1. BAESIBAESI November 12, 2011: THE FOSSIL RECORD: Fossil Guide Instructor:  Jonathan Hendricks  Assistant Professor of Paleontology, SJSU, Dept. Geology  Email: jonathan.hendricks@sjsu.edujonathan.hendricks@sjsu.edu November 12, 2011: THE FOSSIL RECORD: Fossil Guide Instructor:  Jonathan Hendricks  Assistant Professor of Paleontology, SJSU, Dept. Geology  Email: jonathan.hendricks@sjsu.edujonathan.hendricks@sjsu.edu

2. Slide shows pictures of stromatolites. Oldest Fossils: Stromatolites Oldest known fossil group: ~3.5 billion years old, Australia Stromatolites: mat-like structures formed mostly by photosynthesizing bacteria called cyanobacteria.  Slimy layers + sediment.  Oxygen by-product of photosynthesis.  Fossil Record: Archean (become more abundant and diverse in Proterozoic) to Today  Mostly found today where grazing animals like snails cannot eat them. By: “Rygel” (Creative Commons)

3. Fusulinids  Single-celled.  Fossil Record: Pennsylvanian to end- Permian.  Primary guide fossil for late Paleozoic.  Some very large (1-10 cm).  Make up the bulk of some late Paleozoic rocks.  Single-celled.  Fossil Record: Pennsylvanian to end- Permian.  Primary guide fossil for late Paleozoic.  Some very large (1-10 cm).  Make up the bulk of some late Paleozoic rocks. Slide shows a photograph and drawing of fusulinids (images from the Kansas Geological Survey). "The source of this material is the Kansas Geological Survey website at http://www.kgs.ku.edu/. All Rights Reserved."

4. Corals Corals belong in the Phylum Cnidaria, along with jellyfish and sea anemones. Three major groups:  Tabulate corals: Paleozoic  Rugose corals: Paleozoic  Scleractinian corals: Mesozoic and Cenozoic Corals belong in the Phylum Cnidaria, along with jellyfish and sea anemones. Three major groups:  Tabulate corals: Paleozoic  Rugose corals: Paleozoic  Scleractinian corals: Mesozoic and Cenozoic

5. Tabulate Corals  Skeleton calcitic.  Exclusively colonial.  Tightly packed, tubular coralites (chambers of individual coral polyp); horizontal dividers along length of tube (tabulae).  Septa absent or short.  Early Ordovician to Permian (Paleozoic).  280 genera.  Important Silurian and Devonian reef-makers.  Skeleton calcitic.  Exclusively colonial.  Tightly packed, tubular coralites (chambers of individual coral polyp); horizontal dividers along length of tube (tabulae).  Septa absent or short.  Early Ordovician to Permian (Paleozoic).  280 genera.  Important Silurian and Devonian reef-makers. Slide shows a photograph of a tabulate corals.

6. Rugose Corals  “Horn Corals”  Skeleton calcitic.  Some solitary, some colonial.  Middle Ordovician to Permian (Paleozoic).  Most diverse (800 genera) and abundant Paleozoic corals.  “Horn Corals”  Skeleton calcitic.  Some solitary, some colonial.  Middle Ordovician to Permian (Paleozoic).  Most diverse (800 genera) and abundant Paleozoic corals. Slide shows two photos of horn coral fossils.

7. The Work of John Wells  Devonian rugose corals.  Show two types of growth layers: thick and thin.  Thick: annual/seasonal.  Thin: day/night cycles.  Wells counted number of thin (daily) bands between thick (annual) bands.  Devonian corals: 400.  Pennsylvanian: 387.  What does this mean?  Devonian rugose corals.  Show two types of growth layers: thick and thin.  Thick: annual/seasonal.  Thin: day/night cycles.  Wells counted number of thin (daily) bands between thick (annual) bands.  Devonian corals: 400.  Pennsylvanian: 387.  What does this mean? Slide shows a picture of a rugose coral fossil with many growth lines.

8. Scleractinian Corals  Skeleton aragonitic in modern corals.  Some solitary, some colonial.  Six primary septa (divisions) within coralites.  Middle Triassic to Recent. (Where are the Early Triassic corals??).  600 genera.  Wide variety of forms.  Major producers of reefs since the Triassic.  Skeleton aragonitic in modern corals.  Some solitary, some colonial.  Six primary septa (divisions) within coralites.  Middle Triassic to Recent. (Where are the Early Triassic corals??).  600 genera.  Wide variety of forms.  Major producers of reefs since the Triassic. Slide shows a “close-up” view of a hexacoral. By: Jan Derk (Wikimedia Commons)

9. Brachiopods  “Lamp shells”  Two calcitic (typically) valves.  Marine; sessile, intertidal to abyssal.  Filter feeders (using lophophore).  Paleozoic: great diversity and abundance.  Today: cryptic and 120 genera.  “Lamp shells”  Two calcitic (typically) valves.  Marine; sessile, intertidal to abyssal.  Filter feeders (using lophophore).  Paleozoic: great diversity and abundance.  Today: cryptic and 120 genera. Slide shows a photograph of a brachiopod shell.

