A GUIDE TO DINOSAUR EGGS

Dinosaur eggs are fascinating and important fossils which allow us insights into the reproductive biology and behaviour of dinosaurs. Whole eggs are rare and clutches of eggs rarer still, however dinosaur eggshells are relitively common finds in many parts of the world. Dinosaur eggs come in many sizes and they can range in shape from sherical to elongated. Dinosaur eggs can be found all over the world, however a large proportion are found in Asia and the vast majority date to the Late Cretaceous Period.

The only reliable way for palaeontologists to tie a certain kind of egg to a particular dinosaur is to find embryonic remains. This does happen, but is exceedingly rare. Even in those cases where palaeontologists are lucky enought to find an unhatched egg, the egg has to have been fertilised in order to stand a chance of holding embryonic remains. Furthermore, those embryonic remains need to have survived the processes of fossilisation, which they very often do not, as is demonstrated by the diagram below (From Mueller-Towe et al. (2002)).

If you're new to dinosaur eggs, it is highly recommended that you start out collecting eggshells rather than whole eggs. Eggshells are easily purchased, often for pocket money prices, and they will allow you to familurise yourself with the various types of ornamentation present on dinosaur eggshells. Sadly, when it comes to whole eggs, there are many examples of forgeries out there and understanding the surface texture of different types of eggs is one of the key ways to avoid getting burned.

Here are some common types of eggshell from around the world:

Unfortunately, dinosaur eggs are some of the most common types of fake fossil we come across.  Many of these eggs are offered for sale by dealers from China and Malaysia on auction websites.

Luckily for us, once you've encountered a few, many of these fakes are easily spotted and avoided. There are of course exceptions, but we'll get to those too. So without further ado, lets see what those naughty little thieves have for us ...

I'm not even sure whether to call these fake, as some of the people selling them may honestly believe they're dinosaur eggs, but they're definitely not. At any given time there seems to be a couple of these listed on auctions sites, sometimes with eye watering price tags. None of them show any signs of being an egg, other than being slightly round, and are simply natural concretions.

Again, at any given time there's a few of these being offered on auction sites, and they're probably one of the most obvious fakes you'll come across. As you'll know from what we discussed above, the surface of this "egg" in no way resembles that of a real dinosaur egg. I've never held one of these, so I won't guess at what they're made of, but they are complete fabrications.

If I were to hazard a guess at the kind of fake eggs collectors get caught out by the most, it would be these. These fabricated eggs are mainly offered by Asian dealers and they're generally offered for a few hundred pounds/dollars. They're always nice and round and lack any surface texture. In fact, the surface of these eggs are often coated in a thin layer of matrix, so as to give the appearance that the eggshell ornamentation is being obscured by dirt.

This one was posted by a member on The Fossil Forum to warn fellow collectors and it's one of the best forgeries I've seen. While a close look at the "eggshell" reveals it's fabriacted, the cracked shells and imperfect shape make it a very convincing fake. This is an excellent example of why it pays to familiarise yourself with dinosaur eggshell ornamentation.