Digging/hunting General Question

[Oneradtek202]

When hunting for fossils, if you are finding all the same type of fossils is there any way to find different ones within that era? ( such as deeper in the base rock etc)

[Cris]

You might be able to research and find a different geological formation similar in age nearby if the place you're hunting isn't producing what you want....or maybe moving to a new site nearby in the same formation could do the job.

For me, if I hunt a site a few times and I'm just finding the same common stuff, I just move on to a nearby site.

[jpc]

Sometimes the rarer stuff shows up once for every hundred 'same old things'.

Edited August 5, 2015 by jpc

[FossilDAWG]

Each outcrop is a (very incomplete) record of the environment that occurred at that spot at various points in time. The species that were present will depend on the environment as well as on taphonomic events (were fossils buried quickly, or exposed to scavengers and movement by currents?). Also, animals are generally patchily distributed in space. Therefore, each outcrop will contain a sampling of the total fauna present in a formation. Think of it like sticking a pin in a map, then going to look at the plants and animals that are found right at that exact point. Stick your pin into another spot a few miles away and go look there. Will you find exactly the same plants and animals, in the same proportions? Examining other outcrops, even if they are of the same formation, may reveal different species. Also, outcrops incorporate the element of time. The time represented by a rock formation can be hundreds of thousands to a few million years, and so the species found at one level may be different from species found at a different level.

So, your best chance of finding a lot of new material for your collection would be to collect at new sites.

However, you should also keep in mind that most species are relatively rare, in both fossil and modern ecosystems. You will find the same common species over and over, but many repeated visits to a site is necessary to have a hope of finding the rarer species and to get a fairly complete picture of the fauna or flora.

Generally, digging deeper into the rock will allow you to sample more rock and perhaps find some of the rarer species, or less weathered specimens of the common species. However, you have to consider on a case by case basis if the effort is worth it. In upstate New York there are places where you can find nice complete trilobites, but these are fragile and usually crumble if left to erode naturally from the rock, so digging/splitting rock is the best way to get pristine specimens. However, to make it worthwhile you need to know the most productive sites and layers to quarry. Some sites are well known (such as Penn Dixie in Hamburg NY); if you are prospecting on your own then layers that have lots of trilobite bits at the surface may be worth digging into. However, you should be aware that the most common outcome is sore muscles and a pile of broken rock without much to show for it. It's the occasions when you do find a great specimen that makes the chase addictive.

Don