COLLECTING OF FOSSIL TETRAPODs, the land VERTEBRATES
In regions which have been subjected to little exploration by collectors or in areas which are continually ravaged by natural erosion factors such as in badlands or on seashores, fossil remains of tetrapod vertebrates, including amphibians, reptiles and mammals, are not uncommon, though they are usually fragmentary.
The avocational fossil collector (aka "amateur"...I know, a bad word!) or student can be content to collect isolated bones or teeth of tetrapods, leaving (and leading) professionals to the complete skeletons which require many years of experience to properly collect. Over time, nature has a way of reducing important skeletons to dust, but in between the moment a skeleton is weathered out of the strata and exposed, and the time it is washed away into oblivion, lots of cool parts can be found and collected. Fossil bones, no matter how hard and well preserved, have been subjected to continual earth and soil shifting and are often broken into hundreds of pieces, held together in a seemingly stable skeleton only by the surrounding matrix. And remember that gravity is at work on all fossils. If you find scraps of bone at the bottom of a hill, guess where the skeleton is eroding from.
A larger fossil skeleton may requires days or weeks of work to collect and often, a novice collector only begins to realize this after a single day's attempt. At that point, he becomes frustrated and begins pulling bones from the strata, and alas, ends up with a pile of useless fragments, of little value to paleontology. The vertebrate fossils in a lot of private collections are crumbs, bits and pieces of a much more complete fossil. I can't stress how important it is to learn proper collecting techniques for intact land vertebrate fossils. There are a lot of rewards for patience.
Unlike Paleozoic invertebrate fossils, bones recovered from the Cenozoic marls are not petrified, and are much more likely to break during excavation and transportation. Again, I must advise the collector to seek professional assistance if he or she believes that a find is of some major importance, but as is sometimes and unfortunately the case, a collector cannot find a paleontologist, or simply cannot drag a busy scientist from his office with any enticement. For this reason, I will outline the following procedure for collecting vertebrate fossils. But always try to get professional help or guidance as this can make the difference between making a discovery into a major scientific contribution or having a few crumbs of bone which usually get discarded eventually.
Use of a plaster jacket
can be a critical part of the entire vertebrate fossil collecting operation, for if the specimen has been packed loosely within the plaster jacket or if the jacket does not have a firm hold of undercuts under the block, the specimen can easily end up as shale and fossil hash filling the hole.
Always cut far enough under a specimen so that it is pedestaled or toadstool if possible. The block is then broken from its pedestal and hopefully it can be turned without all of the material within spilling out, which has made grown men cry. The jacket is then continued around the newly exposed side of the block, and it is ready for transport.
The preceding is a gross over-simplification of a very complicated and risky procedure. I strongly suggest that every serious fossil hunter gets a copy of Handbook of Paleontological Techniques, edited by Kummel and Raup (W. H. Freeman and Company), and carefully studies the section entitled Tetrapods, which includes a detailed description of plaster jacketing techniques.