10. Mollusks  Second most diverse phylum (after arthropods): ~93,000 extant species. 70,000 fossil species.  Three major groups, all of which are known from the Paleozoic, Mesozoic, and Cenozoic eras:  Bivalves  Gastropods  Cephalopods  Second most diverse phylum (after arthropods): ~93,000 extant species. 70,000 fossil species.  Three major groups, all of which are known from the Paleozoic, Mesozoic, and Cenozoic eras:  Bivalves  Gastropods  Cephalopods Slide shows a drawing of a gastropod shell by Ernst Haeckel. By Ernst Haeckel.

11. Bivalves  Bivalvia = Pelecypoda  Clams, oysters, cockles, scallops, and mussels.  Cambrian to Recent.  15,000 extant species, 40,000+ fossil species.  Two valves (CaCO 3 ).  No head, few sense organs.  Foot used for burrowing.  Gills modified for respiration and filter feeding.  Mostly sessile, aquatic filter feeders.  Bivalvia = Pelecypoda  Clams, oysters, cockles, scallops, and mussels.  Cambrian to Recent.  15,000 extant species, 40,000+ fossil species.  Two valves (CaCO 3 ).  No head, few sense organs.  Foot used for burrowing.  Gills modified for respiration and filter feeding.  Mostly sessile, aquatic filter feeders. Slides shows an illustration (by Ernst Haeckel) of a variety of bivalve shells. By Ernst Haeckel.

12. Gastropods (Snails and Slugs)  Most diverse mollusk group (~100,000 species).  Cambrian to Recent.  Members occupy many different habitats: marine (benthic and pelagic), freshwater, and terrestrial.  Most diverse mollusk group (~100,000 species).  Cambrian to Recent.  Members occupy many different habitats: marine (benthic and pelagic), freshwater, and terrestrial. Slide shows an illustration of gastropod shells by Ernst Haeckel. By Ernst Haeckel.

13. Cephalopods  650 extant species; 17,000 extinct species.  Late Cambrian to Recent.  Subclasses: Coleoids (squids, octopi, and cuttlefish), nautiloids, endoceratoids, and ammonoids.  650 extant species; 17,000 extinct species.  Late Cambrian to Recent.  Subclasses: Coleoids (squids, octopi, and cuttlefish), nautiloids, endoceratoids, and ammonoids. Slide shows an illustration by Ernst Haeckel of various extant cephalopods and a photograph of a model of a modern nautilus.

14. Ammonoids  “Serpent Stones”  “Horns of Ammon”  “Serpent Stones”  “Horns of Ammon” Slide shows various illustrations of ammonoids drawn by Ernst Haeckel. By Ernst Haeckel.

15. Echinoderms  “Spiny skin”.  Five-fold symmetry.  Cambrian to Recent.  Weird.  All marine.  Typically gregarious.  Two subgroups with great fossil records:  Crinoids  Echinoids  “Spiny skin”.  Five-fold symmetry.  Cambrian to Recent.  Weird.  All marine.  Typically gregarious.  Two subgroups with great fossil records:  Crinoids  Echinoids Slide shows photograph of a starfish. JRH.

16. Crinoids  “Sea lilies”  Most of diversity extinct (~700 extant species; 6000 extinct species).  Ordovician to Recent.  “Starfish on a stick”: arms, calyx, stem, root.  Filter feeders; tube feet on arms move food to mouth.  Stem segments have produced “crinoidal limestones”.  “Sea lilies”  Most of diversity extinct (~700 extant species; 6000 extinct species).  Ordovician to Recent.  “Starfish on a stick”: arms, calyx, stem, root.  Filter feeders; tube feet on arms move food to mouth.  Stem segments have produced “crinoidal limestones”. Slide shows an illustration of various crinoids by Ernst Haeckel. By Ernst Haeckel.

17. Echinoids  Echinoids; Sea urchins and sand dollars.  Late Ordovician to Recent.  Very good fossil record (hard calcitic test; burrowing creatures).  Spines.  Mostly herbivorous (eat algae).  Echinoids; Sea urchins and sand dollars.  Late Ordovician to Recent.  Very good fossil record (hard calcitic test; burrowing creatures).  Spines.  Mostly herbivorous (eat algae). Slide shows a photographs of a fossil echinoid.

18. Trilobites  Arthropod phylum (bug-like animals).  Cambrian (maximum diversity) to Permian (Paleozoic).  About 1200 genera.  Most important fossils for dating Cambrian rocks.  Exoskeleton: mostly calcite; had to molt to grow.  Cephalon (=head; facial sutures), thorax, pygidium (=tail); thoraxes show trilobation.  Arthropod phylum (bug-like animals).  Cambrian (maximum diversity) to Permian (Paleozoic).  About 1200 genera.  Most important fossils for dating Cambrian rocks.  Exoskeleton: mostly calcite; had to molt to grow.  Cephalon (=head; facial sutures), thorax, pygidium (=tail); thoraxes show trilobation. Slide shows an illustration of trilobites by Ernst Haeckel and a photograph of two trilobite fossils. By Ernst Haeckel.

19. Vertebrates  Animals with bones.  Cambrian: first vertebrates.  Devonian: first tetrapods (four-limbed vertebrates).  Triassic: first mammals.  Cretaceous: first placental mammals.  Paleogene: first modern mammal groups.  Pleistocene: first humans.  Animals with bones.  Cambrian: first vertebrates.  Devonian: first tetrapods (four-limbed vertebrates).  Triassic: first mammals.  Cretaceous: first placental mammals.  Paleogene: first modern mammal groups.  Pleistocene: first humans. Slide shows a photograph of a fossil ground sloth skeleton.