Sea Urchin - Stomechinus Multigranularis
Middle Jurassic - 156mya
Boulemane Region, Morocco
ITEM# INVERT-Morocco-0009
This is an excellent example of the sea urchin Stomechinus Multigranularis from the Middle Jurassic of Morocco. Stomechinus Multigranularis is a member of the Order Echinoida, Family Echinothuriidae.
Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal, but is easily visible in the dried test.
Like other echinoderms, sea urchin early larvae have bilateral symmetry, but they develop five-fold symmetry as they mature. This is most apparent in the "regular" sea urchins, which have roughly spherical bodies with five equally sized parts radiating out from their central axes. Several sea urchins, however, including the sand dollars, are oval in shape, with distinct front and rear ends, giving them a degree of bilateral symmetry. In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet. This "irregular" body form has evolved to allow the animals to burrow through sand or other soft materials.
Sea urchins' tube feet arise from the five ambulacral grooves. Tube feet are moved by a water vascular system, which works through hydraulic pressure, allowing the sea urchin to pump water into and out of the tube feet, enabling it to move. Sea urchins feed mainly on algae, but can also feed on sea cucumbers and a wide range of invertebrates, such as mussels, polychaetes, sponges, brittle stars, and crinoids.
Boulemane Region, Morocco
ITEM# INVERT-Morocco-0009
This is an excellent example of the sea urchin Stomechinus Multigranularis from the Middle Jurassic of Morocco. Stomechinus Multigranularis is a member of the Order Echinoida, Family Echinothuriidae.
Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal, but is easily visible in the dried test.
Like other echinoderms, sea urchin early larvae have bilateral symmetry, but they develop five-fold symmetry as they mature. This is most apparent in the "regular" sea urchins, which have roughly spherical bodies with five equally sized parts radiating out from their central axes. Several sea urchins, however, including the sand dollars, are oval in shape, with distinct front and rear ends, giving them a degree of bilateral symmetry. In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet. This "irregular" body form has evolved to allow the animals to burrow through sand or other soft materials.
Sea urchins' tube feet arise from the five ambulacral grooves. Tube feet are moved by a water vascular system, which works through hydraulic pressure, allowing the sea urchin to pump water into and out of the tube feet, enabling it to move. Sea urchins feed mainly on algae, but can also feed on sea cucumbers and a wide range of invertebrates, such as mussels, polychaetes, sponges, brittle stars, and crinoids.
Sea urchins are some of the favorite foods of sea otters and California sheephead, and are also the main source of nutrition for wolf eels. Left unchecked, urchins devastate their environments, creating what biologistas call an urchin barren, devoid of macroalgae and associated fauna. Sea otters that have recolonized these areas have dramatically improved coastal ecosystem health and biodiversity.
The earliest echinoid fossils date to the upper part of the Ordovician period, and the taxon has survived to the present day as a very successful and diverse group of invertebrates. In well-preserved specimens, spines may be present, but usually on the test remains.
This very large example measures approximately 2.5 inches in diameter and 1.5 inches tall.
This very large example measures approximately 2.5 inches in diameter and 1.5 inches tall.
$
50.00
Echinoid - Asterocidaris bistriata
Lower Jurassic
Amellago, Morocco
ITEM# INVERT-Morocco-0008
This is a museum-quality example of the sea urchin Asterocidaris bistriata from the Lower Jurassic of Morocco. Asterocidaris bistriata is a member of the Order Hemicidaroida, Family Hemicidaridae.
The earliest echinoid fossils date to the upper part of the Ordovician period (circa 450 mya), and the taxon has survived to the present as a successful and diverse group of organisms. Spines may be present in well-preserved specimens, but usually only the test remains. Isolated spines are common as fossils. Some echinoids (such as Tylocidaris clavigera, from the Cretaceous period's English Chalk Formation) had very heavy, club-shaped spines that would be difficult for an attacking predator to break through and make the echinoid awkward to handle. Such spines simplify walking on the soft sea floor.
