrates became common on Earth, we'll analyze the geologic time scale provided in the table.

1. Identify the era and period where the event occurred:
- Era: Paleoroic
- Period: Selungn
- Key Event: Invertebrates become common

2. Compare the given event with the provided options:
- 1.6 million years ago
- 132 million years ago
- 410 million years ago
- 520 million years ago

Given that the event of invertebrates becoming common took place during the Selungn period of the Paleoroic era, the correct time frame, according to the available information, is:

410 million years ago.

Therefore, invertebrates became common on Earth 410 million years ago.