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Fossilladyhttps://fossillady.wordpress.comThis is where I combine my photography and writing to share my fascination with fossils, beach stones, seashells and corals.

Brachiopods and Their Fossils Are Significant

September 7, 2010 by Fossillady

No other organisms typify the Age of Invertebrates more than brachiopods. They are the most abundant Paleozoic fossils ever found, except for maybe trilobites. Paleontologists use them to date rocks and other fossils along the same rock strata. Countless billions accumulated on the ocean floor with over 30,000 forms. Today, there are far fewer species, only about 300 species which live mostly in cold, deep ocean environments.

Brachiopod Fossilized Mold Cast found along Lake Michigan Shoreline

The brachiopod fossil specimens shown above and below are casts of the animal’s former shells which has filled in with sediment after the creature died and later the sediment turned to stone leaving an impression of the shell. The original shells very possibly broke up into pieces and washed away settling onto the seafloor along with multitudes of other brachiopod and clam shells which ultimately develop into limestone.

Fossilized Brachiopod Mold Cast

How They Lived – Thick shelled forms of brachiopods are ribbed and live in shallow water. Thin shelled forms are smooth and live in deep water. Some brachiopods grow to 9 inches across, but most are about an inch in diameter. They live in communities attached to objects by a muscular foot called a pedicle. They strain water in and out of their shells filtering microorganisms with their lophophores, a crown of tentacles.

Sample of stone found on Lake Michigan beach embedded with broken shell pieces

Brachiopods were the first of their kind to lose mobility and develop a hard covering. They look like clams but are very different inside. To tell them apart, clams (pelecypods) have uneven shaped left and right shell valves, but the tops and bottoms are identical. Brachiopods have evenly shaped (symmetrical) left to right valves, but the bottom valve is smaller.

CLASSIFICATION

Common Name: Brachiopod or Lamp Shell (named for resemblance to ancient Roman oil lamps)

Kingdom: Animalia

Phylum: Brachiopoda (means arm and foot)

Class: Articulated (shells clamp together by a hinge)

Inarticulated (shells clamp together by a muscle)

Genus: Brown Sample possibly Pseudoatrypa sp Grey Sample possibly Atrypa, reticularis

Brachiopods in the Ocean Mist

Check out my two fiction books blended with prehistory insights and imaginative storytelling that entertain as they educate. Geare toward young exlporers interested in early life and fossils, or young readers who simply like a good story; ages 11-15+. Also available, a coloring/activity book featuring scenes from the books along with many of the plants and animals that lived during the amazing Devonian Time Period; fossil photos and descriptions included. Available on Amazon.com

Sea Lily Crinoid Fossils

September 3, 2010 by Fossillady

Crinoid “Sea Lily” Fossil Pieces

Beachcombers with a keen eye become obsssessed trying to find these tiny crinoid fossil pieces shaped like cheerios mixed among the beach stone rubble and sand along the shores of Lake Michigan. If they are lucky, they will find a piece or two everytime, hence the common name “Lucky Stones“. The largest crinoid fossil in the photo above is just under the size of a dime so you can imagine the luck and patience required to find them.

These extinct fossil species are also referred to as “Sea Lilies“ explained by their colorful flower-like appearance as living creatures. They were a type of ocean invertebrate animal that possessed long branching arms and a midsection that sat atop of a single slender stem, sometimes reaching two meters above the seafloor. Feathery tentacles at the tips of their branching arms trapped tiny food particles floating by in the ocean currents.

Crinoid Sea Lily Fossil

Crinoids were sessile creatures, meaning they attached themselves directly to the seafloor or to underwater rocks or sunken wood. A spawning of their offspring from these bottom bound creatures may have resembled the spring releasing of thousands of dandelion seeds blowing by in a gust of wind.

Crinoid Broken Stem Fossils

Crinoid skeleton fossils are usually found broken up into individual “cheerio” shaped sections or partial stems. Each circular section was stacked one on top of another forming the entire animal framework. The Native Americans used the fragmented fossilized sections for stringing necklaces. Consequently, yet another fitting common name for them is “Indian Beads“.