Most of the fossil echinoids from the Paleozoic era are incomplete, consisting of isolated spines and small clusters of scattered plates from crushed individuals, mostly in Devonian and Carboniferous rocks. The shallow-water limestones from the Ordovician and Silurian periods of Estonia are famous for echinoids. Paleozoic echinoids probably inhabited relatively quiet waters. Because of their thin tests, they would certainly not have survived in the wave-battered coastal waters inhabited by many modern echinoids. During the upper part of the Carboniferous period, a marked decline in echinoid diversity occurred, and this trend continued to the Permian period. They neared extinction at the end of the Paleozoic era, with just six species known from the Permian period. Only two lineages survived this period's massive extinction and into the Triassic: the genus Miocidaris, which gave rise to modern cidaroida (pencil urchins), and the ancestor that gave rise to the euechinoids. By the upper part of the Triassic period, their numbers began to increase again. Cidaroids have changed very little since the Late Triassic and are today considered to be living fossils.
The euechinoids, though, diversified into new lineages throughout the Jurassic and into the Cretaceous periods, and from them emerged the first irregular echinoids (superorder Atelostomata) during the early Jurassic, and later the other superorder (Gnathostomata) of irregular urchins, which evolved independently. These superorders today represent 47% of all extant species of echinoids because of their adaptive breakthroughs, which allowed them to exploit habitats and food sources unavailable to regular echinoids. During the Mesovoic and Cenozoic eras, the echinoids flourished. Most echinoid fossils are often abundant in the restricted localities and formations where they occur. An example of this is Enallaster, which exists by the thousands in certain outcrops of limestone from the Cretaceous period in Texas. Many fossils of the Late Jurassic Plesiocidaris still have the spines attached.
Some echinoids, such as Micraster, which is found in the Cretaceous period Chalk Formation of England and France, serve as zone orindex fossils. Because they evolved rapidly, they aid geologists in dating the surrounding rocks. However, most echinoids are not abundant enough and are of too limited range to serve as zone fossils.
In the Paleogene and Neogene periods (circa 66 to 1.8 Mya), sand dollars (order Clypeasteroida) arose. Their distinctive, flattened tests and tiny spines were adapted to life on or under loose sand. They form the newest branch on the echinoid tree.
This beautiful specimen is approximately 3 3/4 inches in diameter on a matrix measuring 5 1/4 inches by 4 5/8 inches.
Amellago, Morocco
ITEM# INVERT-Morocco-0008
This is a museum-quality example of the sea urchin Asterocidaris bistriata from the Lower Jurassic of Morocco. Asterocidaris bistriata is a member of the Order Hemicidaroida, Family Hemicidaridae.
The earliest echinoid fossils date to the upper part of the Ordovician period (circa 450 mya), and the taxon has survived to the present as a successful and diverse group of organisms. Spines may be present in well-preserved specimens, but usually only the test remains. Isolated spines are common as fossils. Some echinoids (such as Tylocidaris clavigera, from the Cretaceous period's English Chalk Formation) had very heavy, club-shaped spines that would be difficult for an attacking predator to break through and make the echinoid awkward to handle. Such spines simplify walking on the soft sea floor.
Most of the fossil echinoids from the Paleozoic era are incomplete, consisting of isolated spines and small clusters of scattered plates from crushed individuals, mostly in Devonian and Carboniferous rocks. The shallow-water limestones from the Ordovician and Silurian periods of Estonia are famous for echinoids. Paleozoic echinoids probably inhabited relatively quiet waters. Because of their thin tests, they would certainly not have survived in the wave-battered coastal waters inhabited by many modern echinoids. During the upper part of the Carboniferous period, a marked decline in echinoid diversity occurred, and this trend continued to the Permian period. They neared extinction at the end of the Paleozoic era, with just six species known from the Permian period. Only two lineages survived this period's massive extinction and into the Triassic: the genus Miocidaris, which gave rise to modern cidaroida (pencil urchins), and the ancestor that gave rise to the euechinoids. By the upper part of the Triassic period, their numbers began to increase again. Cidaroids have changed very little since the Late Triassic and are today considered to be living fossils.
