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Fossil Protista. Kingdom Protista Phylum Sarcomastigophora Subphylum Sarcodina Class Granuloreticulosa Subclass Rhizopoda Order Foraminifera Suborder Allogrominna simple, organic
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Kingdom Protista Phylum Sarcomastigophora Subphylum Sarcodina Class Granuloreticulosa Subclass Rhizopoda Order Foraminifera Suborder Allogrominna simple, organic Suborder Textulariina agglutinated sand Suborder Lagenina uniserial sac-shaped Suborder Fusulina large spindle-shaped Suborder Miliolina imperforate porcelaneous calcite Suborder Rotaliina hyaline multichambered spirals Suborder Globigeriina bubble-shaped spirals Subclass Radiolaria Order Spumellaria spherical symmetry Order Nasellaria conical symmetry Division Chrysophyta (“golden brown algae”) Class Bacillariophyceae diatoms Class Coccolithophyceae coccolithophorids (calc. nannofossils)
Protoplasm Pseudopodia Algal symbionts Test
Foraminifer Tests – geometric patterns of overlapping chambers Cushman Foundation
Foram Evolution • Cambrian - agglut. cylindrical tubes • Silurian – enrolled tubes • Devonian – multichambered agglut. forms • Carboniferous – bi-, triserial, and trochospiral forms, agglut. and calcitic (appearance of miliolines & lagenines) • Carb-Perm – Fusulinaceans – large “grain of wheat” shaped • Mesozoic – benthics diversify and spread to all modern habitats • Planktonics first appear in mid Jurassic • 3 sp. of planktonic survived K/T, diversified in Cenozoic • Large Rotaliines (nummulitids, discocyclinids, lepidocyclinids) up to 3 cm developed • E/O extinction • Good examples of iterative evolution, convergent evolution
Nassellaria - conical Spumellaria - spherical
Radiolarian Ecology • Marine – depths less than 1000m (usually < 100m with symbiotes) • Species are depth zoned • Zonation may be more temperature than depth • Distribution in seds eflects the CCD • Used in CLIMAP • Apparently reproduce by asexual cloning Radiolarian Evolution • Cambrian to Recent • Depth zonation by Silurian • Strongly affected by Permo-Triassic ext. but not by K/T • First Nassellarians inTriassic • Diversity peaked in Cretaceous and late Cenozoic • Many morphotypes may be ecophenotypic variants
DIATOMS Test = frustule Radial symm = Centrales Bilateral symm = Pennales
Diatom Ecology • Marine & fresh – depths less than 100m (photosynthetic algae) • Important in Food Chain • Most of life repro asexually - getting smaller as new valve fits inside old • When too small repro sexually • resting spore stage - statospore • common in upwelling, cold waters, good indicators of paleoenvironment Diatom Evolution • Jurassic to Recent • High diversity by Cretaceous suggests unpreserved prior history • Unaffected by K/T • Trend toward reduced silica
Coccolithophores Coccoliths Coccospheres
Coccolith Ecology • Shallow marine (<200m), most are euryhaline • Temperature zonation • Distribution reflects CCD and “fecal express” • Very small - coccosphere can fit inside a foram test • Coccoliths formed in interior vesicles • Coccoliths are not necessarily species specific • Single species may have different types in layers • Most repro by asexual fission • Some have alternating flagellated motile and non-motile stages • May have sexual repro Coccolith Evolution • (Paleozoic ?) Late Triassic to Recent • Decimated by K/T – 15-18 species survived • Present day diversity at a minimum • 1 Species may have several morphotypes