Embedded Crinoid Pieces found on Oval Beach, Lake Michigan

Crinoid’s amazing history dates back as early as the Ordovician Period around 500 million-years-ago, but their heyday happened during the Mississippian Period around 345 mya. Their fossil remains are found widespread in North America explained by the fact that much of the continent was covered under warm shallow seas. The sea lily crinoids were a dominant feature in the Paleozoic Era seas, but most varieties succumbed to the great Permian extinction around 252 mya. Today, a few species survive in cold deep-water environments, but dwarf in length compared to the prehistoric varieties.

Crinoid Classification

Kingdom: Animalia
Phylum: Echinoderm (means spiny skin, i.e. starfish, sea urchins, feather stars, crinoids)
Class: Crinoid (means flower form)

Sea Lily Crinoids Drawing in the Ancient Seas

What We Can Learn From Oysters

September 3, 2010 by Fossillady

Exogyra ponderosa Oyster Fossil (Cretaceous Period 65 to 100 million-years-ago)

A lesson we can learn from oysters is that even though they have no heart to feel and no brain to reason, many of their species build massive reef communities which provide protection for one another; and not only for their own kind, but for many other ocean organisms. Very fittingly, they’ve been referred to as the “unshellfish”.

Exogyra is a large extinct oyster species that lived in the soft sediment of ancient shallow marine waters. It possessed a thick shell with a distinct pattern of ribbing and pitting representing growth lines. Many of its kind thrived during the Upper Cretaceous Period around 65 to 100 million years ago. Their shells opened using a strong abductor muscle to expose a foot which pushed it along and a siphon to filter food and take in oxygen from the ocean water. The abductor muscle scars on the valves are observable in the photo below.

Exogrya ponderosa Oyster Fossil Upper and Lower Valves

Oysters and Love

In Greek mythology, the Greek Goddess of Love “Aphrodite” was said to have sprang up out of the ocean on an oyster shell. The term “Aphrodisiac”, meaning to heighten love, has been related to oysters ever since. Also, the charismatic Casanova was known to have eaten twelve oysters a day, believing it would enrich his love life.

Exogyra ponderosa Oyster Fossil Underside with Upper and Lower Valves in Closed Position

The Exogyra in my collection is a beautiful specimen that is quite heavy from being fossilized into solid stone. In the two photos above of its underside, you can clearly see how the valves fit together and how the lower valve is much smaller and flatter than the convex upper valve.

CLASSIFICATION

Scientific Name: Exogyra, ponderosa

Common Name: Oyster

Phylum: Mollusk (Large group of marine and fresh water invertebrates having soft bodies enclosed in a shell.)

Class: Pelecypod or Bivalve (Means hinged shell)

Order: Ostreoida (Means true oyster with irregular shell and adductor muscle; pearl oysters are not true oysters.)

Family: Gryphaeidae (Includes honeycomb oyster or foam oyster characterized under magnification with distinct shell structure.)

Genus: Exogyra (Extinct group of large, shallow-marine oysters possessing thick shells with distinctive spiraled peaks and ribbing on upper valves; lower valves were smaller and flattened.)

Species: Ponderosa (From latin word meaning heavy, weighty or large)

Pycnodonte Oyster Fossil, Upper and Lower Valves (Cretaceous 135 Million-Years-Ago to Miocene 40mya)

Today, the small oyster fossils shown above and below are found in abundance within shell-banks along North American coast lines. In their lifetime, they likely washed ashore during storms and were deposited on the beaches. Eventually, layers of sand and sediment buried them deep down cutting off oxygen and millions of year later, silica and other minerals permeated the shells and they fossilized.

Texigryphaea Oyster Fossil (Cretaceous 135 Million-Years-Ago to Miocene 40 mya)

Oysters For Food

Oysters have been a part of the human diet since Greek and Roman times. Today, two-billion pounds are eaten every year around the world. Oysters are prepared in a variety of ways, but raw on the half-shell is the most nutritious. Besides being an excellent source of protein, oysters contain rich sources of B vitamins, and scarce minerals such as calcium, iron, zinc, selenium and magnesium.

