Eye of a 400 million year old trilobite - Phacops speculator

Bruce Williams · Post by **Bruce Williams** » Thu Dec 14, 2006 10:00 am

Hi folks,

I’ve owned this fossil trilobite, Phacops speculator for years and although I’d previously looked at it with a 10X watchmaker’s loupe, I was very surprised at the level of detail that was revealed through the Meiji microscope.

This specimen was found in Morocco and is 45mm long with the eye measuring approximately 6mm in diameter.

Phacops lived in the middle Devonian period approximately 400 million years ago. The genus is noted for their unusual (schizochroal) compound eyes with their widely spaced, bulbous facets. The whole eye was mounted on a short stalk which enabled it to swivel rather like the eyes of a chameleon.

See this website for information on the lens structure of this trilobite’s eyes: http://www.trilobites.info/eyes.htm (the website also contains some amazing photos of a recently discovered trilobite with truly incredible eyes).

The first pic was obviously not taken through the microscope but has been included to provide context and scale for the other photo (stack of 11 images).

Bruce

Bill D · Post by **Bill D** » Thu Dec 14, 2006 2:51 pm

That is pretty cool. I guess each one of those bumps was a lens, making up a compound eye?

Bruce Williams · Post by **Bruce Williams** » Thu Dec 14, 2006 3:29 pm

Thanks for your comments Bill - yes each "bump" is a completely separate facet within the compound eye. Each lens having a separate cornea - that is they are not joined beneath the sclera.

Bruce

beetleman · Post by **beetleman** » Thu Dec 14, 2006 4:57 pm

Very cool photos Bruce and I love that link on trilobite eyes...very interesting

Kite · Post by **Kite** » Sat Dec 16, 2006 6:18 am

wow, lovely photos, and the site you linked to was very informative.

methinks I should read up on more trilobites

Ken Ramos · Post by **Ken Ramos** » Sat Dec 16, 2006 6:49 am

Quite an impressive set of photographs here Bruce. Looks as though you and the Meiji are getting along fine.

Wim van Egmond · Post by **Wim van Egmond** » Sun Dec 17, 2006 4:42 am

Yes, aren't they amazing. Especially those corrections for abberation! Unbelievable that they are extinct.

Wim

MacroLuv · Post by **MacroLuv** » Sun Dec 17, 2006 5:32 am

It's not too bad if they envolve.

Really, really old grandpa.

beetleman · Post by **beetleman** » Sun Dec 17, 2006 6:50 am

Just imagine what it would be like if that meteor had not wiped out 90% of all living things on the planet, I bet they would still be here. The horseshoe crab made it!!

Charles Krebs · Post by **Charles Krebs** » Mon Dec 18, 2006 8:46 am

Bruce... extremely interesting stuff here! Thanks for posting it... great to see something like this that one was not aware of, and then be able to read about it in detail. It's one of the reasons this place is so enjoyable.

Bruce Williams · Post by **Bruce Williams** » Mon Dec 18, 2006 12:04 pm

Thanks for all your supportive comments guys - Bruce