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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.
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Lemon Shark and Sand Tiger Shark Teeth; Identification and Interesting Facts

April 3, 2022 by Fossillady

Lemon Shark

Lemon Shark (Negaprion brevirostris) Fossil Teeth (3/4 inch (1.9 cm) long)

Lemon Shark, Negaprion brevirostris, first appeared in the fossil record approximately 50 millions-years-ago beginning in the Eocene Epoch and are still here today, but are nearing the threatened list!

Named for their yellowish-brown color, which helps to disguise the fish over a yellowish-gray seabed, Lemon Sharks prefer coastal waters, lagoons or mangroves, typically staying close to the water surface. Even though humans reside in these areas, they are of little threat.

They are large, heavy sharks growing to an average length around 10 feet (3 meters). The Lemon Shark has a flattened head with a short, broad snout. Three of their triangular dorsal fins are approximately the same size and shape, which is unusual compared to other sharks.

Lemon sharks are commonly found along the Southeastern Coasts of the United States and the Gulf of Mexico, and can also be found throughout the Caribbean and Southern Brazil. They have also been known to migrate to places as far east as West Africa.

Lemon Shark teeth have fairly large roots which are near straight across the top. The blades are smooth and narrow coming to a sharp point and typically grow out from the root at a 90 degree angle.

  • Lemon Sharks can live to near 30 years.
Top: Lemon Shark Bottom Left: Sand Tiger Shark Right: Great White Shark

Sand Tiger Shark

Sand Tiger Shark, Carcharia taurus, first appeared in the fossil record during the late Cretaceous Period, around 72 million-years-ago, replacing their predecessor, the extinct Sand Tiger Shark, Carcharias cuspidatus, which appeared more than 45 million years earlier. Like the Lemon Shark, Sand Tiger Sharks are also threatened today.

Sand Tiger sharks inhabit coastal sandy shorelines (hence the name sand tiger shark). They also inhabit shallow bars, estuaries and tropical reefs to a depth of around 627 feet (191 meters). Even though they roam the surf in close proximity to humans, they are of little threat. They are normally quite docile, plus their mouths are not large enough to cause a human fatality.

Sand Tiger sharks dwell in a wide-range of waters including off the east coasts of North and South America, Japan, Australia, Africa, and parts of the Mediterranean. Because they have a worldwide distribution, they have inherited several common names, including; grey nurse shark, spotted ragged-tooth shark or blue-nurse sand tiger. The term “sand tiger shark” actually refers to four different Sand Tiger shark species in the family, Odontaspididae.

Sand Tiger Shark (Carcharias taurus) – 2 Upper Teeth and 1 Side Tooth (Longest sample is 1 inch (2.5 cm) long)

Sand Tiger shark, Carcharia taurus, are large and bulky reaching up to approximately 10 feet (3 meters) in length. The head is pointy, while the snout is flattened and the mouth extends beyond the eyes. The Sand Tiger has a light grey-brownish back and pale underside. Adults tend to have reddish-brown scattered spots, mostly on the hind part of the body.

Sand Tiger Sharks usually swim with an opened mouth displaying three rows of protruding, smooth-edged, sharp-pointed teeth that have side cuplets, which once removed from the mouth, may or may not later become worn away. The upper front teeth are separated from the side teeth by small intermediate teeth. The roots are deeply curvaceous.

  • Sand Tiger sharks can live up to 40 years.

Other Shark Facts

  • Sharks are covered in scales called dermal denticles, which are covered with a layer of enamel, like our teeth. The denticles protect the shark’s skin from injury. They also help water glide over the shark as it swims so it can move quickly and quietly through the ocean.
  • Sharks need to keep moving in order to pass water through their gills to receive oxygen.
  • The dark color over their topside helps to camouflage them from above while the light color on their bottom side blends with the sunlight to fool their prey below.
  • Sharks have electro sensors to help them navigate and find prey, compensating for their poor eyesight.
  • Sharks lack bones, their bodies are mostly made up of flexible cartilage which is lighter than bone requiring less energy for them to stay afloat.
  • Sharks loose and replace their teeth on a regular basis.