Graphea navia Oyster Fossil (Upper Triassic 210 Million-Years-Ago to Upper Jurassic 150 mya)

Hand Crafted Oyster Jewelry

Only one in 10,000 oysters produce a pearl, so human intervention has found a way to culture them artificially, but it still takes about six years for the oyster to complete the process. Many artists also craft beautiful jewelry using the shells of various oysters.

Exogyra, Graphea and Texigryphaea Extinct Oyster Fossil Rendering Drawing

Disclaimer: Room for error as I am 90% certain on the identities of the small oyster shells.

Lace Coral / Bryozoan

August 23, 2010 by Fossillady

Bryozoan (Lace Coral) Fossil found on Lake Michigan Beach

Combing the shores of Oval Beach in Saugatuck, Michigan, as well as many other beaches along the fresh water coastline, you will occasionally find these interesting fossil samples of one of Earth’s earliest multicellular creatures! They are often called lace corals because of their delicately threaded appearance, but they are not true corals; instead, they are moss-like animals better known as bryozoans.

Today, there are around 5000 species of bryozoans, living mainly in marine water environments. Another 15,000 species or more are known from the fossil records dating as far back as 500 million-years-ago and some of their descendants are still living today. During the Mississippian Period (359.2 mya – 318.1 mya) bryozoans were so plentiful that their broken calcium-carbonate skeletons formed entire limestone beds.

Lace Coral, Bryozoan, Fenestella Source

Bryozoan Colony Growth

Bryozoans form tight colonies sculpted by hard, limy, branching structures, although, freshwater species, form gelatinous blobs. A bryozoan colony often encrusts surfaces such as rocks, shells or even kelp. A colony consists of thousands of individual animals called “zooids”. Each individual zooid lives inside its own limy tube called a zooecium. The zooecium is the size of a sewing needle. A single zooid begins the colony. Each additional zooid is a clone of the very first one. A bryozoan colony has been observed growing from a single zooid to 38,000 in just five months.

Bryozoan (Lace Coral) Fossil, found on Lake Michigan Beach

Interesting How Bryozoan Feed

In order to feed, each bryozoan zooid has an opening through which the animal can extend its ring of tentacles called a lophophore. The bryozoan captures microscopic animals from the water as they pass by its lophophore tentacles. If one zooid receives food, it nourishes the neighboring zooids because they are joined by strands of protoplasm. If only people could be more like them, feeding the masses; imagine!

Bryozoan CLASSIFICATION

Common Name: “Lace Coral”
Scientific Name: “Fenestella, plebeian”
Kingdom: Animalia
Phylum: Bryozoa (means moss animal)
Class: Stenolaemata (means tubular walls)
Order: Fenestrata (lacy, net-like, or fan-shaped colonies)
Family: Fenestellida (group of fan shaped or mesh-like bryozoans)
Genus: Fenestella (rigid, upright branches connected by narrow crossbars creating a delicate, mesh-like, or “lace-like” pattern).
Species: plebeian

Interesting Horn Corals

August 21, 2010 by Fossillady

Horn Coral Fossils (Grewingkia, canadensis)

The horn corals have been extinct for millions of years, but in their heyday they must have added an extraordinary beauty to the diorama of the Paleozoic seafloor. Some varieties dominated the underwater, prehistoric scene reaching multiple-meters in height off the seafloor. At night, the coral animal flung out its long tentacles in order to sweep up unsuspecting tiny organisms passing by in the ocean currents.

Two horn coral fossils featured:

Grewingkia canadensis horn coral lived primarily during the Ordovician period approximately 485-443 million years ago. The largest could reach up to 5 inches long. They are the most common species found in North American deposits, particularly in the Cincinnati Arch region of Kentucky, Indiana, and Ohio.
Heliophyllum halli, horn coral lived primarily during the Devonian period 419–359 Mya. The largest could reach up to 6 inches long. They are commonly found in North America (especially New York) but also in South America (Colombia).

