For this activity you will need to watch the short video(s) for each fossil
.
You have been provided with key characteristics for each fossil in the fossil handout
. You will need to identify each fossil using your observations for each video and the information provided with them. You only need to indicate if the fossil is a brachiopod, bryozoan, cephalopod, trilobite, crinoid, mollusca, horn coral etc…Y You will need to create an excel table with the following columns in this order:
Sample Number and fossil name. You will be submitting this completed excel table
You will need to watch the short video(s) for each fossil. You will later have an assignment that will require you to identify each fossil using the Fossil Handout
.
Canvas Resource:
- Fossil Vide
Fossil Lab Handout
What is a fossil?
any remains, impression, or trace of a living thing such as a leaf, skeleton, or footprint, from a
plant or animal which lived in an older geologic period that you can see in rocks
What is an index fossil?
a widely distributed fossil, of narrow range in time, regarded as characteristic of a given
geological formation, used especially in determining the age of related formations.
http://dictionary.reference.com/browse/index+fossil
for a fossil to be an index fossil it has to: have had wide geographic distribution so that it can
be found in the rocks from many different regions and existed for a brief period so any rock
layer containing that fossil can be linked to a specific geologic time.
How are index fossils more useful than a non-index fossil?
Index fossils are useful for dating rock layers. If you know the time period when an organism
was alive, then any rock containing a fossil of that organism must have been deposited during
that same time period. Index fossils are also useful for correlating rock layers from widely
separated locations. For example if different rock layers from different regions contain the
same index fossil then the layers must have been deposited during the same time period (Fig.
1).
Figure 1. The rock columns are from different geographic regions. Fossils B and C are found in
several layers indicating they existed over a very long period of time, thus fossils B and C do
not meet the definition of an index fossil. Fossil D is found in only one layer but it is also in
only one column, thus it lacks wide geographic distribution and therefore does not meet the
requirements for being an index fossil. Fossil A is the best choice for being an index fossil. It
is found in only one layer i.e. it existed for a brief time and it is found in all four columns; it
has wide geographic distribution.
http://regentsearth.com/ILLUSTRATED%20GLOSSARY/IndexFossil.htm
What is an index location?
It is a region where index fossils are abundant. The Tri-state area, southwestern OH, northern
KY and southeastern IN is the index location for Upper Ordovician fossils.
How did this region become an index location?
During the Late Ordovician period (Fig. 2) the paleogeography of the Midwest region of the
US is believed to have been similar to Figs. 3 and 4. The landmass was located in the tropics
approximately 7 degrees south of the equator (Fig. 5) and was created by a mountain building
event, referred to as an orogeny, called the Taconic Orogeny. This event was the first of
several that were involved in the formation of the Appalachian Mountains. Crust to the west of
the subduction zone was being folded creating a series of basins (synclines) and arches
(anticlines) (Figs. 3 and 4). Basins were shallow filled with clear warm waters, ideal
conditions for the growth of reefs. Exoskeletons of the different organisms were preserved in
the shales and limestones of the region. The Upper Ordovician rocks of this region (Fig. 6) are
some of the most fossiliferous in the world, have excellent preservation, and have been studied
for over 175 years. More than 1,200 species within approximately 470 genera are present in
the rocks (Fig. 7). http://www.kspg.org/pdf/KSPG%20FT%2009%20Stop%201.pdf
Figure 2. Geologic time scale.
http://wps.pearsoncustom.com/pcp_80351_esm_tarbuck_earth_9/86/22073/5650798.cw/content/index. html
Figure 3. Shows the eastern portion of the United States during the Ordovician. Taken from Meyer and
Davis, 2009. A Sea Without Fish. IU Press, Bloomington.
Figure 4: Image showing the locations of the three main basins and arches that formed during
the Teconic Orogeny. Figure from presentation for Indiana Geologic Survey 2012 by P. David
Polly.
Figure 5. The proposed paleogeography of the Ordovician. Image from
http://jan.ucc.nau.edu/%7Ercb7/450_Ord_3globes.jpg
Figure 6. Stratigraphy in the region of the Upper Ordovician rocks.
http://strata.uga.edu/cincy/strata/cdpRichmond.html
Figure 7. Seas of the Ordovician. http://www.ucmp.berkeley.edu/ordovician/ordovician.php and
www.quoram.co.uk
Types of Fossils in the Upper Ordovician
Brachiopods
Brachiopods first appeared in marine environments in the early Cambrian and still exist today. A
modern brachiopod, Lingula, is believed to be related to a genera from the Ordovician.
Brachiopods were most abundant during the Paleozoic. They reef-builders, have bilaterally
symmetrical (each valve has a mirror-plane running through it) and feed on fine particles in the
water (Figs. 8 and 9). (www.asoldasthehill.org/Brachiopods.html)
Figure 8. Examples of some of the brachiopods found in this region. faculty.kfupm.edu.sa
a)
b)
www.ncfclub.org
members.wolfram.com
c)
d)
www.ncfclub.org
fossilidentification.weebly.com
e)
f)
louisvillefossils.blogspot.com
www.fallsoftheohio.org
Figure 9. Examples of Ordovician brachiopods.