The euechinoids, though, diversified into new lineages throughout the Jurassic and into the Cretaceous periods, and from them emerged the first irregular echinoids (superorder Atelostomata) during the early Jurassic, and later the other superorder (Gnathostomata) of irregular urchins, which evolved independently. These superorders today represent 47% of all extant species of echinoids because of their adaptive breakthroughs, which allowed them to exploit habitats and food sources unavailable to regular echinoids. During the Mesovoic and Cenozoic eras, the echinoids flourished. Most echinoid fossils are often abundant in the restricted localities and formations where they occur. An example of this is Enallaster, which exists by the thousands in certain outcrops of limestone from the Cretaceous period in Texas. Many fossils of the Late Jurassic Plesiocidaris still have the spines attached.
Some echinoids, such as Micraster, which is found in the Cretaceous period Chalk Formation of England and France, serve as zone orindex fossils. Because they evolved rapidly, they aid geologists in dating the surrounding rocks. However, most echinoids are not abundant enough and are of too limited range to serve as zone fossils.
In the Paleogene and Neogene periods (circa 66 to 1.8 Mya), sand dollars (order Clypeasteroida) arose. Their distinctive, flattened tests and tiny spines were adapted to life on or under loose sand. They form the newest branch on the echinoid tree.
This beautiful specimen is approximately 3 3/4 inches in diameter on a matrix measuring 5 1/4 inches by 4 5/8 inches.
$
300.00
Eocrinoid - Ascocystites sp.
Lower Ordovician
El Kaid Errami, Morocco
ITEM# INVERT-Morocco-0007
This is an excellent example of the eocrinoid Ascocystites sp. From the Lower Ordovician of Morocco. Ascocystites sp. is a member of the Order , Family Ascocystitidae.
The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian.
The eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera, Diploporita, Coronoidea, Blastoidea, Parablastoidea, and Paracrinoidea. The earliest genera had a short holdfast and irregularly structured plates. Later forms had a fully developed stalk with regular rows of plates. They were benthic suspension feeders, with five ambulacra on the upper surface, surrounding the mouth and extending into a number of narrow arms. An unusual Ordovician form was the conical Bolboporites with its single brachiole.
Eocrinoids are among the earliest groups of echinoderms to appear, ranging from the Early Cambrian to the Silurian. Most eocrinoids were sessile and fed with their long brachioles (the arm-like structures, which in this specimen are spirally twisted). The body was covered by plates; in early eocrinoids the holdfast was also covered by plates, but later eocrinoids evolved a stalk with columnals, like crinoids and blastoids.
The largest excellently preserved eocrinoid fossil measures approximately 2 5/8 inches long. The matrix measures approximately 8 1/2 inches long by
5 3/8 inches wide. There are also a couple of small eocrinoids on the reverse side of the plate.
El Kaid Errami, Morocco
ITEM# INVERT-Morocco-0007
This is an excellent example of the eocrinoid Ascocystites sp. From the Lower Ordovician of Morocco. Ascocystites sp. is a member of the Order , Family Ascocystitidae.
The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian.
The eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera, Diploporita, Coronoidea, Blastoidea, Parablastoidea, and Paracrinoidea. The earliest genera had a short holdfast and irregularly structured plates. Later forms had a fully developed stalk with regular rows of plates. They were benthic suspension feeders, with five ambulacra on the upper surface, surrounding the mouth and extending into a number of narrow arms. An unusual Ordovician form was the conical Bolboporites with its single brachiole.
Eocrinoids are among the earliest groups of echinoderms to appear, ranging from the Early Cambrian to the Silurian. Most eocrinoids were sessile and fed with their long brachioles (the arm-like structures, which in this specimen are spirally twisted). The body was covered by plates; in early eocrinoids the holdfast was also covered by plates, but later eocrinoids evolved a stalk with columnals, like crinoids and blastoids.