Factors Contributing to Population Declines of Sand Tiger and Lemon Sharks

  • Over fishing, particularly, by eastern countries such as China and Japan
  • Pollution in estuaries where pups are bred
  • Competition with humans for food
  • Exploitive Fishing Nets

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Shark Teeth Fossils lemon shark informationlemon shark teethsand tiger shark informationsand tiger shark teeththreats to sharks 2 Comments

Megalodon Vs. Great White Shark Vs. Extinct White Shark

March 13, 2022 by Fossillady
Megalodon Vs. Great White Shark Comparison Pencil Drawing

You can find plenty of information on the internet and in books about both of these fascinating creatures, but the magnitude of Megalodon’s girth is mind blowing. The above photo depicts both species most exceptional sizes found in the fossil records.

Due to the multitude of unearthed shark teeth, scientists have been able to determine size, species and age of these amazing creatures. Surprisingly, scientists were able to determine that the largest Megalodons ‘”Otodus megalodon” were female, as with the Great Whites “Carcharodon carcharias” of today.

Sharks are important to all life on earth keeping the oceans clean of dead debris. Without them, our oceans would be overrun with bad bacteria killing all other ocean life which feed the world.

Great White Shark Tooth Front and Underside (Lingual Side and Labial Side) 2 Inches (5 cm) long

On average, Great White sharks have approximately 300 teeth, but lose dozens of them per month, which are readily replaced by several rows of backup teeth. In a single lifetime, these sharks can acquire over 20,000 teeth. This would explain why the average beachcomber can readily find volumes of shark teeth to add to their collections! Megalodon had almost as many teeth as the Great Whites, but considering Megalodon’s approximately 20 million-year-timespan on Earth, compared to Great Whites approximate 6 million-year-timespan, it’s not surprising Meg teeth are equally as common to find, if not more.

Megalodon Shark Tooth (5 inches (13 cm) Long

Comparing Shark Teeth Characteristics

In comparison, Megalodon shark teeth have larger, wider roots than the Great White sharks and typically display a medium to wide bourlette (chevron shaped space between the root and the crown of the tooth). Also, the Megalodon teeth displayed small, regular spaced serrations along the edges, while the Great White shows thicker, irregular serrations.

The tooth size is another way to tell these two species apart, depending if the tooth is from a juvenile Meg or an adult Meg. The largest Megalodon tooth ever found is just over 7 inches (18cm) long, filling a mans palm. The largest recorded Great White shark tooth is just over 3 inches (7.5cm) long.

Scale Pencil Drawing of Megalodon Jaw and Teeth

Where can you find Megalodon teeth?

Megalodon shark teeth have been found on every continent except Antarctica. And in the United States, their teeth have been found in every state along the East Coast, especially Florida and the Carolinas. Their teeth have also been found in Texas, Louisiana, California, Washington, Hawaii, Michigan and some other Midwestern states. The best environments to find shark teeth are beaches, creek beds, dried riverbeds and abandoned dig sites.

Why did Megalodon become extinct?

Megalodon teeth fossils date from the early Miocene Epoch about 23 million-years-ago until the end of the Pliocene Epoch about 2.58 million-years-ago. Modern Great Whites evolved from the middle of the Miocene Epoch around 10 million-years-ago to the present. Consequently, the Great Whites lived toward the end of Megalodon’s tenure and scientists predict they competed with juvenile Megalodons for food making it more difficult for some Megalodons to reach adulthood. Also, changing ocean currents resulting in colder temperatures drove one of Megalodon’s essential prey of whales to colder climates, which Megalodon may not have adapted. A megaton creature needs megatons of food to survive and scientists predict the species was likely starved out of existence.

White Shark Fossil Tooth – 2 inches (5cm) Long

Extinct White Shark Comparisons

The above shark teeth belonged to a known extinct breed of large White Sharks, Carcharodon hastalis, a fast-swimming mackerel shark. This impressive species of sharks are considered ancestors to the modern day Great White Sharks, Carcharodon carcharias. The teeth of White Sharks have been found world-wide from marine deposits of the Miocene and Pliocene epochs, around 20 million to 3 million-years-ago. They dominated the Miocene seas and likely competed with Megalodon for food.

