Preface
Welcome to a new format for fossils--the DMS "Fossil
Forum"! In our second installment,
we are connecting the fossil past with this year's DMS educational outreach program at our
own
clubhouse: The Greenbank Mill!
Today, we
will be exploring our state's Official State Fossil: Belemnites. Found around the
world as the remnants of ancient sea creatures, our local favorite is Belemnitella
americana.
Introduction
Welcome to our
second Fossil Forum!
This month, our
journey takes us into geologic time: the past. We are investigating a swimming
creature, whose fossil remains are easy to recognize: Belemnites. Enjoy!
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| Ancient Belemnoides |
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Modern day descendant: The
Cuttlefish
(Courtesy of Sarah Vandervlugt ©1998) |
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Ancient and squidlike, Belemnoides
(From j & h paleoscience
and OZ Fossils) |
Belemnites
are Coming!!
What exactly
are "belemnites"? Well, as you can see from the comparison pictures above,
they are
and were living sea creatures. As they maintained only one boney structure, the
"rostrum" (or "guard"),
it is the only candidate body part prone to fossilization. While alive, this boney
structure served as a
counterweight to the buoyancy of the creature.
As we see from the cigar-shaped objects at the
top of the page, these leftover bits would litter the
shallow paleosea bottom some 70 million years ago to later become diggable fossils.
They now call
the Mount Laurel Formation their home.
These squidlike Cephalopods combed the sea in
search of food for millions of years back in the
Cretaceous. Today, their descendants, such as the cuttlefish, do the same.
Their modern bone is
used for pet bird care, and in jewelry metal casting. I've done the latter with much
success.
As you can see, the belemnites were here, came
and went, then came back again as fossils for
us to talk about and collect. Though they traveled in large schools and were
prolific, they died out.
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| Belemnite & Guard
"bone" |
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Belemnite Model and Fossil
(Photo: Ken Casey from the Sophie Homsey Collection) |
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Belemnite Fossil
(Mike Viney, CSU) |
We speak of the cigar-shape
of the rostrum "bone", but notice the point at one end. Doesn't it look
aerodynamic, like the point of a rocket booster on the Space Shuttle. There is a
reason for nature's design here.
Yes, you guessed it! The fish swims backwards!
That's right. The finned area that houses the rostrum is
"aquadynamic". More like a boat hull, than a rocket ship, the belemnite's
fins and point act to push it through
the water. And, the tentacles around it's eyes
and head do the swimming, much like the octopus. They
possessed an ink sac and ten
tentacles, as well.
In addition to the biomechanical evidence that I've just
mentioned, today's cuttlefish swims in the same
manner--backwards!
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| Belemnite (artist's conception) |
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Belemnite's Cretaceous home
(Graphic from Earth History Resources) |
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Today's Cuttlefish swimming |
Now that we've seen what our
friendly sea creatures look like, we are ready to comb the world for fossils.
We'll
key in on our club's collecting area: Delaware.
Strewn in the fossil sands of time, namely the dredge spoils
of the Chesapeake & Delaware (C & D)
Canal--well,
almost. The simulated
fossil dig you see below is part of one of our club's educational programs
for the Girl
Scouts.
Member Sophie Homsey donated some of her belemnites and other marine fossils
for the
scouts to dig for and keep.
Thanks, Sophie!
From the pictures above, you
can get a general idea of the great fossils finds to be had when looking for
Belemnites. Though no opalized specimens have been known found in Delaware--who
knows, maybe an
opal-forming environment might be found here one day?
I know this is such a short primer
on the living and fossilized remains of our club state's official fossil,
though I hope it
whets your appetite to learn more from digging for yourself on site, and sifting through
the
links below.
Delaware State Fossil
DMS
C & D Canal Fieldtrip Page
Belemnoidea - Wikipedia, the free encyclopedia
In our Fossil Forum,
here is where DMS Members can add their fossil photos to share with us.
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Faceted Delaware Belemnite
(Work-in-Progress) |
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Finished Faceted Delaware
Belemnite
(Faceting and Photos courtesy of Tom Pankratz |
Who knew that our local Delaware Cretaceous Belemnites
could be faceted into a fine gemstone? Why,
DMS's own Tom Pankratz did! Tom is a long-time hobbyist faceter who
enjoys a unique challenge. When
picking up a rock, gem, or fossil, Tom thinks, 'Would this material facet
into a gemstone?'
During almost every show 'n tell, he poses the question
to we who are involved in the conversation, thus
piquing our interest. As a result of this particular exchange one club
meeting, Tom surprised us with some
photos of his work: a truly well-faceted Delaware fossil gemstone wonder.
Thanks, Tom!
Slideshow of Tom's faceting project: Delaware Belemnites
Until Next Time
We hope you have enjoyed our Belemnites
article. Please join us in the future
for more fossils in our new forum!
Until then, stay safe, and happy collecting. 
Article Contributors
Sophie Homsey, DMS Hospitality Chairperson (Fossils, Models & Knowledge)
Various DMS Members & Fossil Enthusiasts (in Photos)
The Delaware Geological Survey (facts)
I would like to gratefully acknowledge the generous
contributions of our fellow fossil
enthusiasts,
collectors, authors, curators, educators, professionals,
and club members who
made this work possible. Thanks.
R. Weller, Cochise College
American Broadcasting Company (ABC), British Broadcasting Company (BBC)
Sarah Vandervlugt
j & h paleoscience and OZ Fossils
Earth History Resources
Piper Films SA
Renaissance Photography/ The Somerville Collection, The Australian Museum
Ken Casey, DMS Webmaster (Photos)
Wikipedia.org
© 2006 All contributions to this article are covered under the
copyright protection of this article
and by separate and several copyright protection(s), and are to be used for the sole
purposes of
enjoying this scholarly article. They are used gratefully with express written
permission of the
authors, save for generally-accepted scholarly quotes, short in nature, deemed legal to
reference
with the appropriate citation and credit. Reproduction of this article must be
obtained by express
written permission of the author, Kenneth B. Casey, for his contributions, authoring,
photos, and
graphics. Use of all other credited materials requires permission of each
contributor separately.
Links and general contact information are included in the credits above,
and throughout this article.
The advice offered herein are only suggestions; it is the reader's charge to use the
information
contained herein responsibly. DMS is not responsible for misuse or
accidents caused from this
article. All opinions, theories, proofs, and views expressed within this article, and in
others on this
website, do not necessarily reflect the views of the Delaware Mineralogical Society.
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About the Author: Ken is current webmaster of the Delaware
Mineralogical Society. He has a diploma in
Jewelry Repair, Fabrication & Stonesetting from the Bowman Technical School,
Lancaster, PA, and worked as jeweler. He has
also studied geology at the University of Delaware. And,
he is currently a member of the Delaware Mineralogical Society and the Franklin-Ogdensburg
Mineralogical Society. E-mail: kencasey98@yahoo.com. |
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Belemnoidea (artist's conception)