The largest excellently preserved eocrinoid fossil measures approximately 2 5/8 inches long. The matrix measures approximately 8 1/2 inches long by
5 3/8 inches wide. There are also a couple of small eocrinoids on the reverse side of the plate.
$
250.00
Eocrinoid - Ascocystites sp.
Lower Ordovician
El Kaid Errami, Morocco
ITEM# INVERT-Morocco-0006
This is an excellent example of the eocrinoid Ascocystites sp. From the Lower Ordovician of Morocco. Ascocystites sp. is a member of the Order , Family Ascocystitidae.
The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian.
The eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera, Diploporita, Coronoidea, Blastoidea, Parablastoidea, and Paracrinoidea. The earliest genera had a short holdfast and irregularly structured plates. Later forms had a fully developed stalk with regular rows of plates. They were benthic suspension feeders, with five ambulacra on the upper surface, surrounding the mouth and extending into a number of narrow arms. An unusual Ordovician form was the conical Bolboporites with its single brachiole.
Eocrinoids are among the earliest groups of echinoderms to appear, ranging from the Early Cambrian to the Silurian. Most eocrinoids were sessile and fed with their long brachioles (the arm-like structures, which in this specimen are spirally twisted). The body was covered by plates; in early eocrinoids the holdfast was also covered by plates, but later eocrinoids evolved a stalk with columnals, like crinoids and blastoids.
The larger excellently preserved eocrinoid fossil measures approximately 2 1/2 inches long. The matrix measures approximately 3 7/8 inches long by
2 1/2 inches wide.
El Kaid Errami, Morocco
ITEM# INVERT-Morocco-0006
This is an excellent example of the eocrinoid Ascocystites sp. From the Lower Ordovician of Morocco. Ascocystites sp. is a member of the Order , Family Ascocystitidae.
The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian.
The eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera, Diploporita, Coronoidea, Blastoidea, Parablastoidea, and Paracrinoidea. The earliest genera had a short holdfast and irregularly structured plates. Later forms had a fully developed stalk with regular rows of plates. They were benthic suspension feeders, with five ambulacra on the upper surface, surrounding the mouth and extending into a number of narrow arms. An unusual Ordovician form was the conical Bolboporites with its single brachiole.
Eocrinoids are among the earliest groups of echinoderms to appear, ranging from the Early Cambrian to the Silurian. Most eocrinoids were sessile and fed with their long brachioles (the arm-like structures, which in this specimen are spirally twisted). The body was covered by plates; in early eocrinoids the holdfast was also covered by plates, but later eocrinoids evolved a stalk with columnals, like crinoids and blastoids.
The larger excellently preserved eocrinoid fossil measures approximately 2 1/2 inches long. The matrix measures approximately 3 7/8 inches long by
2 1/2 inches wide.
$
100.00
Invertebrate - Acervularia sp.
Devonian
Smara area, West Sahara, Morocco
ITEM# INVERT-Morocco-0005
This is a museum-quality specimen of Acervularia sp., a colonial “sun” coral from the Devonian, Smara area, West Sahara, Morocco. Acervularia sp. is a rugose coral from the Order Stauriida, Family Acervulariidae.
The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permain seas.
Solitary rugose corals are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose wall. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies. When radiating septa were present, they were usually in multiples of four, hence Tetracoralla in contrast to modern Hexacoralla, colonial polyps generally with sixfold symmetry.
Rugose corals have a skeleton made of calcite that is often fossilized. Like modern corals, rugose corals were invariably benthic, living on the sea floor or in a reef-framework. Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey. They also had tentacles to help them catch prey. Technically they were carnivores, but prey-size was so small they are often referred to as microcarnivores.
Species of Acervularia:
Smara area, West Sahara, Morocco
ITEM# INVERT-Morocco-0005
This is a museum-quality specimen of Acervularia sp., a colonial “sun” coral from the Devonian, Smara area, West Sahara, Morocco. Acervularia sp. is a rugose coral from the Order Stauriida, Family Acervulariidae.
The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permain seas.