White Shark teeth are often found along with the teeth of Megs and on average measure from 1-3 inches (2.5 – 7.5 cm) long, topping out at 4 inches (10 cm) long, second only to Megalodon. Roots of these extinct White Shark teeth are large, but not as broad in comparison to Megs. White Shark teeth crowns also lack the edge serrations and chevron shaped bourlette between the crown and roots distinguishable in Megalodon’s.

White Sharks, Carcharodon hastalis, grew larger than today’s Great Whites, Carcharodon carcharias, reaching estimated lengths of 20 to 26 feet (6–8 meters). While modern Great Whites, typically max out around 20 feet.

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Stromatolites Lake Michigan Discovery

February 12, 2018 by Fossillady
Lake Michigan Stromatolite Fossil (Same as sample below, wetted to bring out layers)
Stromatolites Lake Michigan Beach Fossil

You’re strolling along the shoreline of Lake Michigan combing the beach for interesting stones and driftwood or perhaps beach glass. You find a common gray beach stone and admire it for the smooth way it feels in your hand, ground down by the wind, wave and sand action of the big lake. It even smells of the fresh outdoors. But upon a closer look, you can see layers of striations interesting and beautiful. When wet, they suddenly pop out and there’s no mistaken this is not an ordinary mineral rock. It’s a stromatolite.

DSC01201-studio
Lake Michigan Stromatolite Fossil

What Are Stromatolites?

For us laymen, simply put, they are fossils of bacteria. You need a firm understanding of biology, geology and chemistry to fully understand them. Nevertheless, I will attempt to delve into their fascinating formation.

Forming in water, scientists today generally agree stromatolites are layered structures formed by cyanobacteria, single-cell microorganisms capable of photosynthesis producing their own food. Cyanobacteria are prokaryotic cells (the simplest form of modern carbon-based life) in that they lack a DNA nucleus. Bacteria, including the photosynthetic cyanobacteria, were the only form of life on Earth for the first two billion years that life existed on Earth.

Forming The Layers

The stromatolite bacteria live in between thin sheets of filament bound together by a sticky substance. Photosynthesis in the bacteria depletes carbon dioxide in the surrounding water making it less acidic and initiating the release of calcium carbonate. Calcium carbonate and other minerals and grains of sediment settle, then get trapped on the outside sticky layer. The cyanobacteria thus rises to the top of the stromatolite structure over the sediment and the layers recycle repeatedly building the solid structures that can take several forms such as mounds, sheets or columns which appear like giant mushrooms.

The stromatolites forming today in the shallow waters of Shark Bay, Australia are built by colonies of microbes. Credit: University of Wisconsin-Madison
  • While the microbes that construct the layered mats generally are not preserved, the wrinkled calcium carbonate, mineral rich layers remain in the fossilized forms.

Earliest Stromatloites

Stromatolites are the oldest discovered fossils dating as far back as 3.5 billion years. First appearing during the Archean Eon, their heyday was during the Upper Proterozoic Eon long before multi cellular Cambrian creatures evolved.

Modern Discovery

Modern stromatolites were first discovered growing in the salty waters of Shark Bay, Australia in 1956. Before then, scientists believed they were extinct. Other locations discovered around the globe include the shallow waters of Yellow Stone, Mexico, Canada, Brazil, Oregon and most uniquely, Bahamas. Stromatolites lost out when animals such as snails evolved that ate them. Modern stromatolites thus live in water too salty or hot for those predators, except in the Bahamas.

Stromatolites in the Soeginina Beds (Paadla Formation, Ludlow-Silurian)
near the village of Kübassaare, Saaremaa, Estonia Credit

Studies of modern stromatolites have shone they are not uniform in shape and form. They host a variety of bacteria and archaea (bacteria like microorganisms). Archaea usually live in extreme, often very hot or salty environments such as hydrothermal vents or mineral hot springs, i.e.Yellow Stone. Various biological environmental conditions may attribute to the differences in their make-up and shapes. Some form a round ball or lumpy mass. The example below shows one of these such forms found on a Lake Michigan beach, red in color likely from iron infused sediment.

Lake Michigan Stromatolite Fossil

Some of the most ancient stromatolite fossils found are 3.35 billion years old from the Strelley Pool chert of Western Australia, part of a fossilized ocean reef. Seven different types have been identified indicating diversity from early on. The stromatolite fossils found in Michigan are typically younger, dating from 2.2 billion years ago. During the great ice age approximately 10,000 years ago, glaciers cut the Great Lakes digging up time-buried layers of sediment containing many varieties of fossils we find on the beaches today. This could explain how I picked up the stromatolite fossils pictured above on the beach in Southwestern Michigan.

