If you find a rock that has both a nautilus and a goniatite fossil, about hold is the rock? how do you know?

(this is some information within the lesson)
nautilus: 410 million years ago - present day
goniatite: 360 - 290 million years ago.

The rock will be old between 360 and 290 million years

Explanation:

If we have fossils from both nautilus and goniatite in the same rock layers, then we can look at the periods in which these two animals lived as a clue about the age of the rocks, thus the animals themselves as well. The nautilus occurs in the fossil records around 410 million years ago, but it is not extinct, in fact it still exists and it is one of the oldest species on the planet. The goniatite has had different story, as it existed for around 70 million years, between 360 and 290 million years ago. We can see from this information that these two organisms coexisted throughout the whole existence of the goniatite, thus the rocks can have an age of anywhere from 360 to 290 million years.