Solitary rugose corals are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose wall. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies. When radiating septa were present, they were usually in multiples of four, hence Tetracoralla in contrast to modern Hexacoralla, colonial polyps generally with sixfold symmetry.
Rugose corals have a skeleton made of calcite that is often fossilized. Like modern corals, rugose corals were invariably benthic, living on the sea floor or in a reef-framework. Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey. They also had tentacles to help them catch prey. Technically they were carnivores, but prey-size was so small they are often referred to as microcarnivores.
Species of Acervularia:
- Acervularia ananas
- Acervularia anulata
- Acervularia davidsoni
- Acervularia goldfusii
- Acervularia impressa
- Acervularia luxurians
- Acervularia sp.
$
300.00
Invertebrate - Phillipsastrea sp. or Acervularia sp.?
Middle Devonian - 375 mya
Atlas Mountains, Morocco
ITEM # INVERT-Morocco-0001
This coral identified as a "sun" coral and is from the Devonian of Morocco.
The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permain seas.
Solitary rugose corals are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose wall. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies. When radiating septa were present, they were usually in multiples of four, hence Tetracoralla in contrast to modern Hexacoralla, colonial polyps generally with sixfold symmetry.
Rugose corals have a skeleton made of calcite that is often fossilized. Like modern corals, rugose corals were invariably benthic, living on the sea floor or in a reef-framework. Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey. They also had tentacles to help them catch prey. Technically they were carnivores, but prey-size was so small they are often referred to as microcarnivores.
This specimen is approximately 6 5/8 inches long by 4 1/2 inches wide.
SORRY, THIS ITEM IS SOLD!!.
Atlas Mountains, Morocco
ITEM # INVERT-Morocco-0001
This coral identified as a "sun" coral and is from the Devonian of Morocco.
The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permain seas.
Solitary rugose corals are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose wall. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies. When radiating septa were present, they were usually in multiples of four, hence Tetracoralla in contrast to modern Hexacoralla, colonial polyps generally with sixfold symmetry.
Rugose corals have a skeleton made of calcite that is often fossilized. Like modern corals, rugose corals were invariably benthic, living on the sea floor or in a reef-framework. Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey. They also had tentacles to help them catch prey. Technically they were carnivores, but prey-size was so small they are often referred to as microcarnivores.
This specimen is approximately 6 5/8 inches long by 4 1/2 inches wide.
SORRY, THIS ITEM IS SOLD!!.
$
40.00
Invertebrate - Arachnophylum sp.
Middle Devonian - 375 mya
Tafilalet, Morocco
ITEM # INVERT-Morocco-0002
This fossil specimen is a colonial coral named Arachnophylum sp. from the Middle Devonian of Morocco. Arachnophylum sp. is a rugose coral.
Although corals first appeared in the Cambrian period, some 542 million years ago, fossils are extremely rare until the Ordovician period, 100 million years later, when rugose and tabulate corals became widespread.
Rugose corals became dominant by the middle of the Silurian period, and became extinct early in the Triassic period. The rugose corals existed in solitary and colonial forms, and were also composed of calcite.
The scleractinian corals filled the niche vacated by the extinct rugose and tabulate species. Their fossils may be found in small numbers in rocks from the Triassic period, and became common in the Jurassic and later periods. Scleractinian skeletons are composed of a form of calcium carbonate known as aragonite. Although they are geologically younger than the tabulate and rugose corals, their aragonitic skeleton is less readily preserved, and their fossil record is less complete.
Although present day corals can catch small fish and plankton, using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular algae called zooxanthellae that live within the coral's tissue. Such corals require sunlight and grow in clear, shallow water, typically at depths shallower than 60 metres (200 ft). Corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia. Other corals do not have associated algae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3,000 metres (9,800 ft).
At certain times in the geological past, corals were very abundant. Like modern corals, these ancestors built reefs, some of which ended as great structures in sedimentary rocks.
