2007-12-09 10:26:06 · 4 answers · asked by Madison 3 in Science & Mathematics ➔ Earth Sciences & Geology
They are easily recognizable, they occur globally, and they lived in a (geologically) short period of time.
2007-12-09 10:33:26 · answer #1 · answered by Lady Geologist 7 · 0⤊ 0⤋
Trilobite Index Fossil
2016-12-17 09:18:47 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Not all types of trilobites are good index fossils. Certain species of trilobites are excellent index fossils though, and any will narrow the age of the rock it is found in to the Paleozoic Era.
Keep in mind that "trilobite" refers to a large group known as a Class. That is the same level as "Mammal", meaning one trilobite could be as different from another as you are from a bat, cow, or armadillo.
2007-12-09 10:44:46 · answer #3 · answered by Now and Then Comes a Thought 6 · 1⤊ 0⤋
There are lots of species that are globally wide spread, had short ranges ( a few million years counts as short when you're looking at Paleozoic animals), and they are easily identifiable.
2007-12-09 11:29:06 · answer #4 · answered by kiddo 4 · 0⤊ 0⤋