Geologic Age
Also: geologic time, age, stage
A specimen's place in deep time, named on the geologic time scale (eon, era, period, epoch, age). For Lowcountry shark teeth this usually means the Oligocene or Miocene, tens of millions of years ago.
Geologic age is where a fossil sits in Earth's deep-time calendar. Geologists divide all time, from longest to shortest, into eons, eras, periods, epochs, and ages, anchored by the rock record and the species found in it. When we say a Lowcountry shark tooth is Oligocene, we are naming an epoch tens of millions of years old.
The hierarchy, briefly
| Unit | Rough scale | Example |
|---|---|---|
| Period | Tens to hundreds of millions of years | Paleogene |
| Epoch | Several to tens of millions of years | Oligocene |
| Age (stage) | A few million years | Chattian |
Why age matters to a collector
Age frames the whole story: it tells you which sharks were alive, why a cusplet might or might not be present, and whether an identification is plausible. It is read from the formation a fossil came from, which is why naming the formation matters so much. Our guide to South Carolina's fossil formations connects each local unit to its age.