Fossils of fellow reef-dwellers algae, sponges, and the remains of many echinoids, brachiopods, bivalves, gastropods, and trilobites appear along with coral fossils. This makes some corals useful index fossils that enabled geologists to date the rocks in which they are found. Coral fossils are not restricted to reef remnants, and many solitary fossils may be found elsewhere, such as Cyclocyathus, which occurs in England's Gault clay formation.
A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. They are found predominantly in Michigan's Upper Peninsula, and the northwestern portion of Michigan's Lower Peninsula.
This specimen is approximately 2 1/4 inches long by 2 3/8 inches wide.
Tafilalet, Morocco
ITEM # INVERT-Morocco-0002
This fossil specimen is a colonial coral named Arachnophylum sp. from the Middle Devonian of Morocco. Arachnophylum sp. is a rugose coral.
Although corals first appeared in the Cambrian period, some 542 million years ago, fossils are extremely rare until the Ordovician period, 100 million years later, when rugose and tabulate corals became widespread.
Rugose corals became dominant by the middle of the Silurian period, and became extinct early in the Triassic period. The rugose corals existed in solitary and colonial forms, and were also composed of calcite.
The scleractinian corals filled the niche vacated by the extinct rugose and tabulate species. Their fossils may be found in small numbers in rocks from the Triassic period, and became common in the Jurassic and later periods. Scleractinian skeletons are composed of a form of calcium carbonate known as aragonite. Although they are geologically younger than the tabulate and rugose corals, their aragonitic skeleton is less readily preserved, and their fossil record is less complete.
Although present day corals can catch small fish and plankton, using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular algae called zooxanthellae that live within the coral's tissue. Such corals require sunlight and grow in clear, shallow water, typically at depths shallower than 60 metres (200 ft). Corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia. Other corals do not have associated algae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3,000 metres (9,800 ft).
At certain times in the geological past, corals were very abundant. Like modern corals, these ancestors built reefs, some of which ended as great structures in sedimentary rocks.
Fossils of fellow reef-dwellers algae, sponges, and the remains of many echinoids, brachiopods, bivalves, gastropods, and trilobites appear along with coral fossils. This makes some corals useful index fossils that enabled geologists to date the rocks in which they are found. Coral fossils are not restricted to reef remnants, and many solitary fossils may be found elsewhere, such as Cyclocyathus, which occurs in England's Gault clay formation.
A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. They are found predominantly in Michigan's Upper Peninsula, and the northwestern portion of Michigan's Lower Peninsula.
This specimen is approximately 2 1/4 inches long by 2 3/8 inches wide.
$
30.00
Invertebrate - Arachnophylum sp.
Middle Devonian - 375 mya
Tafilalet, Morocco
ITEM # INVERT-Morocco-0003
This fossil specimen is a colonial coral named Arachnophylum sp. from the Middle Devonian of Morocco. Arachnophylum sp. is a rugose coral.
Although corals first appeared in the Cambrian period, some 542 million years ago, fossils are extremely rare until the Ordovician period, 100 million years later, when rugose and tabulate corals became widespread.
Rugose corals became dominant by the middle of the Silurian period, and became extinct early in the Triassic period. The rugose corals existed in solitary and colonial forms, and were also composed of calcite.
The scleractinian corals filled the niche vacated by the extinct rugose and tabulate species. Their fossils may be found in small numbers in rocks from the Triassic period, and became common in the Jurassic and later periods. Scleractinian skeletons are composed of a form of calcium carbonate known as aragonite. Although they are geologically younger than the tabulate and rugose corals, their aragonitic skeleton is less readily preserved, and their fossil record is less complete.
Although present day corals can catch small fish and plankton, using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular algae called zooxanthellae that live within the coral's tissue. Such corals require sunlight and grow in clear, shallow water, typically at depths shallower than 60 metres (200 ft). Corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia. Other corals do not have associated algae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3,000 metres (9,800 ft).
At certain times in the geological past, corals were very abundant. Like modern corals, these ancestors built reefs, some of which ended as great structures in sedimentary rocks.
