1. Marine Invertebrate Paleo
Kingdom Protista
Single Celled Eukaryotes

2. Primary Producers/Autotrophs
Coccolithophores
Kingdom: Protista
Division: Chrysophyta (golden-brown algae)
Class: Coccolithophyceae
Unicellular, photosynthetic biflagella-bearing organisms
Produce calcareous skeletal plates called coccoliths
Mineralogy calcite

3. Test called the coccosphere < 200 m depth, need sunlight
Nannoplankton (5-60 mm in size)
< 200 m depth, need sunlight
Geologic range: Common early Jurassic to Present
K/T event greatly affected their diversity (4-5 spp. survive)
Good biostratigraphic indicators
Use a third appendage called the haptonema to attach to a substrate.

4. Reproduction Ecology Asexual Tropics to temperate open-ocean
Longitudinal fission of the cell
Multiple fission of the cell
Ecology
Tropics to temperate open-ocean
Geographic distribution controlled by:
Light
Salinity
Water temperature
Circulation patterns

5. Photoautotrophs continued
Diatoms
Kingdom Protista
Division: Chrysophyta
Class: Bacillariophyceae
Geologic Range: Jurassic to Recent
Bivalved test called Frustules
Epitheca
Hypotheca
Mineralogy Opal-A (SiO2-nH2O)

6. Two Morphological Groups
Centrales (centric) “circular”
Generally planktonic
Pennales (elongate) “football” shaped
Generally benthic
Occur in all environments
Freshwater
Marine
Terrestrial/soils
Air

7. Reproduction Ecology Diatomites Asexual Photic zone <200 m
Simple binary fission (always new hypotheca)
Followed by sexual spore formation
Ecology
Photic zone <200 m
Diatom blooms 106 cells/Liter
Normal cells/Liter
Diatomites
Deposits composed of frustules
Upwelling zones sub-arctic and sub-antarctic

8. Question?
If diatoms and coccolithophores did not evolve until Jurassic time what was the major primary producer in the Paleozoic?
Dinoflagellates (Silurian-Recent)
Acritarchs (Precambrian-Early Mesozoic)
(~2.0 b.y.a)

9. Dinoflagellates Kingdom: Protista
Division: Pyrrophyta “flame-colored algae” “fire algae”
Class: Dinophyceae
Have both “plant” and “animal” characteristic.
Unicellular biflagellate algae
Most photoautotrophs
Some are heterotrophic (predaceous or parasitic)
Normally don’t occur below 50 m
Use flagella to stay up in water column
Marine and freshwater habitats

10. Red tides (Dinoflagellate blooms)
Mostly planktonic
Some benthic species
Red tides (Dinoflagellate blooms)
Neural toxin
Population controlled by N, P, Fe, light
Geologic Range
Silurian-Recent
Common Permian – Recent as cysts.

11. Single layer wall with central cavity.
Acritarchs
Kingdom: Protista
Division: Acritarcha
Organic-walled protists of uncertain phylogenetic, ecological placement that are the most common plankton preserved in Paleozoic rocks.
Most mm
Single layer wall with central cavity.
Known from Gunflint Chert (~2.0 b.y.)

12. Primary Consumer/Protista
Radiolarians
Kingdom Protista
Phylum Sarcodina
Class Actinopoda
Subclass Radiolaria
Geologic range (Cambrian to Recent)
Exclusively marine zooplankton
Spherical cells with pseudopodia (“false feet”)
Used to capture prey “micro-omnivores”
Some symbiotic with zooxanthellae “aid in nutrition”
Maintain bouyancy using fats or gases held within cell or spines

13. Skeleton endoskeleton of Opal-A Even the spines
Hard parts are never in direct contact with seawater while they are alive.
Porous skeleton, Why?
For diffusion to nutrients and waste
For strength and light weight
Reproduction asexual mainly binary fission.
Life span days to weeks to months

14. Ecology and Distribution
Most diverse and abundant in equatorial upwelling regions (up to 82,000/m3)
Also abundant in polar upwelling regimes and there abundant is diluted by the even more abundant diatoms.
Factor important in ooze deposition?
Production
Dissolution
Dilution
Found from the surface down to 5000m alive, most in upper few hundred meters.
Greatest net accumulation is deep equatorial Pacific.

15. Forams Kingdom Protista Geologic range
Phylum Sarcodina
Class Rhizopoda
Order Foraminiferida “foramen” bearing
Chambered protists in which the chambers are connected by internal pore.
Geologic range
Benthic forms: Cambrian to Recent
Planktonic forms: Triassic to Recent
Mainly marine, some brackish and freshwater species
Occur at all depths and all latitudes

16. Benthonic forams (1000’s of species)
Sessile or vagrant using pseudopodia
Live in the interstitial water within the sediment or on the sediment surface.
Planktonic forams (~30 species)
Usually globose with inflated test.
e.g., Globigerina
Nutrition “Micro-omnivores” like radiolarians
Use pseudopodia to capture food
Phagocytosis “like ameba relatives”.
Some symbiotic with zooxanthellae
Aid to nutrition and calcification

17. Skeleton Endoskeleton or test Mineralogically tests can vary.
Three different types
Agglutinated forams, use cement to built a test of sand or silt-size grains .
Calcareous forams, mostly calcite either low or high-mg calcite.
Some very rare siliceous forams .

18. Diverse Test Morphologies
Uniserial
Single series of chambers
Biserial
Double row of chambers
Triserial
Triple row of chambers
Coiled
Planispiral
Coiled in a single plane or axis
Trochospiral
Translation along a vertical or second axis
Ecophenotypic variation (environmental phenotypes)

19. Reproduction Show alternation of sexual and asexual forms
Dimorphic test forms
Gammont generation (N) – undergoes sexual reproduction
Schizont generation – undergoes asexual reproduction
Asexually produced forms have a large initial chamber, but smaller overall test called “Megalospheric”
Sexually produced forms have a small initial chamber, but larger overall test called “Microspheric”
Some show brooding of young in shell interior
“Commonly seen in fossil record”

20. Ecological uses
Benthic forams are zoned according to numerous variables including:
Substrate
Light
Temperature
Oxygen
Salinity
Benthic forams are excellent paleoenvironmental indicators in the fossil record.
Planktonic forams are excellent index fossils.

21. Evolution through Geologic Time
Most Paleozoic forms had aggulutinated test.
Proteinaceous forms first
Then agglutinated test
Then calcareous tests by increasing the amount of cement over time. (Did not become common until Devonian time)
Paleozoic fusulinids (large forams) “rice grains”
~5,000 species some up to 10 cm long!!!
Go extinct end-Permian
Tertiary nummulites (5-20 mm) post-Eocene decline
Found in the ancient Pyramids.

22. In each case the development took place in low paleolatitudes.
The fossil record suggest the “larger foraminifera” evolved at least four times during the Mesozoic and Cenozoic, each event representing the acquisition of symbiosis.
In each case the development took place in low paleolatitudes.
Four independent acquistions therefore not good time indicators.
Example, of iterative evolution.