Lake Michigan Stromatolite Fossil

Why Are Stromatolites Important To All Life?

Cyanobacteria that make up stromatolites were ultimately responsible for one of the most important global changes that the Earth has undergone. Being photosynthetic, cyanobacteria produce oxygen as a by-product. Photosynthesis is the only major source of free oxygen gas in the atmosphere. As stromatolites became more common 2.5 billion years ago, they gradually changed the Earth’s atmosphere from a carbon dioxide-rich mixture to the present day oxygen-rich atmosphere. This major change paved the way for the next evolutionary step, the appearance of life based on the eukaryotic cell (cell with a nucleus).

Stromatolites at Highborne Cay, in the Exumas, The Bahamas https://en.wikipedia.org/wiki/Stromatolite

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From Tree to Stone

November 26, 2017 by Fossillady
Triassic Period, Araucarioxylon, arizonicum (Petrified Forest National Park) Drawing Rendition

The drawing above is a rendition I drew with colored pencils of Araucarioxylon, arizonicum, an extinct conifer tree identified from the petrified wood from the infamous Petrified Forest National Park located in the U.S. State of Arizona. Originally, it was thought to be a distant relative of the Araucaria tree or the Norfolk Pine, which you often see for sale during the Christmas season as potted plants. Without detailed microscopic examination of the wood, its link to present day trees is only speculation at this point. Modern scientific discoveries indicates there were more species than originally thought lying on the dry Arizona plateau.

Triassic Period Araucarioxylon, arizonicum petrified wood fossil from Arizona Petrified Wood National Park

Triassic Beginnings

During the Triassic Period, around 225 million years ago, the present day continents were melded together as one supercontinent called Pangea. By the end of the era, around 200 million years ago, widespread volcanic activity began to break the continents apart. The first dinosaurs and mammals had evolved and there had been a boom in cycads (palm like trees), giant tree ferns and conifers . . .  enter the Araucarioxylon of Arizona, a type of conifer or pine. It differs from modern day conifers with its sporadic branch growth pattern around the trunk rather than growing in level whorls. It grew up to 200 feet (60 meters) tall with a 9 foot (2.7 m) diameter. Compare that to the tallest current living conifers, the Sequoias, that grow up to 188 feet (57 meters). To help put that into perspective, maple trees reach up to about 50 feet (15 m) and oak trees top out at about 80 feet (24m) tall.

Triassic Landscape

From Tree To Stone

The high and dry tableland in northern Arizona where the National Petrified Forest Park rests, was a vast flood plain during the Triassic Period overflowing with streams and widespread ponds. Prehistoric, extinct plants and trees concentrated along the spilling bodies of water. Dying or blown over trees were washed down the streams into the flood plains where they gathered and decayed. If they were buried under mud, silt or volcanic ash deep enough to cut off oxygen, it slowed the decaying process. Silica laden groundwater gradually seeped through the logs replacing the original wood tissue with silica deposits. As the process continued over the ages, the wood was replaced, atom by atom, with silica crystallized into mineral rich quartz, ultimately turning the wood into a rather attractive stone.

DSC07806
Triassic Petrified Wood Fossil Araucarioxylon, arizonicum from Petrified Forest National Park

Petrified Wood Colors

Various colors, often striking, are produced depending on the mineral contents in the stone:

PINK or RED – Hematite present – a form of oxidized iron – This interesting process is well explained from ScienceView.com. Iron dissolves in ground water when no oxygen is present. The ground water becomes re-oxygenated as it moves though the tree trunks causing oxygen to bond with the iron. The iron then precipitates to produce a solid form of iron called hematite. This hematite is incorporated into the log’s cell walls. The same process occurs when iron stains porcelain sinks. The soluble iron in ground water becomes oxidized into a solid form when it comes in contact with air, causing a reddish stain.

