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| |Mode= Most of them lived benthically, but some may have been pelagic or planktonic. Most of them were detritus feeders, but some may have been active predators and scavengers. They lived in shallow seas. After the Ordovician, they moved from shallow water to deep water. | | |Mode= Most of them lived benthically, but some may have been pelagic or planktonic. Most of them were detritus feeders, but some may have been active predators and scavengers. They lived in shallow seas. After the Ordovician, they moved from shallow water to deep water. |
| |Adapt= | | |Adapt= |
− | |Distr= | + | |Distr= Worldwide. |
| |Common= Trilobites | | |Common= Trilobites |
| |Misc= They are good index fossils. Most fossils are shed skeletons filled with sediment (internal molds). Trilobite comes from tri + lobe + ite, meaning "three lobes." This is the major class of arthropods competitors will be asked about.}} | | |Misc= They are good index fossils. Most fossils are shed skeletons filled with sediment (internal molds). Trilobite comes from tri + lobe + ite, meaning "three lobes." This is the major class of arthropods competitors will be asked about.}} |
Revision as of 14:38, 18 October 2020
- Main article: Fossils
Kingdom Animalia
Sponges (Phylum Porifera)
Picture(s)
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Common Names
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Sponges
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Physical Description
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Their bodies do not contain tissue, muscles, nerves, or organs. Some are composed of silica spicules, and others of calcium carbonate. They generally do not have body symmetry, but some sponges have radial symmetry. Their bodies are hollow and held together by jelly-like substances which have many cells. Cells on the outside can move inwards and change function. Their pores are called ostia.
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Fossil Range
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Precambrian to Recent. Sponges reached their greatest diversity during the Cretaceous period.
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Taxonomy
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Kingdom: Animalia.
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Mode of Life or Habitat
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They are benthic and sessile, and live in marine and freshwater environments. Sponges are free-swimming in their larval stages. Sponges can have a symbiotic relationship with blue-green algae (shallow sponges are more likely to do this). Sponges can be reef builders, being able to house organisms such as nematodes, crustaceans and mollusks in the osculum (center chamber).
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Adaptations Over Time
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They were the first to branch off from the common ancestor of all animals, so they're the sister group of all other animals. The shapes of their bodies are adapted for maximal efficiency of water flow through the central cavity. Some specimens can move at around 1-4 mm a day.
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Distribution
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Sponges are worldwide in their distribution, living in a wide range of ocean habitats.
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Additional Information
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They pump water through the body to feed, and have one body orifice to serve for ingestion as well as excretion.
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Genus Astraeospongia (calcareous sponge)
Picture(s)
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Fossil Range
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Silurian to Devonian
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Mode of Life or Habitat
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It lived in marine environments.
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Additional Information
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The spicules were the only part of the sponge that got fossilized, and there are star-shapes spicules all over the body (though they can be faint). The pores of the sponge are called Ostium.
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Genus Hydnoceras (glass sponge)
This fossil will only be tested at the State and National levels.
Picture(s)
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Common Names
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Glass sponge (this name refers to all of class Hexactinellida).
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Physical Description
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It is composed of silica spicules, which provided structural support and deterred enemies.
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Fossil Range
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Devonian to Pennsylvanian
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Taxonomy
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Class: Hexactinellida
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Mode of Life or Habitat
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Reef builder.
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Distribution
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Eastern United States and Europe
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Additional Information
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Class Hexactinellida is still extant but is now found only in the deep ocean. In the past, they could be found at almost all depths. Hydnoceras is a good index fossil and is usually preserved as internal molds.
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Bryozoans (Phylum Bryozoa)
Picture(s)
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Common Names
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Moss animals
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Physical Description
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The structure seen when looking at a Bryozoan is actually a support structure composed of calcium carbonate. The animal itself lives in tiny holes in that structure, and is rarely larger than a millimeter. They appear very similar to corals, but are very, very different in biology. Bryozoans come in three growth forms: massive (a mound with no planned shape), branching (where the structure forms intricate branches), and fenestrate (where in life the bryozoan would have large, soft appendages coming out from the skeleton).
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Fossil Range
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They evolved in the Ordovician, and are still found today. Are most commonly found in Paleozoic rocks
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Taxonomy
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Kingdom: Animalia Clade: Lophophorata
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Mode of Life or Habitat
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They attached to the bottom of the ocean, and were filter feeders.
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Distribution
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Bryozoans are found on every continent except Antarctica. Most lived in a shallow marine environment, but nowadays can also be found in fresh water.
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Additional Information
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The produce a compound known as bryostatin 1, which is currently being tested as an anti-cancer drug. Bryozoans can reproduce both sexually and asexually.
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Genus Archimedes
Picture(s)
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Physical Description
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It was a fenestrate bryozoan that was much wider in life than it seems from the fossil. Individual animals are called zooids. Fossils are ~2 cm long. In life, it had calcified tissue that held the edge of the lacy colony with the axis usually preserved alone.
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Fossil Range
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Carboniferous to Permian, ~345-268 mya.
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Taxonomy
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Class: Stenolaemata Order: Fenestrata Family: Fenestellidae
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Mode of Life or Habitat
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Benthic and sessile filter feeders. Lived in clear, shallow marine waters. They preferred clear water because murky water clogs the zooecia in which they live.
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Distribution
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Are mainly found throughout Europe and North America, but they have also been found in sediments of Afghanistan, Canada, Russia, and Australia. They lived in shallow marine waters.
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Additional Information
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It was named for the Greek thinker Archimedes, who invented the water screw - Genus Archimedes looks very much like a screw.
