Contact The NJ State Museum
Mailing Address:
NJ State Museum
PO Box 530
Trenton, NJ 08625

Museum & Auditorium Galleries:
205 West State Street
Trenton, NJ

Tel: (609) 292-6464 (recorded message)



Episode 2: How Do You Know Where The Fossils Are?


Welcome back to the New Jersey State Museum’s Ask the Experts Video Learning Library, where we’re digging into some of the most common questions people ask paleontologists about what we do and how we do it. 

In the last episode, we talked about how paleontologists decide where on Earth’s surface to look for dinosaurs – that is, how we find rocks that are the right age, and the right type. We’re on the hunt for dinosaurs, so we’re looking for sedimentary rocks that are between 65 and 230 million years old.

But once you know generally where to look, how do you decide exactly where to start digging?  How do we know, in the middle of this whole vast terrain, exactly where to dig?  Well, why don’t we start digging into those questions right now?

The short answer is that we don’t know where the fossils are. First we have to find them.  And the process of finding fossils is called “prospecting”. Prospecting is just a fancy word for walking around slowly while looking at the ground. And what you’re looking for are small bits of fossilized bone or teeth that are weathering out of the ground. Now, it could take days or weeks before you find even a single scrap of bone. Or, you could really lucky and be in a place like this, where fossils are all around us!  Why don’t we take a look.

As you may have seen while we were prospecting, almost every fossil you find will just be a single, isolated piece of a bone or two. Very rarely will you find the big bones or more of the skeleton. That could be because part of the skeleton may have already washed away or maybe it was never fossilized in the first place. Or, there could be a good bit more fossil just slightly hidden from view in the ground.  Here though, we have a nice accumulation of bone and we’re going to collet this. But where do we look from here?  Well, up there is a good place to start! 

Weathering and erosion are the major forces in places like this, sculpting and carving the land into the spectacular and rugged formations you see around me.  Those same forces also work on the fossils within the rocks.  Weathering breaks the fossils into smaller pieces, and erosion and gravity pull those broken bits downhill.  So, if you’re very lucky, you can follow those broken bits like a trail of breadcrumbs to a skeleton still lying hidden somewhere in the hillside. 

So it looks like some of those bones we collected down there come from these bones that are still in the ground. What do you have Alana? Hi Jason, we have a bone right there, we think it may be a rib. We also have some plant material right here, and these pinkish white bits are some bi-valves we think thy might be clams. So because of that we think its possible this might have been a lake environment. We also found Triceratops teeth, which appear to be in pretty good condition. Yes, they look great.

So this may not look like much, but this is how some of paleontology’s greatest discoveries come about. We started with just a few scraps of bone downhill, and they led us here to a few more bones still in the rock; but there’s no way of knowing just how much of the skeleton may still be in the mountain. 

As you may have seen while I was prospecting, it didn’t take very long just to find things.  Many of those “things” were just broken pieces of fossil, or even pieces of modern plants or the skeletons of little animals that live out here. Many others times they’re just rocks that look like fossils. People often ask us “How do you tell the difference between rocks and fossils?” To many people, the fossil looks just like the rock. Well, there actually are a lot of different tricks we use to help us tell the difference almost every time. But we’d better dig into that question next time.  Until then, as always, thanks for joining us, and always keep digging!