YELLOW BROWN or ORANGE – Goethite present- a weathered hydrated iron oxide that becomes crystallized

GREEN – Pure native iron present

WHITE  – Pure Silica present – Silicon, Si, and oxygen, O, are the two most abundant elements in the earth’s crust which together form silica dioxide quartz

BLACK – Carbon or Pyrite or Iron Sulfide (the most wide spread sulfide) present – The wood was affected as hydrogen sulfide from decaying organic matter interacted with iron forming pyrite.

PURPLE or BLUE – Manganese present – This is a secondary material formed when water leaches manganese from igneous rock and re-deposits it as a concentration of manganese dioxide.

TAN –  Silica Dioxide present – naturally found in water, plants, animals, and the earth

Uplift

How did the petrified wood of Arizona become uncovered? First, millions of years ago, the area sank to the point which completely flooded everything with freshwater sediments. It continued to sink deeper becoming completely buried. Millions of years later, the area was lifted far above sea level from westerly continental plate pressure. The uplift created stresses that cracked the giant logs. Over time, wind and water have worn away the layers of hardened sediments, exposing the fossilized wood.

Lake Michigan Petrified Driftwood

Petrified Driftwood Lake Michigan Beach

While the Petrified Forest of Arizona has the highest concentration of petrified wood in the world, it can be found in every US state and other countries around the world. I found this sample of petrified driftwood on a Southwest Michigan beach off Lake Michigan called Oval Beach. It’s predominantly gray with a slight bluish green cast and has a few streaks of rust. In certain light, it casts a very bright sheen or luster. It’s difficult to capture the sheen in a photograph, but you can get a better idea from its flip side in the photo below.

Petrified Driftwood Lake Michigan Beach

After researching the possible mineral contents of my sample, according to its dense property, color and luster, my best guess tells me that it’s hematite specularite. I have collected driftwood on the beach very often, but never before a piece that was petrified!

See a sample of petrified wood of extinct scale trees, from one of my previous posts.

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Timetable of Clams

April 2, 2017 by Fossillady
Scan_Pic0008b
Timetable of Bivalve (Clams) Rendering Drawing

What is a clam and how do they live? “Clam” can be a term that covers all bivalves (pelecypods). Bivalves such as oysters and mussels attach themselves to hard objects, and scallops can free swim by flapping their valves together. Some clams bury themselves in sand and breathe by extending a tube to the water’s surface. Those varieties usually possess a stronger foot that looks like a tongue which the clam uses for digging and pushing itself along.

Clams feed by filtering plankton with their adapted gills, although the digging varieties use a siphoning tube and more primitive species used special tentacles. Bivalves lack a head or brain and usually have no eyes, although scallops are a notable exception. All bivalves possess a mouth, heart, kidneys, and anus, as well as a circulatory system. Clams haven’t changed much through the timetables surviving multiple earth changes and mass extinctions!

Clam Fossils Identification Colorcoded Matched with Drawing Clam Fossils – Oldest to Recent

gallery_77_673_13589
CTENODONTA FOSSIL CLAM Source

Orange Rendering: Ctendonta levata possesses a well developed beak, a smooth surface with fine concentric growth lines and teeth along the hinge plate. Lived from Ordovician to Silurian (505 to 408 million-years-ago) very old.

HPIM1520
MODIOLOPSIS FOSSIL CLAM

Deep Pinkish Rendering: Modiolopsis genus possess asymmetrical thin valves crossed by an oblique depression and strong beak. Possible fossil sample below is a mold of the inner shell which has been extremely smoothed by the movement of sand and waves. Lived from Ordovician to Silurian (505 to 408 million-years-ago)  

bi-byssonychia
BYSSONYCHIA FOSSIL CLAM Source

Blue/Green Rendering: Byssonychia genus has a sharp steeply inclined beak near the end of the hinge; usually has strong radial ribs. Mostly Upper Ordovician around 400 million-years-ago.

