KINGDOM: Chromista - Webs · Fossils to ID 2016 - Set D.doc 2 of 19 1/21/2016 10:26:00 PM KINGDOM:...

Fossils to ID 2016 - Set D.doc 1 of 19 1/21/2016 10:26:00 PM

KINGDOM: Chromista

Class: Bacillariophyceae (DIATOMS)

Common Name or members: Diatoms (‘cut in two’ in Greek)

Habitat: Marine, Freshwater

Periods of Existence: Early Jurassic to PRESENT

Description: Diatoms are microscopic, single-celled, geometrically-shaped phytoplankton responsible

for generating a huge proportion of the oxygen in our current atmosphere. Diatoms have a shell-like

‘frustule’ or test made out of silica (glass) with two interlocking halves that fit together like a pillbox or

petri dish.

Because they depend on sunlight for photosynthesis, diatoms generally live in the upper 200 meters

of oceans and bodies of fresh water. Most diatoms are non-motile, as their relatively dense cell walls

cause them to readily sink. Planktonic forms in open water usually rely on turbulent mixing of the

upper layers by the wind to keep them suspended in sunlit surface waters. Some species actively

regulate their buoyancy with intracellular lipids to counter sinking. These lipids or oils are a primary

source for petroleum and natural gas fossil fuels.

Where dissolved silicates are available in the oceans (in cold areas), diatoms proliferate to enormous

proportions. As they die and float to the ocean bottom, they form a ‘siliceous ooze’ that covers large

areas of the deep ocean floor and eventually becomes lithified to form chert, diatomite, and

diatomaceous earth (a white powder) that is used as an abrasive and an eco-friendly insecticide. The

sharp, broken edges of the diatom frustules cut into the exoskeleton of insects, causing them to

dehydrate to death!

Freshwater Diatom Marine Diatom

https://en.wikipedia.org/wiki/Motility

https://en.wikipedia.org/wiki/Turbulence

https://en.wikipedia.org/wiki/Wind

https://en.wikipedia.org/wiki/Lipid


KINGDOM: Plantae

Common Name or members: Plants

Habitat: Terrestrial

Description: Land-based autotrophs with cell walls of cellulose that experience an alternation

of generations.

Phylum: Anthophyta

Common Name or members: flowering plants

Periods of Existence: Early Cretaceous - PRESENT

Description: A clade of seed plants bearing flower-like structures, most of which are

angiosperms (‘vessel-seeds’ in Greek) – the flowering plants. Angiosperms have complex leaf

veins, fruits, and flowers. The flowering plants have been phenomenally successful, replacing

conifers as the dominant trees by the end of the Cretaceous. The ‘great angiosperm radiation’

resulted in over 90% of current plant life, including virtually all plant-based foods and almost

every plant you can think of other than conifers.


Acer (Maple Tree)

Populus (Poplar Tree)


Platanus (Plane Tree, Sycamore)


Phylum: Ginkgophyta

Common Name or members: Ginkgos, Maidenhair Tree

Periods of Existence: Jurassic to PRESENT

Description: Ginkgos are a group of large trees related to gymnosperms. The only living

species, Ginkgo biloba (‘maidenhair tree’), is a living fossil which is native to China but has in

modern times been planted all over the world. Ginkgo is a misspelling of the Japanese kanji

word for ‘silver apricot’.

Ginkgo (Maidenhair Tree)


Phylum: Lycopodiophyta

Common Name or members: Lycopsids, Club Mosses, Scale Trees

Periods of Existence: Late Silurian to PRESENT

Description: Lycopsids are the oldest living division of vascular plants. They reproduce by

spores rather than seeds, and their leaves have only a single vein (versus the complex veins of

seed plants) that grew out of the entire surface of the trunk and branches but which fell off

the lower portion of the tree as the plant grew, leaving ‘leaf scars’. Most Lycopsids are now

extinct and those remaining are quite small, but they dominated the Carboniferous forests as

tall trees and formed much of our fossil coal deposits. The tree Lepidodendron had four large

root-like rhizomes that were technically subterraneous branches rather than true roots.