Horn Coral Fossil (Heliophyllum, halli)

Horn Corals (rugose order of corals, meaning wrinkled wall) were famously known as solitary corals with a few colony variety exceptions. Horn Corals attached themselves to the seafloor with the narrow ends of their exoskeletons. As the organism grew, their upper body widened where the tentacles were encased; hence the reference to the shape of a horn. Horn corals flourished during the Paleozoic time slot from about the Mid-Ordovician Period around 250 million years ago throught to the end of the great Permian mass extinction about 250 million years ago.

Two Horn Coral Species Classification

Paleozoic Horn Corals in the Ocean Mist Drawing

Horn Coral Internal Structure

As a general rule, rugose coral have stronger radial septa (septum) or vertical growth walls that radiate outward from the center . Rugose corals differ from other corals due to the pattern by which they add septa (like bicycle spokes) throughout their growth spurts. Named for their wrinkly outer skin, they possessed less developed horizontal partitions, but stronger vertical partitions.

Pecopteris Leaf of Fern Tree “Psaronius”

August 17, 2010 by Fossillady

The extinct fern leaves called Pecopteris grew on the tree called Psaronius appearing in the coal swamps of the Carboniferous and Permian time periods, approximately 359-251 million years ago. Pecopteris leaves grew and dropped off the medium sized, 35 foot (10 meters) Psaronius tree, one of the most common Carboniferous varieties. With its expansive leaves and branches, it resembled modern day palm trees. Impressively, it produced as many as 7000 tiny spores on the underside of its leaves. These fossil samples are preserved in gray coal shale unearthed in the state of Pennsylvania as with many Carboniferous leaf fossils.

Pecopteris Leaf Fossil Imprint from Carboniferous Period Psaronius Fern Tree

Description of Pecopteris Leaves– The individual leaflets of Pecopteris compound fern leaves are oval, straight and narrow. The midveins of each extends all the way up to the tip. A good way to identify Pecopteris leaves is hinted in its name, derived from the Greek word meaning, to comb. Observably, the leaflets along the leaf stems feature an arrangement resembling that of a comb.

Devonian to Carboniferous to Permian Era Pecopteris Imprint Fossil Leaflets from Fern Tree

What makes ancient fern trees so special? The large fronds produced by Pecopteris leaves, which grew upon the ancient Psaronius fern trees, cloaked the forest floor in deep shade together with the Medullosa seed-fern trees and others. Consequently, they protected the ancient creatures below from the strong ultra violet rays of the sun as it was closer to earth and more powerful during the Paleozoic Era. Also, the shedding and decomposing of leaves created more layers of soil for roots to extend deeper and deeper, alleviating the need for trees to grow near water pools. Trees were then able to spread further inland. Yet another benefit was that the leaves fed inland water sources cultivating more fresh water fish varieties. But this fantastic fossil fern is most special to me because I inherited from my late father-in-law, Joseph Mirto II. It was found in Johnstown, Pennsylvania.

PECOPTERIS LEAF CLASSIFICATION

Kingdom: Plantae

Division: Pteridophtya (meaning vascular plant with transport system for nutrients and fluids)

Class: Filicopsida (Ferns which reproduce with spores)

Order: Marattiales (primitive ferns)

Family: Marattiaceae (known for having the largest fronds and spores of any fern, alongside thick, starchy, edible rhizomes)

Genus: Pecopteris (known for comb-like arranged leaflets)

Psaronius Fern Tree Rendition Drawing, Devonian to Carboniferous to Permian Era

PSARNONIUS FERN TREE CLASSIFICATION

Botanical Name: Psaronius Common Name: Fern Tree

Kingdom: Plantae

Division: Tracheophyta (meaning vascular plant with transport system for nutrients and fluids)

Class: Marattiopsida (distinguished by massive roots and largest fronds of all seed fern trees)

Order: Marattiales (primitive ferns)