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Genus Rhombopora
Picture(s)
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Physical Description
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A branching bryozoan. Has a calcified skeleton made of tubes. Individual zooids form zooeciums, sacs that they secrete and live in. They attach to the substrate via a holdfast structure.
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Fossil Range
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Carboniferous to Permian.
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Taxonomy
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Class: Stenolaemata Order: Rhabdomesida Family: Rhomboporidae
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Mode of Life or Habitat
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Benthic and sessile filter feeders. Lived in clear, shallow marine waters.
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Distribution
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Widespread across North America and Asia.
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Additional Information
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The genus name comes from its rhombus-shaped holes.
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Graptolites (Phylum Hemichordata)
This fossil will only be tested at the State and National levels.
Picture(s)
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Common Names
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Graptolites
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Physical Description
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Fossils look like pencil marks on a rock. They consisted of colonies of microscopic organisms with a threefold body division. The three body parts are the proboscis/protostome, the collar, and the trunk. Each colony comes from an initial zooid (the sicular zooid). Every other zooid then develops from that initial zooid. The colony is connected via tubes called stolons. The entire colony is housed in a theca, also called a rhabsodome, coenocium, or tubarium, likely made of either collagen or chitin, which the graptolites secrete through the cephalic shield.
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Fossil Range
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Cambrian to end of Carboniferous.
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Taxonomy
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Kingdom: Animalia Clade: Ambulacraria
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Mode of Life or Habitat
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Usually deposit feeders, though some species are filter feeders.
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Adaptations Over Time
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They are thought to be on the path that led to the vertebrates.
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Distribution
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Worldwide - excellent index fossils for the Paleozoic.
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Additional Information
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Geologists can divide the rocks of the Ordovician and Silurian periods into graptolite (class Graptolithina) biozones; these are generally less than one million years in duration. A worldwide ice age at the end of the Ordovician eliminated most graptolites except the neograptines. Diversification from the neograptines that survived the Ordovician glaciation began around 2 million years later. Some of the greatest extinctions that affected the group were the Hirnantian in the Ordovician and the Lundgreni in the Silurian, where the graptolites populations were dramatically reduced. They are usually fossilized by means of carbonization in shale.
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Order Dendroidea (benthic graptolites)
This fossil will only be tested at the State and National levels.
Picture(s)
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Common Names
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Benthic Graptolites
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Physical Description
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They were upright and bushy. They are many-branched, with numerous small thecae (two kinds of thecae, autothecae and bithecae, probably female and male zooids, respectively). They have colonial skeletons (rhabdosomes) that are generally broadly branching (conical to fan-shaped to shrub-like to flat spirals). Stipes branch many times in sequence, yielding a dendritic rhabdosome. The nema attaches the rhabdosome to the substrate.
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Fossil Range
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Middle Cambrian to Lower Carboniferous
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Taxonomy
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Class: Pterobranchia Subclass: Graptolithina
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Mode of Life or Habitat
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Sessile, Benthic, Attached to substrates, as encrusting organisms or by an attachment disc. Suspension Feeder.
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Distribution
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Worldwide.
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Additional Information
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Graptolites with relatively few branches were derived from Dendroidea at the beginning of the Ordovician period.
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Order Graptoloidea (planktic graptolites)
This fossil will only be tested at the State and National levels.
Picture(s)
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Common Names
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Planktic Graptolites.
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Physical Description
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One type of thecae (autothecae). In adults, there is always a sicula bearing a nema. Typically resemble small hacksaw blades. Each "tooth" of the hacksaw blades housed a tentaculate, filter-feeding organism. The entire hacksaw blade is the graptolite skeleton, known as a rhabdosome, a non-mineralized colonial skeleton. Stipes branch at most once. In some, the stipes are scandent (they grow up the sides of the nema). The nema attaches the rhabdosome to a floating object. (Some genera seem to have secreted siphonophore-style floats from which numerous rhabdosomes hung.) Thecae are uniform. Monograptid morphology an unbranched stipe growing up one side of the nema. Such rhabdosomes often assume spiral shapes. Perhaps they did not attach and depended on a slow sinking rate to remain in the photic zone.
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Fossil Range
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Lower Ordovician to Lower Devonian (peak abundance and diversity from Ordovician to Silurian, as they had a partial die-out in the early Devonian).
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Taxonomy
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Class: Pterobranchia Subclass: Graptolithina
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Mode of Life or Habitat
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Planktonic/Pelagic. Drifted freely on the surface of early seas. They were the most important animal members of the plankton during the time of their peak. Suspension Feeder.
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Adaptations Over Time
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They had 8 stipes in earlier forms but 2 and then 1 in later forms.
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Distribution
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Worldwide.
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Additional Information
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More diverse than Dendroidea. Includes five suborders. Key index fossils. Graptoloidea appeared during the Great Ordovician Biodiversification Event (GOBE), which followed the late Ordovician extinction.
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Corals (Phylum Cnidaria)
Picture(s)
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Common Names
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Includes jellyfish, corals, and hydras.
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Physical Description
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Cnidarians use nematocysts to catch prey and have tissue “organs.” They are radially symmetric with a sac-like body. Coral has skeletal cups known as corallites. The inside of the corallite is called the calyx. The vertical blades in the calyx are known as septa which may continue outside the corallite wall as costae.
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Fossil Range
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Ediacaran (Precambrian, ~580 mya) to modern-day.
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Taxonomy
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Kingdom: Animalia
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Mode of Life or Habitat
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Usually marine. Polyps (e.g. corals) are benthic and sessile. Jellyfish are motile and planktonic.