Lepidodendron (Scale Tree)


Phylum: Pinophyta

Common Name or members: Conifers (‘cone-bearing’ in Latin)

Periods of Existence: Late Carboniferous to PRESENT

Description: Cone-bearing seed plants most with leaves like needles and most forming large

trees. Pinophyta were the dominant land plants of the Mesozoic, but they now dominate only

cool-climate areas.

Conifers include the living fossil Metasequoia gylptostoboides (‘dawn redwood’ in Latin), the

sole living species of its genus. It was thought to be extinct until the discovery in 1944 of a

small stand of trees in a remote part of China. Since then the towering tree (reaching 200

feet) has been cultivated and planted all over the world. Although dawn redwoods have

needles rather than leaves, surprisingly, they lose them during winter, similar to angiosperm

trees.

Metasequoia (Dawn Redwood)


Phylum: Pteridophyta

Common Name or members: Ferns and Horsetails

Periods of Existence: Late Devonian to PRESENT

Description: A group of primitive seedless vascular plants including ferns - with multipart leaves like

fronds and horsetails – with whorls of needle-like leaves on a ribbed, central stalk. Pteridophyta bear

spores (ferns on the undersides of their leaves, horsetails in cones) and spread by underground stems

called rhizomes allowing for the growth of many clones of a single individual.

Ferns and horsetails dominated the understory of Paleozoic and Mesozoic forests and contributed

substantially to the fossil coal formed in those periods.

The 15 living species in the genus Equisetum (‘horsetails’ in Latin) are all that remain from a group

common to the late Paleozoic coal forests and well represented in coal-related fossils. Horsetails

were medium-sized trees growing up to 100 feet tall during the Paleozoic and Mesozoic, but are now

found only as small plants and trees. Their stems/trunks were hollow, so they fossilize as internal

molds (calamites – ‘stalk’ in Latin). For many years paleontologists did not realize that the fossil

leaves (annularia – ‘rings’ in Latin) were different parts of the same tree.


Calamites (internal molds of trunk of

horsetail)

Annularia (leaves of

horsetails)


Phylum: Pteridospermatophyta

Common Name or members: ‘Seed Ferns’ in Greek

Periods of Existence: Carboniferous to Cretaceous (EXTINCT)

Description: Extinct seed-bearing plants that flourished in the Carboniferous and Permian

forests and included Glossopteris - which was critical to proving Alfred Wegener’s theory of

Continental Drift and the existence of the supercontinent Pangea. Glossopteris (‘tongue fern’

in Greek) reached almost 100 feet in height and flourished in the Permian before extinction in

the end-Permian extinction event. Glossopteris fossils have been found in all of the four

continents that formed the Gondwana, Southern part of Pangea. Glossopteris shed its leaves

seasonally, so leaf fossils are common, but no large portion of the plant has ever been found,

so we can only guess at what it looked like.

Glossopteris (‘Tongue Fern’ in Greek)


TRACE FOSSILS (Ichnofossils)

Trail (Trilobite Trail ‘Cruzziana’)

Footprint (Theropod)

Trackways (Iguanodon)


Borings

Worm Burrow Casts

Tubes (worms)

Predation Marks

(bite marks)


Repair Scars

Nests

Eggshells


Coprolites (fossilized

poop/feces)

carnivore

herbivore

Stromatolite

Amber/Copal


Petrified Wood

Trapped in Asphalt

Mummification


SEDIMENTARY ROCKS

Coquina

Diatomite

Limestone


Chalk (a form of limestone)

Fossiliferous Limestone

Sandstone


Shale

Siltstone

Banded Iron Formations (BIFs)


Coal (Bituminous)

Coal (Anthracite)

Petroleum (fossilized diatom oil)

Asphalt or Bitumen (petroleum that has lost volatiles)

KINGDOM: Chromista - Webs · Fossils to ID 2016 - Set D.doc 2 of 19 1/21/2016 10:26:00 PM KINGDOM:...

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