LAB 5. LATE PALEOZOIC LIFE

 ANIMAL AND PLANT LIFE OF THE LATE PALEOZOIC

The "age of marine invertebrates" continued through the Paleozoic and many of the marine animals that characterized the early Paleozoic continued into the late Paleozoic. Some other groups became more prominent or made their first appearance in the late Paleozoic; these include the corals, sponges, bryozoa, gastropods, crinoids and plants.

KINGDOM ANIMALIA

The Kingdom Animalia is defined as animals that are multicellular and use other organisms for food.

PHYLUM CNIDARIA

The most common, modern representatives of the Cnidaria are the corals, sea anemones, and the jellyfish.  Geologically, the corals are the most important coelenterates as they are well preserved and often provide the framework for major reef developments.  Corals are sessile benthonic, filter feeding, marine organisms and have well-defined radial symmetry.

Corals belong to the CLASS ANTHOZOA and are further subdivided to include the following orders:

order - Tabulate Coral:  These extinct corals were colonial and contained partitions inside their shells called tabulae (best seen in cross-section).  Radial septa are poorly developed or absent.  Each coral animal (polyp) lived atop a skeletal structure known as a corallite.

order - Rugose Coral:  These extinct corals were commonly solitary forms and are known as the horn corals.  Corals in this group have radial septa.

order - Scleractinian Coral:  These corals are known as the hexacorals (due to their six-fold septal symmetry) and are both solitary and colonial.  This group includes most of the modern corals.

1.      Three different species of late Paleozoic corals are on display in the lab:

            Caninia species (pennsylvanian)

            Favosites species (Devonian of New York)

            Lophophyllum profundum (Pennsylvanian)

Read about Rugose and Tabulate corals at the University of California at Berkeley Museum of Paleontology Coral page (http://www.ucmp.berkeley.edu/cnidaria/cnidariafr.html and then visit Yale’s Peabody Museum coral page (http://www.yale.edu/ypmip/) and the University of Newcastle Geology Department’s coral page: http://www-old.newcastle.edu.au/discipline/geology/research/posters.htm  click on  Images of Rugose and Tabulate Corals.

Use the images and descriptions to identify the corals in the lab. State whether each is a rugose or tabulate coral.

a.

b.

c.

2. Sketch the “living chamber” (calice) of Caninia; indicate the septa.

3. Make a sketch of Favosites.  Label the following parts:  tabula, corallite.

Note the lack of septa in Favosites.  Is this absence characteristic of tabulate corals, or did it most likely result from destruction of the septa by imperfect preservation?

PHYLUM PORIFERA

This phylum contains the sponges.  They are sessile benthonic organisms and most are marine.  Sponges are the simplest multicellular animals and have no true tissues or organs.  A sponge contains a central cavity surrounded by a body wall penetrated by a series of canals through which water passes.  A single "sponge" is usually a colony of simple sponge organs.  A framework of microscopic spicules composed of either calcium carbonate, silica, or organic material (spongin) supports the organism.

Sponges are not easily preserved due to the limited number of hard parts in their bodies.  The fossil record for sponges is not an abundant one, but it is of long duration as sponges have been in existence since the Precambrian.

Read about sponges at the University of California at Berkeley Museum of Paleontology (http://www.ucmp.berkeley.edu/porifera/porifera.html).

4. The Girtyocoelia (Pennsylvanian) specimens displayed in the lab are probably internal casts (the sponge filled with limey mud). What is the probable explanation for the small protrusions or pillars on the surface of these fossils?

5. Two different species of Paleozoic sponges are on display in the lab:

Girtyocoelia species (Pennsylvanian)

Astraeospongium meniscus (Silurian)

Visit the Oslo Museum of Natural History

http://www.toyen.uio.no/palmus/galleri/forsider/english/inverte.htm

and the Kansas geological Survey

http://www.kgs.ku.edu/Publications/ancient/f07_sponges.html

Use the images and descriptions to identify the lab specimens.

a.

b.

PHYLUM BRYOZOA

The Bryozoans include a large group of animals that grow in colonies and appear mosslike to the naked eye.  However, these very small animals have a complete digestive tract.  Their colonies are usually marine and sessile benthonic.  Each animal usually secretes its own small cup-shaped chitinous or calcarious shell (zooecium) that joins with others to form a twig shaped colony called a zoarium.  The zooecium appears as a raised bump with a tiny central cavity on the surface of the fossil.

Bryozoans became abundant in the Ordovician period and remained abundant for the duration of the Paleozoic era. Archimedes, a corkscrew-shaped bryozoan, is an index fossil for Mississippian strata.