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Additional Information
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The cnidarian group contains jellyfish, sea anemones, and corals. They all use stinging cells known as nematocysts to capture prey, which is usually plankton. Modern corals have a symbiotic relationship with algae.
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Order Tabulata (tabulate corals)
Picture(s)
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Common Names
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Tabulate Corals
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Physical Description
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They form colonies of hexagonal cells (corallites), with a calcite skeleton. They have well-developed horizontal internal partitions (tabulae) within each cell, but reduced or absent vertical internal partitions (septa). They vary in shape with their platforms usually straight and complete. Tabulate corals also display radial symmetry, and the septa, if present, are always very short and prickly.
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Fossil Range
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Ordovician to Permian. They became extinct in the Permian–Triassic extinction event.
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Taxonomy
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Class: Anthozoa
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Mode of Life or Habitat
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They were almost always colonial. Shallow waters.
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Additional Information
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Preserved by limestone and calcareous shale.
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Genus Favosites
Picture(s)
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Common Names
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Honeycomb coral.
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Physical Description
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A specimen can be anywhere from a few centimeters to tens of centimeters in all dimensions. Is easily recognizable by the honeycomb-like appearance when viewed from above. Corallites (individual structure that houses each coral animal/polyp) were about 1/16 in (2mm) wide and in length they were long, narrow, closely packed tubes. They were colonial. Septa are not present or are short irregular spines. Mural pores in the walls of the corallites allow transfer of nutrients from polyp to polyp. Filter-fed on plankton using stinging tentacles. Calcium carbonate substrate.
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Fossil Range
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Late Ordovician to Late Permian, 488-251 mya. It is commonly found in Silurian limestone.
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Taxonomy
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Family: Favositidae
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Mode of Life or Habitat
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Benthic and sessile. Lived in warm, shallow, and sunlit seas.
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Adaptations Over Time
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They had a symbiotic relationship with photosynthetic algae.
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Distribution
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Every continent except Antarctica.
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Additional Information
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Rising sea levels during the Devonian caused them to become less common. The name comes from favus, Latin for "honeycomb."
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Genus Halysites
This fossil will only be tested at the State and National levels.
Picture(s)
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Common Names
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Chain coral, due to its growth pattern.
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Physical Description
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Made of calcite. Individual corallites were cylindrical and 2 mm long and wide. Each corallite held a single polyp. Corallites are more widely spaced in Halysites than in many other tabulate corals. Distinctive chain shape. Colonies range in diameter from <1 to 10s of centimeters.
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Fossil Range
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Late Ordovician to Early Devonian, 450-412 mya. They thrived in the Silurian.
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Taxonomy
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Family: Halysitidae
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Mode of Life or Habitat
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Benthic and sessile. Lived in warm, shallow waters. Suspension feeder.
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Adaptations Over Time
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They had a symbiotic relationship with hermit crabs and algae.
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Distribution
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Widespread over North America. They have been found in sediments of Canada, the US, Europe, Asia, and Australia.
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Additional Information
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It is an index fossil for the Silurian. The name comes from halysis, Greek for "chain."
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Order Rugosa (rugose corals)
Picture(s)
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Common Names
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Tetracorals, horn corals, and cup corals.
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Physical Description
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Shape of a wrinkled horn. May be solitary or colonial. Could grow up to 1 meter long. Large corallites. They have well-developed septa in groups of four (modern corals have groups of six, subclass Hexacorallia). They have a skeleton made of calcite. They have bilateral symmetry. Probably had stinging tentacles to capture prey. Have well-developed tabulae. They sometimes possess dissepiments, curved plates that connect the septa and tabulae. They start with four major septa and then grow minor septa. The central line is called the columella, which gives support for solitary corals.
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Fossil Range
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Middle Ordovician to Late Permian.
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Taxonomy
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Class: Anthozoa
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Mode of Life or Habitat
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Shallow water. Benthic, sessile micro-carnivores.
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Adaptations Over Time
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Some lived inside Stromatoporoidea sponges (endosymbiosis), especially in the Silurian.
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Additional Information
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Name comes from rūgōsus, Latin for "wrinkled."
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Genus Heliophyllum (horn coral)
Picture(s)
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Common Names
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Horn coral.
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Physical Description
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~3 cm long horns. May be solitary or colonial. It fed using its nematocysts to stun prey.
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Fossil Range
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Devonian.
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Taxonomy
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Family: Zaphrentidae
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Mode of Life or Habitat
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Shallow waters. Benthic and sessile.
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Distribution
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They had a wide distribution, including both Americas, Asia, and Europe.
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Additional Information
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Heliophyllum growth patterns are used to calculate the length of the Devonian day and year. Horn corals get their name from their body shape, which is horn-like.
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Genus Hexagonaria
Picture(s)
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Physical Description
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Bilateral symmetry. Thick walls and septa with hexagonal corallites. Colonial. Each corallite of the Hexagonaria is made up of a usually six-sided compartment that adjoins the others in the colony and creates an elaborate hexagon.
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Fossil Range
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Devonian, 416-359 mya
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Taxonomy
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Family: Disphyllidae
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Mode of Life or Habitat
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Warm, shallow waters. Benthic and sessile.
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Distribution
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It was very widely distributed around the world.
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Additional Information
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Petoskey stones (H. percarinata fossils) are the state stone of Michigan. Formed through glaciation, where stones were plucked from the bedrock and grinded into smooth rocks, eventually deposited into the northwestern portion of Michigan’s lower peninsula.
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Order Scleractinia (stony corals)
Picture(s)
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Common Names
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Stony corals, hard corals. A type of hexacoral.