Family: Psaronlaceae (small, brownish-orange,or black dots found on the underside of mature fern fronds)

Genus: Psaronius (dominant genus lacking true wood)

Species: magnificus (especially large fronds)

Lepidodendron & Sigillaria Scale Trees

August 14, 2010 by Fossillady

Lepidodendron “Lycopod” Scale Tree Trunk Fossil, Devonian to Carboniferous Era

The fossil above is a section from a large sized, 100 foot (30 meter) lycopod or scale tree trunk which originated around 380 million years ago during the late Devonian Period. The various lycopod trees reached their zenith during the era of coal swamp forests from the Carboniferous Period about 355 to 300 million years ago.

The fossil is very dense and heavy of petrified wood. Petrified wood materializes when plant matter is buried by sediment and protected from decay caused by oxygen and organisms. Subsequently, groundwater rich in dissolved solids flows through the tree sediments, replacing the original plant material with silica, calcite, pyrite, iron or another inorganic material such as opal.

Sigillaria & Lepidodendron Tree Leaf Fossils, Devonian to Carboniferous Era

The above fossil shows leaf imprints grown on giant lycopod trees such as Sigillaria and Lepidodendron, cast in coal shale. The trunks of lycopod scale trees were topped with plumes of long thin, grass-like leaves which were often arranged like that of a bottle brush. The trees had relatively short life-cycles growing rapidly reaching heights sometimes up to 130 feet (40 meters). The trunks most distinguishing feature displays patterns of deep grooves, the result of leaf scars along the trunk’s surface. The tree trunks actually would have appeared hairy-like, at least as they grew.

Lycopod forests of plenty generated tremendous amounts of decaying peat. After millions of years, it became coal buried deep in the ground, later, fueling the Industrial Revolution. More importantly, their decaying matter helped revolutionize Earth’s emerging forests by creating soil for trees to develop deeper root systems. This enabled new tree varieties to spread further inland without relying solely on wet swampy habitats.

Devonian to Carboniferous Era Lepidodendron Lycopod Scale Tree Rendition Drawing

Devonian to Carboniferous Era Sigillaria Lycopod Scale Trees Rendition Drawing

LYCOPOD SCALE TREE CLASSIFICATIONS

Botanical Names: Sigillaria and Lepidodendron

Common Name: Scale Tree or Lycopod Tree

Kingdom: Plantae

Division: Lycopod-iophyta (oldest vascular plant group, reproduced by releasing spores)

Class: Isoetopsida (plants with hollow quill-like leaves spirally arranged on a single, unbranched vein) ie quillworts, scale trees, spike moss)

Order: Lepidondrales (primitive vascular tree-like plants related to lycopods which are loosely grouped with ferns)

Family: Lepidodencraceae (has arrangement of spores on cones born on the shoots)

Genera: Sigillaria (possess deep lace pattern on trunk with bottle brush crown of leaves)

Genera: Lepidodendron (possess deep diamond pattern on trunk with plume of grassy leaves on crown)

Amazing Ammonites

August 13, 2010 by Fossillady

Ammonite Fossil Inner Chambers

Ammonites are an extinct marine shelled mollusk animal belonging to the class of cephalopods related to today’s squids, octopus, cuttlefish and the nautilus. Ammonites moved in short spurts using a method of jet propulsion by siphoning the ocean water into the inner chambers of their shells and then pushing the water out powerfully through a tube structure called a siphuncle. These inner chambers held water and special gases which helped the animal descend deep down into the ocean depths and reversely, float upward to shallower depths by filling and releasing the gases and water in and out of the chambers.

Cretaceous Period Oceanic Environment (145-66 million years ago) Artist Rendition

The Douvilleiceras, mammilatum ammonite fossil shown below possessed well-defined growth patterns over its outer shell in the form of knobs or sutures. Douvilleiceras’ spiny knobs are thought to be an indicator of a hostile environment. It lived during the early Cretaceous Period (112–100mya) and was unearthed in Madagascar, Africa within the Albian Era Formation.