Bryozoan
Bryozoans appeared in early Ordovician and all species colonize (Figs. 9 and 10). Like
brachiopods, they feed on fine particles in the water and have by-lateral symmetrical. In addition
these organisms tend to live between the low and high tide ranges. The hard parts are all that we
see today in the local rocks because they colonize together making a shell of calcium carbonate.
(fossilfactsandfinds.com)
Fenestrel/ina Sx
Fistulipora Ix
Fenestella Ix
Prismopora
lx
Archimedes sp.
Ix
Stomatopora 1 8x
Thamniscus 1 2x Penniretepora
4x
Diploporaria 1 2x Rhombopora 4x
Rhombopora Ix Stenopora Ix
Constellaria Ix
Figure 10. Examples of some of the bryozoans found in this region.
http://www.isgs.uiuc.edul?q=outreach/geology-resources/bryozoans
Leioclema 6x
Echinoderms
Modern day echinoderms include starfish, sea urchins, sand dollars, sea cucumbers and sea lilies
and are the largest phylum with no freshwater or terrestrial members. The most common fossil
echinoderm in this region is crinoids (Fig. 11 D) but a much sought after fossil is the edrioasteroid
(Fig. 11 C and Fig. 9f).
Figure 11. Sketches of different types of echinoderms.
http://museumvictoria.com.au/discoverycentre/infosheets/marine-fossils/echinoderms/
Crinoid
Crinoids consist of three parts; a stem that is used to stick to the sea floor, a body, and “arms” that
catch food from water flowing over the “arms” (Figs. 12 and 13). Crinoids are not common in the
seas today but during the Paleozoic they were, especially in shallow marine environments. During
the Permo-Triassic extinction they were nearly driven to extinction.
Figure 11. Schematic of the main parts of a crinoid. http://tolweb.org/Crinoidea
Figure 12. Picture of a crinoid stem. ww.ucmp.berkeley.edu
Horn coral
Horn corals are important world-wide reef builders, having a hard skeleton composed of calcium
carbonate. These organisms were abundant in the middle Ordovician to late Permian seas. They
are characterized as simple organisms because of their radial symmetry and lack developed organs
(Fig. 13). These fossils are easy to identify as they look like bugle snacks and have a wrinkled
appearance on the outer shell (Fig. 14)
Figure 13. Sketches of a horn coral. http://www.personal.kent.edu/~alisonjs/paleo/paleolab3cnidaria.htm and
http://www.ocean.odu.edu/~spars001/geology_112/laboratory/session_08/solutions.html
Figure 14. Image of a horn coral showing the “wrinkles” on the outer portion of the shell.
Molluska
Molluska the large phylum of invertebrate animals and the largest marine phylum. All mollusks
have a radula (toothy tongue), a mantle (thin layer of tissue covering organs and makes the shell)
and a muscular foot. There are three main groups in molluska; cephalopoda, gastropoda, and
bivalves (mulluska). Gastropods, cephalopods and bivalves appeared in the Cambrian. Each are
described below.
Cephalopod
For cephalopods the muscular foot is divided into tentacles. They first appeared in the late
Cambrian and reached their maximum diversity in the Ordovician. Cephalopods look like
segmented modern day squids (Fig. 15).
Figure 15. Image of an Ordovician cephalopod. galleryhip.com
Gastropods
Gastropods are the largest of the groups of molluska and includes, snails, conchs, abalones,
whelks, sea slugs, and garden slugs. All organisms in this group have one shell except for slugs
(http://mollusksscience.weebly.com). Gastropods first appeared in early Cambrian and were abundant
throughout the Paleozoic. The most common fossilized gastropods in this region are snails (Fig.
16).
Bivalves (Mollusks)
Bivalves have bilateral symmetrical (the top valve is a mirror of the bottom valve), feed on fine
particles in the water and live in marine environments Fig. 17. Modern looking bivalves first
appeared in the Ordovician.
Figure 16. Schematics of Ordovician gastropods.
http://faculty.kfupm.edu.sa/CHEM/thukair/paleontology/Phylum_Mollusca_(4).htm
Figure 17. Schematics of Ordovician molluscas.
http://faculty.kfupm.edu.sa/CHEM/thukair/paleontology/Phylum_Mollusca_(2).htm
Trilobites
Trilobites had a hard exterior shell composed of three body sections, thus the name trilobite, the
cephalon (head section), thorax (middle section) and the pygidium (tail section) (Figs. 18 and 19).
They were among the first organisms to have eyes and there was at least one type of trilobite from
the Cambrian till the end of the Paleozoic, with the greatest degree of diversity occurring in the
Cambrian. (fossil guy.com)
Figure 18. Schematic of a trilobite. http://www.kgs.ku.edu/Extension/fossils/trilobite.html
http://www.premdesign.com/flexi.jpg
Figure 19. Images of Ordovician trilobites.
http://www.uky.edu/OtherOrgs/KPS/images/flexigran1.jpg