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Physical Description
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Radial symmetry. The skeleton of an individual scleractinian polyp is known as a corallite. All modern scleractinian skeletons are composed of calcium carbonate in the form of crystals of aragonite. Well-developed septa. Absent tabulae.
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Fossil Range
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Middle Triassic - Recent. Scleractinian corals are the only corals that are alive today.
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Taxonomy
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Class: Anthozoa Subclass: Hexacorallia
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Mode of Life or Habitat
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Although some species are solitary, most are colonial. Hermatypic corals (the world’s primary reef builders) live in shallow tropical waters and are mostly colonial while ahermatypic corals live in all regions of the ocean, are either colonial or solitary, and do not build reefs.
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Distribution
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Occur in all oceans.
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Additional Information
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Polyps reproduce asexually by budding. The name Scleractinia is New Latin, based on Ancient Greek σκληρός (sklērós, “hard”) + ἀκτίς (aktís, “ray”).
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Genus Septastrea
Picture(s)
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Physical Description
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The corallites are around 6 mm long. The polyps have horn shapes and 6 long and 6 short septa. Septastrea did not form reefs. Their morphology is variable, being able to grow into just about any shape.
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Fossil Range
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Paleogene to Pleistocene.
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Taxonomy
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Family: Rhizangiidae
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Mode of Life or Habitat
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Benthic and sessile. Usually lived in shallow, warm water, but were able to survive in deeper, colder water. Azooxanthellae (they do not live in symbiosis with photosynthetic algae). Suspension feeder.
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Distribution
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Every continent except Antarctica. Very prevalent along the Atlantic Coastal Plain.
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Class Scyphozoa
This specimen is not on the official 2020-2021 Fossil List but has been on the Fossil List in the past.
Picture(s)
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No pictures have been added as of yet.
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Common Names
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True jellyfish.
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Physical Description
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Bell-shaped bodies. Mostly water and therefore rare as fossils. Mesoglea support structure. Four-part symmetry (four bodies of tissue, or septa, and four pouches around a central stomach). 2-4 cm in diameter but can grow up to 2 m.
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Fossil Range
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Precambrian to present-day.
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Mode of Life or Habitat
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Jellyfish have a polyp stage which is sessile and a medusa stage which is planktonic.
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Arthropods (Phylum Arthropoda)
Picture(s)
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Common Names
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Arthropods
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Physical Description
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They are invertebrates and have segmented bodies, an exoskeleton, and many limbs. The exoskeleton is made of chitin and sometimes calcium carbonate.
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Fossil Range
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Cambrian - Recent.
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Taxonomy
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Kingdom: Animalia
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Distribution
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Almost anywhere
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Additional Information
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This is the phylum that contains the "creepy-crawlies" of today. Arachnids, insects, and the like are all arthropods.
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Subphylum Crustacea (shrimp, lobster, crabs, barnacles, ostracods)
This fossil will only be tested at the State and National levels.
Picture(s)
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Common Names
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Crustaceans
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Physical Description
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Crustaceans use antennae for swimming. They have 2-parted limbs and a chitin shell. Their bodies are divided into the head, thorax, and abdomen (sometimes referred to as the cephalothorax and abdomen). They have gills to obtain oxygen. They have 2 pairs of sensory antennae and 3 pairs of limbs used to push food into the mouth. They moult their exoskeleton in order to grow. They have an open circulatory system.
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Fossil Range
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Cambrian - Recent. They became abundant during the Carboniferous.
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Mode of Life or Habitat
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They are mostly marine animals, though some are common in freshwater and some are partially terrestrial. They can be benthic, planktonic, nektonic, or pseudo-planktonic.
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Class Malacostraca
This specimen is not on the official 2020-2021 Fossil List but has been on the Fossil List in the past.
Picture(s)
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No pictures have been added as of yet.
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Common Names
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Crabs, lobsters, shrimp, etc.
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Physical Description
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Have segmented body parts (8 segments in the thorax, 6-7 segments in the abdomen). They have antennae, compound eyes on stalks, and their head and thorax are usually covered by a carapace.
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Fossil Range
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Evolved during the Cambrian explosion.
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Mode of Life or Habitat
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They are generally marine animals, but some live in freshwater or are terrestrial.
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Class Maxillopoda
This specimen is not on the official 2020-2021 Fossil List but has been on the Fossil List in the past.
Picture(s)
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No pictures have been added as of yet.
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Common Names
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Barnacles, copepods, fish lice, and tongue worms.
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Physical Description
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They have small, short bodies. They usually lack appendages and have special mouthparts called maxillae for tasting and feeding.
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Fossil Range
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Middle Cambrian to present-day.
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Mode of Life or Habitat
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Deposit feeders.
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Distribution
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Worldwide.
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Additional Information
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"Maxillopoda" means jaw foot. It is polyphyletic.
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Infraclass Cirripedia
This specimen is not on the official 2020-2021 Fossil List but has been on the Fossil List in the past.
Picture(s)
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No pictures have been added as of yet.
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Physical Description
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Circular with shells made of calcite.
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Fossil Range
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Evolved during the Cambrian but did not become common until the Neogene.
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Mode of Life or Habitat
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Live in shallow and tidal seawater. Sessile but with 2 motile larval stages. They attach to an object permanently. Can be filter-feeders or parasitic.
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Additional Information
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"Cirripedia" means curl foot.
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Subphylum Chelicerata
Picture(s)
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No pictures have been added as of yet.
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Common Names
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Sea spiders, arachnids, and eurypterids.