Ammonite Fossil (Douvilleiceras, mammilatum)

Ammonites lived during the Paleozoic and Mesozoic Eras, more specifically from the Devonian period around 419 million years ago reaching their zenith and also their extinction during the Cretaceous period around 66 million years ago along with the dinosaurs. They were descendants of their cousin straight-shelled nautiloids developing a coiled shells which allowed them more agility and maneuverability than their predecessors within the oeanic environments.

Mortoniceras sp Ammonite Fossil

The above fossil is a broken section of an ammonite’s shell belonging to the genus, Mortoniceras sp. It was unearthed in the state of Arkansas in a dried up riverbed within the limestone Goodland Formation. The shell is characterized by deep keels and ribbing. It lived mainly during the Cretaceous Period (145 to 66 mya). As with all the ammonites, its fate was doomed side by side with the dinosaurs.

Mortoniceras Ammonite Fossil (Top View)

The siphuncle tube was also used to regulate buoyancy by controlling the amount of gas and water in the animal’s inner chambers. It lay along the outer rim of the ammonite’s shell.

Multi-purpose Tentacles

The ammonites were ocean predators grabbing their victims with precision and crushing them with their long, powerful tentacles. These tentacles contributed to another important function. They contained special sensors which facilitated their ability to navigate and locate prey in the vastness of the ocean.

Mortoniceras Ammonite Fossil

Above photo shows a complete sample of Mortoniceras sp from the state of Texas, Fort Worth Formation, Tarrant County

Ammonites possessed large heads and are assumed to have been highly intelligent much like their modern day cousins including octopuses, squids, cuttlefish and the nautilus. Scientist debate whether ammonites contained ink sacs for defense.

Ammonite Drawing

CLASSIFICATION

Phylum: Mollusk (large diverse group of invertebrates possessing a shell, i.e. clams, snails, oysters, etc.)
Order: Ammonitida (characterized by thick, ribbed patterned shells)
Class: Cephalopod (means prominent head and tentacles, i.e. octopuses, cuttlefish, squids, nautilus)
Family: Brancoceratidae
Genus: Mortoniceras (characterized by deep keels, tubercules (knobs) and ribbing)

For additional ammonite photos, species and interesting facts, scroll to the bottom of this article when searching under the “Categories” section “Ammonite Fossils” otherwise, click HERE.

Check out my two fiction books blended with prehistory insights and imaginative storytelling that entertain as they educate. Geared toward young exlporers interested in early life and fossils, or young readers who simply like a good story; ages 11-15+. Also available, a coloring/activity book featuring scenes from the books along with many of the plants and animals that lived during the amazing Devonian Time Period; fossil photos and descriptions included. Available on Amazon.com

Manuiceras sp and Cleoniceras sp Ammonite Fossil Identification and Interesting Facts

August 12, 2010 by Fossillady

Ammonite Fossil

Manuicera sp. lived in the ancient seas when the dinosaurs walked the earth. In general, the ammonite’s abundance peaked during the Cretaceous Period between 145 to 66 million-years-ago. But according to the fossil records, their incredible long history began as early as 440 mya during the Silurian Period.

This Manuicera sp ammonite fossil was unearthed from a dried up riverbed in the state of Arkansas; they have also been unearthed in the state of Texas. Both of these U.S. states lie within the limestone Goodland Formation where many other Cretaceous fossils have been discovered. Originally, I mistakenly identified the fossil as, Dufrenoy justinae, but that was when I was newer to the field with a less discerning eye and research skills. So there you go.

A variety of ammonite forms, from Ernst Haeckel‘s 1904 Kunstformen der Natur (Art Forms of Nature)

The amazing illustration above shows how ammonites vary greatly in the ornamentation (surface relief) of their shells. Some may be smooth and relatively featureless, except for growth lines. In others, various patterns of spiral ridges and ribs or even spines are shown.

Numerous ammonite fossils have been unearthed boasting a worldwide distribution which indicates the theory of continental drift. Due to their abundance of an estimated 10,000 species, scientists use them as date markers for other fossils along the same rock layers.