Fossils of fellow reef-dwellers algae, sponges, and the remains of many echinoids, brachiopods, bivalves, gastropods, and trilobites appear along with coral fossils. This makes some corals useful index fossils that enabled geologists to date the rocks in which they are found. Coral fossils are not restricted to reef remnants, and many solitary fossils may be found elsewhere, such as Cyclocyathus, which occurs in England's Gault clay formation.
A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. They are found predominantly in Michigan's Upper Peninsula, and the northwestern portion of Michigan's Lower Peninsula.
This excellently preserved specimen is approximately 3 inches long by 2 5/8 inches wide.
Tafilalet, Morocco
ITEM # INVERT-Morocco-0003
This fossil specimen is a colonial coral named Arachnophylum sp. from the Middle Devonian of Morocco. Arachnophylum sp. is a rugose coral.
Although corals first appeared in the Cambrian period, some 542 million years ago, fossils are extremely rare until the Ordovician period, 100 million years later, when rugose and tabulate corals became widespread.
Rugose corals became dominant by the middle of the Silurian period, and became extinct early in the Triassic period. The rugose corals existed in solitary and colonial forms, and were also composed of calcite.
The scleractinian corals filled the niche vacated by the extinct rugose and tabulate species. Their fossils may be found in small numbers in rocks from the Triassic period, and became common in the Jurassic and later periods. Scleractinian skeletons are composed of a form of calcium carbonate known as aragonite. Although they are geologically younger than the tabulate and rugose corals, their aragonitic skeleton is less readily preserved, and their fossil record is less complete.
Although present day corals can catch small fish and plankton, using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular algae called zooxanthellae that live within the coral's tissue. Such corals require sunlight and grow in clear, shallow water, typically at depths shallower than 60 metres (200 ft). Corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia. Other corals do not have associated algae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3,000 metres (9,800 ft).
At certain times in the geological past, corals were very abundant. Like modern corals, these ancestors built reefs, some of which ended as great structures in sedimentary rocks.
Fossils of fellow reef-dwellers algae, sponges, and the remains of many echinoids, brachiopods, bivalves, gastropods, and trilobites appear along with coral fossils. This makes some corals useful index fossils that enabled geologists to date the rocks in which they are found. Coral fossils are not restricted to reef remnants, and many solitary fossils may be found elsewhere, such as Cyclocyathus, which occurs in England's Gault clay formation.
A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. They are found predominantly in Michigan's Upper Peninsula, and the northwestern portion of Michigan's Lower Peninsula.
This excellently preserved specimen is approximately 3 inches long by 2 5/8 inches wide.
$
30.00
Invertebrate - Scyphocrinus elegans
Upper Silurian 420 mya
South Morocco
ITEM # INVERT-Morocco-0004
This is an museum-quality example of the criniod Scyphocrinus elegans from the Upper Silurian of South Morocco.
Crinoids, also known as sea lilies or feather-stars, are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters.
Crinoids are characterized by a mouth on the top surface that is surrounded by feeding arms. They have a U-shaped gut, and their anus is located next to the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognized, most crinoids have many more than five arms. Crinoids usually have a stem used to attach themselves to a substrate, but many live attached only as juveniles and become free-swimming as adults.
Crinoids comprise three basic sections; the stem, the calyx, and the arms. The stem is composed of highly porous ossicles which are filled with muscular tissue. The calyx contains the crinoid's digestive and reproductive organs, and the mouth is located at the top of the dorsal cup, while the anus is located peripheral to it. The arms display pentameral symmetry and comprise smaller ossicles than the stem and are equipped with cirri which facilitate feeding by moving the organic media down the arm and into the mouth.
The majority of living crinoids are free-swimming and have only a vestigial stalk. In those deep-sea species that still retain a stalk, it may reach up to 1 metre (3.3 ft) in length, although it is usually much smaller. The stalk grows out of the aboral surface, which forms the upper side of the animal in starfish and sea urchins, so that crinoids are effectively upside-down by comparison with most other echinoderms. The base of the stalk consists of a disc-like sucker, which, in some species, has root-like structures that further increase its grip on the underlying surface. The stalk is often lined by small cirri.