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Order Eurypterida (eurypterids)
Picture(s)
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Common Names
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Sea scorpions
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Physical Description
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Eurypterids have abdomens with 7 segments, 8 legs with the last pair being paddle-like, and tails. They are the largest-known arthropods ever to exist, the largest measuring in at 2.5 meters long or possibly more (although most were under 8 inches long).
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Fossil Range
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Middle Ordovician - Late Permian (Although the earliest fossils of eurypterids date back to the Ordovician, the level of complexity already exhibited by the group indicates that they evolved in the Cambrian). They suffered greatly during the Late Devonian extinction and became extinct during the Permian-Triassic extinction. Eurypterids were most diverse during the Devonian and Silurian periods.
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Taxonomy
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Class: Merostomata The eurypterids belonged to the same group that modern-day horseshoe crabs are classified in. As arachnids, they are related to modern day spiders and scorpions.
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Additional Information
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When they were first discovered, paleontologists thought that they were ancient catfish- it was seven years later that they became identified as arthropods. More detail is known about the external anatomy of eurypterids than any other group of fossils, and they are almost as well known as modern animals.
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Class Insecta (Insects)
Picture(s)
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Common Names
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Insects
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Physical Description
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Insects have antennae, heads, 3-part thoraxes which have 3 pairs of legs, and abdomens. They have chitin exoskeletons which must be shed periodically and are not mineralized unlike other arthropods. Most undergo metamorphosis with pupae as resting stages. Over time, they grew wings (in the Carboniferous) and modified mouthparts.
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Fossil Range
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Early Devonian to recent. By the Cretaceous, all modern forms of insects had appeared.
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Taxonomy
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Subphylum: Hexapoda
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Mode of Life or Habitat
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Terrestrial and freshwater. One of the first animals to adapt to land.
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Distribution
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Worldwide
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Additional Information
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Insects were not visibly affected by the extinction of the dinosaurs at the end of the Cretaceous. Insecta is Greek for "cut into pieces." Terrestrial insects are usually not fossilized because their exoskeletons are not mineralized.
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Class Trilobita (Trilobites)
Picture(s)
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Common Names
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Trilobites
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Physical Description
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The first image identifies the sections of a trilobite's body: 1- cephalon, 2-Throax, 3-pygidium. The second image identifies the lobes that gives trilobites their name: 1- Left pleural, 2-Axial, 3-Right pleural.
Trilobites are named for their bodies, which are divided into three lobes, which run longitudinally along the body. The trilobite's body is also divided into three sections. They had legs, which were probably made of chitin, and antennae. Trilobites had spikelike structures on each side of the cephalon known as "free cheeks", which fell off during molting.
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Fossil Range
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Cambrian to Devonian except the genus Proetida which lived until the Permian Mass Extinction. They were the most diverse at the end of the Cambrian.
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Taxonomy
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Subphylum: Trilobitomorpha
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Mode of Life or Habitat
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Most of them lived benthically, but some may have been pelagic or planktonic. Most of them were detritus feeders, but some may have been active predators and scavengers. They lived in shallow seas. After the Ordovician, they moved from shallow water to deep water.
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Distribution
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Worldwide.
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Additional Information
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They are good index fossils. Most fossils are shed skeletons filled with sediment (internal molds). Trilobite comes from tri + lobe + ite, meaning "three lobes." This is the major class of arthropods competitors will be asked about.
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Genus Cryptolithus
Picture(s)
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Common Names
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It is also known as the "lace collar trilobite", because the front edge of its cephalon looks somewhat like lace.
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Physical Description
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It was almost completely blind. It is easily identifiable by its long free cheeks, and its unbelievably squashed appearance. Cryptolithus was a small trilobite. The thorax has 6 segments.
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Fossil Range
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Ordovician
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Mode of Life or Habitat
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Probably just ate detritus on the bottom of the ocean.
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Additional Information
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Its name comes from Latin: Crypto means "hidden" and lithus means "stone."
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Genus Calymene
Picture(s)
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Physical Description
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It is typically 2 cm in length. They have a Holochroal eye. Most have 13 segments in the thorax, but some have 19 segments. The cephalon is the widest part of the oragnism. They are frequently preserved as tightly rolled fossils.
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Fossil Range
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Early Ordovician to Early Devonian. They were the most abundant in the Silurian.
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Mode of Life or Habitat
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They lived in a marine environment - both shallow and deep.
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Distribution
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North America, North Africa, and Europe.
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Additional Information
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It is the state fossil of Wisconsin. Its name means "beautiful crescent."
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Genus Elrathia
Picture(s)
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Physical Description
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It is identifiable by its small head and well-defined axial lobe. Its thorax has anywhere from twelve to seventeen segments.
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Fossil Range
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Middle Cambrian. Oldest trilobite on the list.
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Distribution
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It is widespread in Western US and North America. It is commonly found in the Wheeler Formation in Utah.
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Additional Information
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Its name is based off the town Elrath, Cherokee County, Alabama, where they were discovered.
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Genus Isotelus
This fossil will only be tested at the State and National levels.
Picture(s)
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Physical Description
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It was the largest trilobite- three species of Isotelus grew to almost a meter long, and Isotelus rex is world’s largest trilobite ever found as a complete fossil. It also possessed pits around the body that some think housed sensory hairs. The thorax had 8 segments. It had Holochroal eyes.
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Fossil Range
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Middle-Upper Ordovician
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Mode of Life or Habitat
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Shallow and deep marine.
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Distribution
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Restricted to Europe and North America
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Additional Information
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Isotelus maximus is Ohio’s state fossil.
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Genus Eldredgeops (formerly Phacops)
Picture(s)
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Physical Description
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It had schizochroal eyes, and a proparian facial structure. Its thorax had 11 segments.
