Wordsmith.org: the magic of words

Wordsmith Talk

About Us | What's New | Search | Site Map | Contact Us  

Previous Thread
Next Thread
Print Thread
#132508 - 09/02/04 01:23 AM Crystal Eyes  
Joined: May 2004
Posts: 89
amemeba Offline
journeyman
amemeba  Offline
journeyman

Joined: May 2004
Posts: 89

Trilobites could be said to be the first complex animals to evolve real eyes on our planet Earth.
Maybe.
We just don’t know.
Abruptly, in rocks that date back about 560,000,000 years, trilobite shells began to appear in ancient sea bottom muds and silts with no evidence as to how they had reached such an highly evolved state . By "highly evolved” I mean that trilobites appeared full-formed in the Cambrian fossil record wearing eyeglasses. Very cool eyeglasses too; wrap arounds, ghetto grannies, thick-lens nerdy types,...almost every species of trilobites had their own particular style of eyeglasses except the species of trilobites which were blind.

Calcite! The stuff of caves, great carved statues, ocean bottoms, the white chalk cliffs of Dover.
Calcite, a crystalized form of CaCO, calcium carbonate of which the more transparent form is Iceland Spar. The trilobites manufactured their light-collecting lenses from this inert compound to allow them to detect and react to the phenomena of light; a biological revolution.
In the book TRILOBITE: Eyewitness to Evolution Richard Fortey quotes Shakespeare’s The Tempest...

Full fathom five thy father lies;
Of his bones are coral made;
Those are pearls that were his eyes;
Nothing of him that doth fade,
But doth suffer a sea change
Into something rich and strange.


“If to voyage back to the time of the trilobite is a historical sea-change then there is nothing stranger than the calcareous eyes of the trilobite. And pearls are chemically the same as the trilobite unblinking lenses, being yet another manifestation of calcium carbonate, although peals are exquisite reflectors of light rather than transmitters of it. The weirdness of Shakespeare’s line results from his suggestions of pearly opacity, the hints of a corpse transformed; dead, yet seeing. The trilobite saw the submarine world with eyes tessellated into a mosaic of calcified lenses; unlike the dead seafarer, his stony eyes read the world through the medium of the living rock.”

****************************************************************

Pretty cool book.


#132509 - 09/02/04 02:32 AM Re: Crystal Eyes  
Joined: Oct 2000
Posts: 5,400
of troy Offline
Carpal Tunnel
of troy  Offline
Carpal Tunnel

Joined: Oct 2000
Posts: 5,400
rego park
horse shoe crabs, --wonderful other worldly creatures that they are, also have lens(and eyes) from from hard clear parts of of their shell..

they have no openings in the top part of their shell for the lenses, they 'light sensing' cells of their very primitive eyes (they have compound eyes) just nestle up against the clearish/translucent parts of the upper shell.

(you're inland, right? i don't know how far south horse shoe crabs are found--even if you were on the coast. they are still common in sheltered areas here in NY area. LI sound, well the bays and wet lands on Long island and CT, RI, and MA still harbor a large population.)


#132510 - 09/02/04 03:32 AM Re: Crystal Eyes  
Joined: May 2004
Posts: 89
amemeba Offline
journeyman
amemeba  Offline
journeyman

Joined: May 2004
Posts: 89
Wonderful, Of Troy, do you happen to know if the horseshoe crab's light-gathering lenses are crystilized in the same manner as the trilobites,i.e. with a tri-axial alignments which helps the sensor cells determine the direction of the incoming light? Interestingly, the horseshoe crab is considered a modern relative of trilobites. Not a direct descendent but maybe a second cousin back in the good old days of the Ordovician, back before the big kill off at the end of the Paleozoic. According to Richard Fortey, female trilobites probably had their egg sacs in their heads as do the horseshoe crabs of today. Richard reports that he was served Limulus eggs (the only eatable part of the horseshoe crab) in Thailand. He said that inside the head section of the crab were big yolky eggs. The horseshoe crab eggs tasted rancid and intense. He thought that his beloved trilobite's eggs would have tasted sweeter,



Moderated by  Jackie 

Forum Statistics
Forums16
Topics13,879
Posts224,120
Members9,031
Most Online3,341
Dec 9th, 2011
Newest Members
brork, santo, piostylist, prgill, thefoeller
9031 Registered Users
Who's Online Now
1 registered members (1 invisible), 44 guests, and 2 spiders.
Key: Admin, Global Mod, Mod
Top Posters(30 Days)
Top Posters(All Time)
wwh 13,858
Faldage 13,803
Jackie 11,613
tsuwm 10,538
LukeJavan8 9,038
AnnaStrophic 6,511
Wordwind 6,296
of troy 5,400
Disclaimer: Wordsmith.org is not responsible for views expressed on this site. Use of this forum is at your own risk and liability - you agree to hold Wordsmith.org and its associates harmless as a condition of using it.

Home | Today's Word | Yesterday's Word | Subscribe | FAQ | Archives | Search | Feedback
Wordsmith Talk | Wordsmith Chat

© 1994-2017 Wordsmith

Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.014s Queries: 13 (0.003s) Memory: 2.6607 MB (Peak: 2.7416 MB) Zlib disabled. Server Time: 2017-11-20 23:10:49 UTC