The earliest known crinoids come from the Ordovician. They are thought to have evolved from primitive echinoderms known as Eocystoids. Confusingly, another early group of echinoderms were also the Eocrinoids, but that group is currently thought to be an ancestor of blastoids rather than of crinoids.
The crinoids underwent two periods of abrupt adaptive radiation; the first during the Ordovician, the other after they underwent a selective mass extinction at the end of the Permian period.] This Triassic radiation resulted in forms possessing flexible arms becoming widespread; motility, predominantly a response to predation pressure, also became far more prevalent. After the end-Permian extinction, crinoids never regained the morphological disparity they enjoyed in the Paleozoic; they occupied a different region of morphospace, employing different ecological strategies from those that had proven so successful in the Paleozoic.
The long and varied geological history of the crinoids demonstrates how well the echinoderms have adapted to filter-feeding. The fossils of other stalked filter-feeding echinoderms, such as blastoids, are also found in the rocks of the Palaeozoic era. These extinct groups can exceed the crinoids in both numbers and variety in certain horizons. However, none of these others survived the crisis at the end of the Permian period.
Huge plate of specimens measuring approximately 20 inches wide by 24 inches long. Measured diagonally and at its widest point it measures over 28 inches long.
South Morocco
ITEM # INVERT-Morocco-0004
This is an museum-quality example of the criniod Scyphocrinus elegans from the Upper Silurian of South Morocco.
Crinoids, also known as sea lilies or feather-stars, are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters.
Crinoids are characterized by a mouth on the top surface that is surrounded by feeding arms. They have a U-shaped gut, and their anus is located next to the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognized, most crinoids have many more than five arms. Crinoids usually have a stem used to attach themselves to a substrate, but many live attached only as juveniles and become free-swimming as adults.
Crinoids comprise three basic sections; the stem, the calyx, and the arms. The stem is composed of highly porous ossicles which are filled with muscular tissue. The calyx contains the crinoid's digestive and reproductive organs, and the mouth is located at the top of the dorsal cup, while the anus is located peripheral to it. The arms display pentameral symmetry and comprise smaller ossicles than the stem and are equipped with cirri which facilitate feeding by moving the organic media down the arm and into the mouth.
The majority of living crinoids are free-swimming and have only a vestigial stalk. In those deep-sea species that still retain a stalk, it may reach up to 1 metre (3.3 ft) in length, although it is usually much smaller. The stalk grows out of the aboral surface, which forms the upper side of the animal in starfish and sea urchins, so that crinoids are effectively upside-down by comparison with most other echinoderms. The base of the stalk consists of a disc-like sucker, which, in some species, has root-like structures that further increase its grip on the underlying surface. The stalk is often lined by small cirri.
The earliest known crinoids come from the Ordovician. They are thought to have evolved from primitive echinoderms known as Eocystoids. Confusingly, another early group of echinoderms were also the Eocrinoids, but that group is currently thought to be an ancestor of blastoids rather than of crinoids.
The crinoids underwent two periods of abrupt adaptive radiation; the first during the Ordovician, the other after they underwent a selective mass extinction at the end of the Permian period.] This Triassic radiation resulted in forms possessing flexible arms becoming widespread; motility, predominantly a response to predation pressure, also became far more prevalent. After the end-Permian extinction, crinoids never regained the morphological disparity they enjoyed in the Paleozoic; they occupied a different region of morphospace, employing different ecological strategies from those that had proven so successful in the Paleozoic.
The long and varied geological history of the crinoids demonstrates how well the echinoderms have adapted to filter-feeding. The fossils of other stalked filter-feeding echinoderms, such as blastoids, are also found in the rocks of the Palaeozoic era. These extinct groups can exceed the crinoids in both numbers and variety in certain horizons. However, none of these others survived the crisis at the end of the Permian period.
Huge plate of specimens measuring approximately 20 inches wide by 24 inches long. Measured diagonally and at its widest point it measures over 28 inches long.
$
2,500.00