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Fossil Range
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Late Middle to early Upper Devonian. It was the most abundant in Devonian - used as a index fossil for the Devonian period.
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Mode of Life or Habitat
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Warm, shallow seas.
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Distribution
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It is found in North America, Morocco, and USA.
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Additional Information
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Eldredgeops rana is Pennsylvania's state fossil. Fossils are commonly found rolled in a ball, probably for self protection.
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Brachiopods (Phylum Brachiopoda)
Picture(s)
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Common Names
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Lamp Shells
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Physical Description
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Brachiopods are a diverse group of lophophorates that are externally very similar to clams and other bivalves. They are divided into two groups- inarticulate and articulate.
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Taxonomy
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As lophophorates, their closest relatives are bryozoans.
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Class Inarticulata
Picture(s)
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No pictures have been added as of yet.
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Physical Description
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Most inarticulate brachiopods are less than 1 cm in size - smaller than articulate brachiopods. Their shells were composed of calcium phosphate. They lack the tooth and socket arrangement between the valves that is present in articulate brachiopods.
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Fossil Range
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Cambrian - recent.
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Mode of Life or Habitat
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Although they were originally shallow marine organisms, today's brachiopods are only found in the deep ocean. They could be either epifaunal or infaunal in nature, depending on the species. They were filter feeders.
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Distribution
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Worldwide
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Genus Lingula
Picture(s)
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Common Names
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Name means "Little Tongue" in Latin because of its thin, tongue-shaped shell.
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Physical Description
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It is known for having a very long pedicle, which anchored it to the sea floor. It can be detected by a short row of three openings through which it takes in water (sides) and expels it again (middle).
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Fossil Range
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Silurian to recent.
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Mode of Life or Habitat
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It lived in vertical burrows in intertidal areas and fed on detritus.
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Additional Information
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It is the oldest known animal genus.
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Class Articulata
Picture(s)
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Physical Description
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Articulate brachiopods have two valves that are different size. The larger shell is called the pedicle valve - contains a hole through which a fleshy stalk called a pedicle attaches to a substrate (rocks or sediment on the sea floor). The pedicle acts as an anchor that firmly holds the brachiopod in place. Brachiopods are immobile throughout adult life. The pedicle valve contains projections called teeth, which fit into sockets on the opposite brachial valve.
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Fossil Range
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Cambrian to recent. They flourished during Paleozoic (570-240 mya) and Mesozoic (240-65 mya) eras.
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Mode of Life or Habitat
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Most live in moderately deep water. They are sessile benthic suspension feeders.
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Additional Information
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They make up 95% of known brachiopod genera
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Genus Atrypa
Picture(s)
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Physical Description
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Atrypa is a genus of brachiopod with shells round to short egg-shaped, covered with many fine radial ridges, that split further out. Shells are usually around 1cm in length.
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Taxonomy
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Lower Silurian (more specifically Telychian) to Upper Devonian (specifically Frasnian)
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Mode of Life or Habitat
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Habitat was shallow water and soft substrates.
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Distribution
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Atrypa can be found on every continent except Antarctica.
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Genus Composita
Picture(s)
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Common Names
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Composita is also called Athyris
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Physical Description
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1 in (25 mm) long and wide. Composita had a smooth shell with a more or less distinct fold and sulcus and a round opening for the pedicle on the pedicle valve. Given the smooth shell, it was perfectly suited to survive in turbulent environments. Its shell is made of calcite.
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Fossil Range
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Found from the Upper Devonian to the Permian - especially abundant in Permian deposits.
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Mode of Life or Habitat
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It was abundant in warm, shallow seas.
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Distribution
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It is widespread in North America.
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Additional Information
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They are often present in rock with much shell debris.
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This fossil will only be tested at the State and National levels.
Genus Juresania
Picture(s)
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Physical Description
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It was about 16 mm long and 22 mm wide. It had a round outline, a convex ventral, and was covered with numerous small spines. These small spines were found on both halves of the shell, and are the easiest way to identify Juresania. It had very fine costae.
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Fossil Range
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Carboniferous (Pennsylvanian) to Late Permian.
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Mode of Life or Habitat
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Juresania was a suspension feeder in a marine environment.
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Distribution
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Nebraska, Kansas, Oklahoma, Texas, Nevada
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Additional Information
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Juresania is common in Beattie limestone and mostly in limestone or shale.
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Genus Leptaena
Picture(s)
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Physical Description
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It is best identified by concentric wrinkling in the shell, which is finely striated. The ridges are used to stabilize it in soft substrates. It is fan shaped.
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Fossil Range
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Ordovician to Permian.
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Mode of Life or Habitat
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It adapted to living in sediment by lying flat, allowing sediment to gather on top of it. Marine environment.
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Distribution
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Widespread in North America, China, Norway and UK.
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Additional Information
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Commonly found in Wenlock limestone
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Genus Mucrospirifer
Picture(s)
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Common Names
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Butterfly Shells.
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Physical Description
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Shell was typically 2.5 cm, but could grow up to 4 cm. Mucrospirifer was strophic, meaning that it had a well defined hinge.
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Fossil Range
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Ordovician through Jurassic - mainly existed in the Devonian. They survived the Permian extinction.
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Mode of Life or Habitat
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Soft, muddy, marine sediments
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Adaptations Over Time
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They had a big, long shell for the large surface area to prevent sinking into the mud and would help separate in-flowing and out-flowing currents.
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Distribution
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Worldwide distribution.
