Download Consider the Lowly Trilobite: God`s thumb print in the Cambrian

Consider the Lowly Trilobite:
God’s thumb print in the Cambrian
Dan Callahan
November 2012
Copyright Statement
• The photographs contained herein are used as under the Fair Use portion of the US Copyright Law Section 107 and its revisions (1961 Report of the Register of Copyrights on the General Revision of the U.S. Copyright Law). They are used herein for teaching and education and are not used for any profit making endeavors. They may not/shall not be used for a for‐profit endeavor and all rights are retained by the original owners of the photographs. For details, please consult http://www.copyright.gov/fls/fl102.html. FASCINATING FACTS ABOUT TRILOBITES:
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Trilobites are extinct arthropods… [thought to be] distant relatives of modern lobsters, horseshoe crabs and spiders.
They lived primarily in [what is called] the Lower Cambrian Period Trilobites are named not for their head (cephalon), thorax and pygidium, but rather for the three axial lobes that divide their body length‐wise.
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Their fossilized remains have been found on every continent on earth.
Trilobites ranged in size from 1cm to over 70 cm. (about 27 inches!)
There are over 20,000 scientifically recognized trilobite species.
There are 10 “Orders” of trilobites, under which the more than 20,000 recognized species are organized.
In life, trilobites were covered by a thick chitinous exoskeleton which was molted as they grew.
FASCINATING FACTS ABOUT TRILOBITES:
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Many trilobite fossils represent remnants of their shed exoskeletons, rather than of the trilobites themselves.
Some trilobite species have been found with long spines projecting from their shell… believed to have served as protection from predators.
Trilobites were probably the first life forms with complex eyes, with some species having hundreds of individual lenses per eye.
Some trilobites could enroll for protection.
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Some trilobite fossils show evidence of soft appendages used for feeding and locomotion.
Famous “soft‐bodied” trilobite localities include The Burgess Shale in British Columbia, The Emu Bay Shale in South Australia and The Chengjaing Formation in China.
Some trilobite fossils show signs of predation.
Collecting trilobites has a long history… some have been found in human burial mounds dating back more than 50,000 years.
Why is This So Interesting?
• They are from the Cambrian Strata, said by the evolutionist to be the oldest layer of strata
• Their eye lens is transparent calcium carbonate
• “Trilobites have solved a very elegant physical problem and apparently know about Fermat’s principle, Abbe’s sine law, Snell’s laws of refraction and the optics of birefringent (i.e., double refraction) crystals”
– Clarkson and Levi‐Setti, “Trilobite Eyes and the Optics of Des Cartes and Huygens”, Nature: 254, 4/25/74, p 6663 ff
Hmmm….interesting…
• “These lenses optimize both light collecting and image formation better than any lens… that optical physics has ever been able to formulate.” – N. Eldredge, “A Trilobite Panorama in Eastern North America” Fossils Magazine: 1, 1976, P. 58‐67
• “The design of the trilobite’s eye lens could well qualify for a patent disclosure”
– F. Levi‐Setti, Trilobites: A Photographic Atlas
(2nd Edition), 1993, p. 58
Notable Trilobite Beds
ALGERIA
Trilobite Hunting anyone??
Fossils versus alive!
Trilobite Eyeshades?
Morocco
• Growing slowly at first, fossil and mineral exports expanded so rapidly beginning in the late 1980’s and early 1990’s that today more than 50,000 Moroccans earn their livelihoods in the fossil and mineral specimen mining and export business. Collecting, especially among youngsters, has gone worldwide, and the us market is the largest.
Up Close
Fig. 1. Fossil remains of the Upper Ordovician (Bohemia), phacopid,
schizochroal‐eyed trilobite, Dalmanitina socialis. (A) Head of specimen
preserved as an internal mould (original exoskeleton dissolved),
showing position of eyes (light photomicrograph). (B) Left eye of
same, showing lenses preserved as internal moulds (photomicrograph).
(C) Latex replica of the lenses of same, showing the under‐surface of the upper lens unit, with central nipple (SEM photograph).
The Challenge, Stated Clearly
• As Darwin noted in the Origin of Species, the abrupt emergence of arthropods in the fossil record during the Cambrian presents a problem for evolutionary biology. There are no obvious simpler or intermediate forms—either living or in the fossil record—that show convincingly how modern arthropods evolved from worm‐like ancestors. Consequently there has been a wealth of speculation and contention about relationships between the arthropod lineages.
~ Frank Sherwin, M.A., Institute for Creation Research
SEE ALSO: Osorio, D, J. P. Bacon, and P. Whittington. 1997. The evolution of arthropod nervous system. American Scientist 95: 244.
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Abstract:
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The compound eyes of trilobites provide the best examples of fossilized sensory organs for which the function in life can be worked out today because the optical array of their corneal lenses preserves the geometry with which the eye originally sampled the visual world. An analysis of trilobite vision is strengthened by the use of new mathematical approaches to compound eye design. In particular, the product of the facet diameter (D) and the interommatidial angle (Δφ) gives the value of the eye parameter, DΔφ, which is a reliable indicator of the photic conditions in which the eye was used. In modern arthropods, DΔφ
values range from 0.3 for animals active in bright sunlight to 20 or more for nocturnal or deep‐sea animals. Two major types of compound eyes existed in trilobites: schizochroal and holochroal. In our previous work with schizochroal eyes in the phacopids Phacops rana
crassituberculata and Phacops rana milleri, we found that eye parameter values ranged from 10 to >150. These values of the eye parameter are much greater than in any living arthropod, implying that modern compound eye theory does not apply to schizochroal eyes. We suggested that each ommatidium of the schizochroal eye served as a miniature lens eye. If so, phacopid vision must have been unique, with multiply overlapping visual fields. In the new work of this paper, we examined holochroal compound eyes in Asaphus cornutus, Isotelus gigas, and Homotelus sp. Holochroal eyes contain far more ommatidia than do schizochroal types, reducing both facet diameter (D) and interommatidial angle (Δφ). Thus, DΔφ values in these species fall into the same range as in modern nocturnal compound eyes. This implies that function of the holochroal eye was similar to that of modern arthropods, and that they were used in moderate to dim intensities of light.
Genesis Chapter 1
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20 And God said, Let the waters swarm with swarms of living creatures, and let birds fly above the earth in the open firmament of heaven.
• 21 And God created the great sea‐monsters, and every living creature that moveth, wherewith the waters swarmed, after their kind, and every winged bird after its kind: and God saw that it was good.
• 22 And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let birds multiply on the earth.
• 23 And there was evening and there was morning, a fifth day.