6. Two different species of  Paleozoic bryozoa are on display in the lab:

            Hallopora species (Pennsylvanian)

            Archimedes species (Mississippian)

Visit the Oslo Museum of Natural History (http://www.toyen.uio.no/palmus/galleri/forsider/english/inverte.htm). Use the images and descriptions to identify the lab specimens.

a.

b.

7. Sketch Hallopora and indicate where the individual organisms lived.

Visit the University of Kentucky bryozoa page and answer the following question: (http://www.uky.edu/KGS/coal/webfossl/pages/bryos.htm)

8. Did the individual bryozoans live in the Archimedes fossils shown in the lab?

Yes      No  (Explain)

PHYLUM MOLLUSCA

CLASS GASTROPODA

The gastropoda (snails) are the most common and widespread of the mollusks.  Gastropods build a one piece, coiled shell, although some forms do not secrete a shell.

Since their first appearance in the Cambrian period, gastropods have adjusted to a variety of environments.  They are normally found in marine waters, but fresh water and terrestrial forms are also quite common.  Gastropod shells are coiled along an axis, resulting in a spiral shape and display no apparent plane of symmetry.  The shell of a gastropod is not divided into internal chambers, so that the organism may occupy the whole shell.

9. Three different species of  Paleozoic gastropods are on display in the lab:

            Trepospira species (Pennsylvanian)

            Solenicus regularis (Pennsylvanian)

            Worthenia tabulata (Pennsylvanian)

Visit the University of Kentucky gastropod page (http://www.uky.edu/KGS/coal/webfossl/pages/fossilkey/gastrotypes.html) and the Peabody Museum invertebrate paleontology page (http://www.yale.edu/ypmip/).

Use the images and descriptions to identify the lab specimens.

a.

b.

c.

PHYLUM ECHINODERMATA

The highly developed animals belonging to this phylum are known as the spiny-skinned animals.  They are benthonic marine organisms. Some forms are attached, some free moving.  They have an internal skeleton, and many echinoderms exhibit pentameral (five-fold) symmetry.  There are several classes of echinoderms.  The classes Echinoidea, Crinoidea, and Blastoidea have numerous fossil representatives.

CLASS CRINOIDEA

These animals were attached to the bottom by a radix (roots), and had a stem and crown, with arms extending from a calyx. The crinoid's common name is "sea lily."  Upon death, the long attachment stems break into smaller sections called columnals.  Crinoids first appeared in the Ordovician period, but they were so abundant in the Mississippian period that it has been called the "Age of Crinoids."

Observe the Pennsylvanian crinoid fossils displayed in the lab and then visit the University of California at Berkeley Museum of Paleontology crinoid page (http://www.ucmp.berkeley.edu/echinodermata/crinoidea.html).

10. Sketch a living crinoid attached to the sea floor; include the “roots” (attachment structures), the stem, the calyx and the feeding arms. Indicate on the sketch the part of the animal represented by the fossils in the lab.

KINGDOM PLANTAE

Plants are a group of nonmobile, multicellular organisms that are nearly all photosynthetic.  Although plants have been quite abundant throughout the geologic past, their preserved fossil record tends to be fragmentary due to poor preservation of land plants.  Plants are primarily found preserved through carbonization and imprinting.

The continental land masses had few plants before late Silurian and early Devonian time.  Thereafter an explosive radiation of land plants occurred.  The development of a VASCULAR SYSTEM, which transports water and nutrients to all cells within the plant, facilitated adaptation to a land environment (Note: in botany, “Division” is used in place of “Phylum”).

DIVISION LYCOPODOPHYTA

Club mosses, with simple vascular systems, and small leaves including scale trees. Some scale trees reached 30 meters in height.

                                    Lepidodendron - diagonal or diamond-shaped scars on "bark."

                                    Sigularia - vertical scars on "bark."

                                    Dominant in the Carboniferous period.

DIVISION EQUISETOPHYTA

            Horsetails, scouring rushes, including sphenopsids.

            Family Calamitaceae

            Calamities – parallel grooves on stem

11. Lepidodendron species and Calamities species are displayed in the lab. Visit the University of California at Berkeley Museum of Paleontology Lycophyta  page

http://www.ucmp.berkeley.edu/plants/lycophyta/lycophyta.html

 and Sphenophyta page

 http://www.ucmp.berkeley.edu/plants/sphenophyta/sphenophyta.html

Use the images and descriptions to identify the lab specimens.

a.

b.

12. To which class does fossil X (displayed in lab) belong?

CNIDARIA     PORIFERA     BRYOZOA

Why?