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Additional Information
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"Mucrospirifer" means “sharply pointed spire-bearer”
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Genus Platystrophia
Picture(s)
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Physical Description
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3/4 in (19 mm) long, 1¼ in (32 mm) wide. Their shells were made out of calcite, and they lost their pedicles as they aged. Each valve of the shell is convex in profile, and the hinge line between the valves is wide. Surface markings on the shell include prominent angular ridges and intervening linear depressions.
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Fossil Range
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Middle Ordovician through Upper Silurian
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Mode of Life or Habitat
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They lived in quiet intertidal zones - shallow and deep marine.
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Distribution
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Worldwide
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Genus Rafinesquina
Picture(s)
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Common Names
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Nicknamed the "Cursed Brachiopod."
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Physical Description
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Rafinesquina was 22 mm long and 28 mm wide. Their valves were flat and thin. They are "D" shaped, have concave brachial valve, and a convex pedicle valve. They have fine costae.
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Fossil Range
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Middle/Upper Ordovician
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Adaptations Over Time
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Good index fossil for the Ordovician.
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Distribution
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Widespread in North America
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Additional Information
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Named to honor Professor Constantine Rafinesque
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Order Rhynchonellida
Picture(s)
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Physical Description
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They have small, distinctive shells made out of calcium phosphate, often with highly inflated valves.
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Fossil Range
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Middle Ordovician to Recent. In the Mesozoic, they were the most abundant brachiopod.
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Adaptations Over Time
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They were the first articulate brachiopod.
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Additional Information
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Rhynchonellida are a still living order of brachiopods that first began to appear in the Ordovician. They can be identified by their wedge shape, and large ridges. They are biconvex, and have changed little since their appearance in the Ordovician.
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Mollusks (Phylum Mollusca)
Picture(s)
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No pictures have been added as of yet.
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Class Bivalvia (clams, oysters, mussels)
Picture(s)
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No pictures have been added as of yet.
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Physical Description
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Bivalves are a still living class of mollusks that include oysters, clams, mussels, and scallops. Their shells are either made of aragonite or calcite. They are usually bilaterally symmetrical. They may look superficially like brachiopods.
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Fossil Range
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Early Cambrian - Recent. The first freshwater bivalves appeared in the Devonian.
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Mode of Life or Habitat
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Mostly marine - some live in lakes and streams. Many bivalves burrow into the sediment. Bivalves can be shallow infaunal, deep infaunal, or epifaunal.
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Additional Information
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"Bivalvia" means "two valves."
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Genus Exogyra
Picture(s)
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Physical Description
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About 4 inches long and wide. The left valve is deep while the right valve is flat - they are asymmetrical. Their shells are very durable and made of aragonite.
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Fossil Range
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Jurassic to Cretaceous.
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Mode of Life or Habitat
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Solid substrates in warm seas. They were sessile filter feeders.
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Distribution
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Worldwide
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Additional Information
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Many of them survived as fossils due to the thick shells which were not easily destroyed.
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Genus Gryphaea
Picture(s)
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Physical Description
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They have heavy shells made of calcite. They have a cupped left valve and a flatter right valve, similar to exogyra. As adults, the curvature of the shell could become so pronounced the shell would not be able to open.
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Fossil Range
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Upper Triassic - Eocene.
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Mode of Life or Habitat
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They lived on muddy sea beds, cemented to a small particle of rock. They were infaunal suspension feeders.
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Distribution
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Worldwide (rare in North America but abundant in Europe)
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Additional Information
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They are also known as the "Devil's toe nails" because of their shape (the larger valve is called "the toenail").
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Genus Pecten
Picture(s)
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Common Names
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Scallop or seawater clam.
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Physical Description
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They are usually more than 85 mm wide. Has flat shells and distinct flat extensions to the hinge line called “wings.”
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Fossil Range
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Cretaceous to Quaternary - some say that they are still living.
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Mode of Life or Habitat
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They are able to swim - they do this by clamping together their two lightweight valves and forcing water out of the hinge. They are filter feeders and their diet consists mainly of plankton. They live in clean sand in moderately shallow waters where they rest on the bed in self-made depressions.
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Distribution
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Worldwide.
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Additional Information
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The name pectin comes from the latin word for comb or rake, and the genus was used for the basis of the Shell Oil Company's logo.
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Genus Glycymeris
Picture(s)
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Common Names
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Bittersweet Clam
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Physical Description
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They have medium-sized thick aragonite shells which are almost circular. The surface is either smooth or radially ribbed. The hinge is heavy, with a row of 6-12 teeth.
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Fossil Range
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Early Cretaceous to recent. They reached maximum diversity in the Cretaceous.
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Mode of Life or Habitat
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They burrow into the sand and mud in shallow waters.
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Adaptations Over Time
|
They evolved convergently with genus Composita.
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Distribution
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Worldwide. Today, they are common in North Carolina.
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Additional Information
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This genus was named by Carl Linnaeus in 1758.
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Genus Pholadomya
Picture(s)
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Additional Information
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Pholadomya is an extinct genus of marine clam that occurred from the early Triassic, to the late Pliocene. It is not on the Official Fossil List in 2020/21.
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Genus Astarte
Picture(s)
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Physical Description
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1 to 3 inches. They had annual growth lines.
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Mode of Life or Habitat
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Marine - mainly temperate, shallow water. They were benthic suspension feeders.
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Distribution
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Worldwide, mainly Northern Hemisphere.
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Additional Information
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Named after the goddess Astarte, a goddess of war and sexual love in the modern Middle East.
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Genus Nucula
Picture(s)
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Physical Description
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Shells grew up to 30 mm. They were approximately triangular in shape. The surface had fine cocentric growth lines.
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Fossil Range
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Ordovician - recent.
