trilobite

This edition of the photo of the week highlights another piece from my personal collection.

This is a cephalopod. More specifically it is a member of the Order Endocerida and the Family Endoceratidae. This creature, which hopefully you can see was pretty large (golf tee for scale) was the largest of the Ordovician cephalopods found in Ontario and this is a particularly fine/large example mainly because it tapers all the way to the apex at the end, which is a very rare find, and because of its large size (~7ocm). Cepahlopods, such as Endoceras, were the top predators of the Ordovician ocean that once covered most of southern Ontario and they grew up to several metres long. The cephalopods of the past resembled modern squids of today. Indeed, they were the progenitors of the Cretaceous ammonites and the squid and octopi of today’s oceans. If you enjoy calamari, thank a cephalopod!

This zoomed in look at the cephalopod shows the siphuncle and the suture lines, which divide the inner chambers. The siphuncle was an inner tube that ran the length of the cephalopod and allowed it to control its buoyancy. The fact that the siphucle and sutures are clearly preserved is a great feature of this cephalopod, however, there is more….

When I was extracting this fellow from the giant boulder he was in I was unfortunate enough to break him in several pieces, which I have now super-glued together. But why, you may ask, did I not super-glue him completely together? The answer is pictured below.

One of the points at which he broke contained this tiny little trilobite, which I am pretty sure is a Bumastus, based on the shape of its pygidium (tail). I decided not to rejoin the parts together so that we could still see this little dude that made this find a 2 for 1 deal. The obvious question is what is this little guy doing in a cephalopod? Was he eaten? Was he seeking shelter? Was he eating the already dead cephalopod? I have no idea, and it is pretty hard to prove one way or the other now. Please weigh in and let me know how you think he got in there!

Also, the other great fossil in my collection, the two trilobites that were featured in the Photo of the Week #25 and are named “Bert and Ernie”. We have a similar pair here, but they lack the awesome name. Please suggest your favourite names for this odd couple.

Cheers,

Matt