A pretty darn good bad cast

There. I have said it. This may be the only time I say it, so I will say it again. This is actually a pretty darn good bad cast. Two casts actually.

Can I say it? Go on. A rather beautiful cast of the top and bottom of a trilobite.

Can I say it? Go on… A rather beautiful cast of the top and underneath of a trilobite.

Apart from a few scuffs where the paint has rubbed off, and a little pink crayon where someone has used this for some children activity as a fossil rubbing, they are actually quite beautiful. (Please don’t use accessioned museum specimens for crayon rubbings. You can buy cheapish casts from fossil suppliers, then place a piece of paper over it and rub a crayon on top. It comes out with a lovely rubbing of the fossil.)

The previous bad casts have been awful. Shocking. So terrible that I have had to really look into what they are supposed to represent. But these are good. Really good in comparison!

What has me even more excited is that there is information written on the back! Can you imagine! A bad cast with information!

Striking gold! Information about a specimen with a specimen! A true rarity in itself!

Striking gold! Information about a specimen with a specimen! A true rarity in itself!

The information tells us what the fossil was, where it was found and who made it. It is a cast of a trilobite, which were pretty successful marine creatures living from around 520 million years ago until the whole group became extinct around 250 million years ago. From species smaller than a finer nail to the big Welsh beasts that would have terrified us paddling in the shallows, trilobites were amazing creatures. Some could roll up into balls for protection, like a woodlouse might today. Others had exquisite spines and spikes growing out of their hard external skeletons.

This cast is of the beautiful trilobite Triarthrus eatoni which lived around 440 million years ago (the Upper Ordovician Period). These casts are actually casts of models of this trilobite. But why the models themselves were made is wonderful is all part of their story.

The Ordovician sediments at a small site in Rome, New York, preserved trilobites and other creatures in unbelievable detail. They were discovered in 1892, and came to the attention of Mr Charles Beecher who was working at Yale University. Beecher noticed that almost everything of this trilobite was preserved, the antennae, and even the gills on the legs.

Gorgeous, almost perfect, pyrite fossils of the little trilobite.

Gorgeous, almost perfect, pyrite fossils of the little trilobite. Image from here.

The specimens themselves were about as long as my thumb. To truly show them off, Beecher made larger brass models with this new understanding of trilobite anatomy. The models are not exactly the same as the fossils, but Beecher appears to have been given a little artistic licence.

These casts are of Beechers models. They show a lot of detail of these extinct creatures. Long antennae coming out from under the head can be seen. These would have been used to sense movement and chemicals in the water. Feathery gills attached to each leg let us see how trilobites were able to breathe under the water. Such soft tissue preservation is very rare in the fossil record, because it decays so quickly.

This will be the only time we get excited about a rather good bad cast. There are a few shockers to come. Lets enjoy this one.

Advertisements

1 Comment

Filed under Museum Collections

One response to “A pretty darn good bad cast

  1. Pingback: The croc in the rock | FromShanklin

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s