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Mode of Life or Habitat
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Shallow seas in the muddy sand close to the sediment surface. They are benthic selective deposit feeders, feeding on a variety of microzooplankton, organic matter, and microbes.
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Distribution
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Worldwide.
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Additional Information
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"Nucula" comes from Latin.
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Class Cephalopoda
Picture(s)
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No pictures have been added as of yet.
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Order Goniatitida (goniatites)
This fossil will only be tested at the State and National levels.
Picture(s)
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Order Ceratitida (ceratites)
This fossil will only be tested at the State and National levels.
Picture(s)
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Order Ammonitida (ammonites)
Picture(s)
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Additional Information
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Ammonoids have distinctive suture patterns which fall under three major categories:
- Goniatitic: These sutures have a zig-zag appearance and are characteristic of Paleozoic ammonoids
- Ceratitic: These sutures are characterized by lobes and saw-tooth patterns and are characteristic of early Mesozoic ammonoids
- Ammonitic: These sutures have much more frequent and divided lobes than Ceratitic sutures and they do not have saw-tooth patterns. They are characteristic of late Mesozoic ammonoids
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Genus Baculites
Picture(s)
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Physical Description
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It was anywhere from 7 cm from 2 meters in length. Males were smaller than females and had lighter ribbing. They had many chambers which would fill with air to increase buoyancy.
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Fossil Range
|
Upper Cretceous
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Mode of Life or Habitat
|
It was carnivorous and lived in the middle of the water column. There is much debate over whether they lived upright with tentacles on sea bed for foraging for food, or if they lived horizontally and near the surface of the water.
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Distribution
|
Widespread in North America
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Additional Information
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It's name means "walking stick rock." It is used as an index fossil.
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Genus Dactylioceras
Picture(s)
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Physical Description
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They were about 2.5 inches. They have a strong shell with ribs that are slightly inclined forward and closely spaced.
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Fossil Range
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Lower Jurassic
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Mode of Life or Habitat
|
They were slow swimmers, and probably scavenged on the sea floor. They spawned in clusters, and may have often died shortly after spawning.
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Distribution
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Worldwide - the best specimens are found in England and Germany. Many specimens are found in the Mazon Creek lagerstatten.
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Additional Information
|
Dactylioceras is a valuable index fossil. Their name (dactyl) means "finger" in Greek, referring to the ribs on the shell.
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Order Belemnitida (Belemnites)
Picture(s)
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No pictures have been added as of yet.
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Genus Belemnitella
Picture(s)
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Physical Description
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They are about 17cm long and 2cm wide. They had 10 arms which had inward-curving hooks used for grasping prey. They had a hard internal skeleton (rostrom/guard) which is long and narrow with a blunt apex. The phragomocone is the inner shell made of aragonite.
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Fossil Range
|
Upper Cretaceous
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Mode of Life or Habitat
|
They swam in shallow waters. They used their hooked tentacles to catch small prey. Their main predator was Ichthyosaurs.
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Distribution
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Northern Hemisphere
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Additional Information
|
Usually, only the rostrum, or guard, is fossilized. It is the state fossil of Delaware.
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Order Nautilida (Chambered Nautilus)
Picture(s)
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Order Orthocerida ("Orthoceras")
Picture(s)
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Additional Information
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Orthoceras was a cephalopod from the Lower Ordovician to the Upper Triassic, although the time of their extinction is not completely clear. The most likely fed on trilobites and small arthropods.
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Class Gastropoda (Snails)
Picture(s)
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No pictures have been added as of yet.
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Genus Conus
Picture(s)
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Additional Information
|
Conus is a gastropod that ranged from the Eocene to modern day. Conus most notably can fire a toxic harpoon containing various venoms known as conotoxins. They are the only gastropods known to kill humans.
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Genus Cypraea
Picture(s)
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Additional Information
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Cypraea, also known as a Cowrie, originated in the Miocene and still lives today. When non-threatened, it is soft. However, when a predator makes contact with it, it hardens its exterior and confuses the predator. They are about 2 cm long. They ate algae and corals. They are widespread throughout North America in distribution. It is sometimes used for jewelry and was used as currency by Africans and Chinese.
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Genus Platyceras
Picture(s)
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Additional Information
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Platyceras is a gastrophod ranging from the Silurian to the Middle Triassic. They fed off of crinoid excrement.
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Genus Turritella
Picture(s)
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Additional Information
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Turritella is a gastropod that originated in the Late Jurassic and still lives today. The name "Turritella" comes from the latin word turritus which means turreted or towered.
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Genus Worthenia
Picture(s)
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Additional Information
|
Worthenia was a gastropod that lived from the Devonian to the Triassic. It was named after the paleontologist Amos Henry Worthen.
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Echinoderms (Phylum Echinodermata)
Picture(s)
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No pictures have been added as of yet.
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Class Asteroidea (Starfish)
This fossil will only be tested at the State and National levels.
Picture(s)
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No pictures have been added as of yet.
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Class Blastoidea
Picture(s)
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No pictures have been added as of yet.
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Genus Pentremites
Picture(s)
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No pictures have been added as of yet.
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Class Crinoidea
Picture(s)
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No pictures have been added as of yet.
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Additional Information
|
Competitors are required to identify the stems, columns and calyxes of crinoids for this event.
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Class Echinoidea
Picture(s)
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No pictures have been added as of yet.
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Additional Information
|
Competitors are required to identify both regular and irregular echinoids, such as sea urchins and sand dollars.
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Class Ophiuroidea (brittle stars)
This fossil will only be tested at the State and National levels.
Picture(s)
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No pictures have been added as of yet.
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