Ammonites grew from a few inches in diameter to the size of truck tires.

Manuiceras Ammonite Drawing

Manuiceras CLASSIFICATION

Phylum: Mollusk (soft body of invertebrate animal encased in shell)
Class: Cephalopod (means prominent head and tentacles, i.e. octopus, squid, cuttlefish, nautilus)
Order: Ammonitida (characterized by thick ribbed and patterned shells)
Family: Acanthoceratidae (known for their thick, ribbed shells, which were common during the Cretaceous period).
Genus: Manuiceras

Cleoniceras. Ammonite Fossil

Cleoniceras sp ammonite fossil is approximately 110 million years old from the early Cretacous Period unearthed in Mahajanga Province of Madagascar, Africa. It is characterized by spiraled, high-whorled, tightly coiled shells with distinct wavey ribs. These marine cephalopods are often found polished, revealing iridescent internal chambers filled with calcite or aragonite.

For additional information about these incredible marine animals, see my other article Amazing Ammonites .

Interesting Facts About Trilobites

August 12, 2010 by Fossillady

Calymene, celebra Trilobite Fossil

This Calymene, celebra trilobite was a scavenger finding food on the ocean floor where it could easily burrow underneath the sand to hide from predators. Many of their fossils are often found rolled up in a defensive position. They were able to bend tightly due to their chiton exoskeletons fitted with overlapping sections. Think of roly-poly bugs, or pillbugs. Calymene celebra possessed smaller eyes than many other trilobite species.

Trilobites have the distinction of possessing a segmented body, multiple jointed limbs and an armored outer shell, placing them in the category of “arthropods” related to insects and crustaceans. Trilobite means three lobes in Greek, from “tri” and “lobos”, named for their three major lengthwise body sections.

Most trilobites grew to only about 3 inches (7.6 cm) long, while a few species reached almost 3 feet (1 meter) long!

Trilobites developed several different life styles; some moved over the seabed as predators or scavengers, while others were filter feeders, yet some swam along various ocean stratas feeding on plankton. Most were sluggish swimmers, while some later varieties were designed precisely for speed and swam in the mid-ocean, pelagic zones where more predators existed.

Calymene, celebra Trilobite Fossil

This little Calymene trilobite crawled on the ocean floor around 400-440 million years ago during the Silurian to Devonian time periods, living up to 10 years. A good number of their fossils are found in Michigan and other Midwest states. During the Devonian period, Michigan and other Midwest States were situated near the equator submerged under warm shallow seas, which provided a perfect, nutrient-rich environment for trilobites to thrive in large numbers. The Calymene, celebra is Wisconsin’s official state fossil.

Trilobites existed and dominated the oceans for an amazing 270-300 million years beginning from the early Cambrian period, approximately 521 million years ago, to the end of the Permian period mass extinction, approximately 250 million years ago, which wiped out over 90% of all species living on Earth at the time.

Calymene celebra Trilobite Drawing

Calymene Trilobite Classification

Phylum: Arthropoda (Invertebrate animals with jointed legs, segmented bodies, exoskeletons made up of chiton, a tough fibrous material often mineralized with calcium carbonate)
Class: Trilobota (Means three lobes or body sections. They are one of the earliest and most successful groups of artrhopods to appear in the fossil record with an estimated 22,000 species)
Order: Phacopida (Means lens face, these trilobites lived from the late Cambrian Period to the late Devonian Time Period)
Family: Calymenidae (Distinct, rounded shape of their head shield)
Genus: Calymene (Small group of trilobites often found rolled up)
Species: celebra

Check out my fiction books featuring factual prehistory insights blended with imaginative storytelling that entertain as they educate. Perfect for young explorers ages 11-15+ or young readers who simply like a good story, available on Amazon.com. Also available, a coloring/activity book featuring scenes from both books along with many of the plants and animals that lived during the amazing Devonian Time Period; fossil photos and descriptions included.