Timetable of Bivalve (Clams) Rendering Drawing
IMG_3872
GONIOPHORA FOSSIL CLAM Source

Brown Rendering: Goniophora levata has a lopsided shell with a prominent beak and ridge extending to the rear margin. Silurian to Devonian (438 to 360 million-yeas-ago)  

M012455
PTERIA FOSSIL CLAM Source

Goldish and Brown Rendering: Pteria colymbus genus has thin inequilaterally shaped valves with a long straight hinge merging into large unequal wings. Jurassic to recent (245 million-yeas-ago to recent)

image
GLYCIMERIS FOSSIL CLAM Source

Yellow Rendering: Glycimeris genus has symmetrical circular outline with pointed beak. Cretaceous to Recent (114 mya to recent)

PECTEN FOSSIL SCALLOP CLAM Source

Deep Blue/Purplish Colored Rendering: Pecten is a genus of many well known bivalves otherwise known as scallops. Valves have strong radial ribs and are almost symmetrical except for unequal wings. Mississippian to Recent (360 million-yeas-ago to recent)

                                                             

Bivalves feed the world. Bivalve oysters, scallops and clams are near the bottom of the food chain which many marine and freshwater species depend on for a food source. But don’t forget about land creatures such as otters, for one, and we humans who especially enjoy a treat of clam chowder, fresh shrimp or oysters on the half shell. The animal secreted calcium carbonate from the ocean to creat a protective shell, they can be beautiful and are used to adorn our homes in creative ways.  Scan_Pic0009

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Coral Sponge

March 28, 2014 by Fossillady
Florida Sponge Fossil
Florida Sponge Fossil Skeleton

The title, Coral Sponge, gives reference to the beautiful coral color of this sample and because I’m 99% certain it’s a sponge and not a coral fossil. The main reason is for the lack of vertical septa walls inside the cups, or in the case of sponges, inside the pores.

septa3
Coral cups showing septa walls lacking in sponges

There are some 5,000 to 10,00 known species of sponges and identification usually depends on the patterns and shapes of their spicules (tiny rods used for defense), usually only visible through a microscope in order to distinguish.

In lieu of this, I can only wager a guess as to its exact identity. It’s a rather attractive piece from my mother-in-law’s collection she gathered in the 70’s and 80’s off Florida beaches. So, I’m guessing it’s a type of calcareous type which forms a hard calcium carbonate skeleton; and I would also predict that it’s a tube type as well.

Below, I found an image of a tube type of sponge from a Florida reef. It looks fairly close in comparison.

Brown Cluster Tube Sponge Source:  http://reefguide.org/carib/pixhtml/brownclusteredtube1.html
Brown Cluster Tube Sponge Source

INTERESTING SPONGE FACTS

  • Sponges are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them.
  • Sponges do not have a nervous system, nor a digestive or circulatory systems; instead, they depend on a waterflow system to perform all the necessary functions.
  • For defense, sponges shed rod-like spicules forming a dense carpet several meters deep that keep away echinoderms (i.e. starfish) which prey on them. They also may produce toxins that prevent other prey from growing on or near them.
  • Their bodies have two outer layers, separated by a non-living gel layer which contains the tiny rod-like spicules.
  • Sponges are sessile (attached to a substrate or hard surface).
  • Most sponges live in quiet, clear waters environments to avoid sediment stirred up by waves or currents which would block their pores making it difficult for them to feed and breathe.
  • Sponges  improve water quality as effective biological filterers, extracting microscopic food and bacteria from the current.
  • Sponges evolved over 500 million years ago.
  • Sponges form different shapes, including tubes, fans, cups, cones, blobs, barrels, and crusts.

Sponge Classification

Kingdom: Animalia (animals)

Phylum: Porifera (Having Pores)

Four Classes

Demosponges – Largest class; Inner structure reinforced with collagen fibers and spine-like spicules made of silica minerals; Usually barrel shaped; Can live in a wide variety of habitats; Some are bath sponges

Hexactinellida – Glass Sponges; Spiny spicules made of silica minerals forming inner scaffolding structure with gelatin substance weaved in between framework; likes Polar Regions

Calcareous – Outer exoskeleton and inner spicules made of calcium carbonate. Restricted to shallow marine waters where production of calcium carbonate is easiest to obtain.

Scleropongiae (Coralline or Tropical Reef Sponges) soft body that covers a hard, often massive skeleton made of calcium carbonate, either aragonite or calcite.  The layered skeletons look similar to reef corals, therefore are also called coralline sponges.

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Maze Coral and Rose Coral Comparison

March 25, 2014 by Fossillady

Maze Coral

Maze Coral Source: http://en.wikipedia.org/wiki/Meandrina_meandrites
Maze Coral (Meandrina, meandrites) Living Sample
Source

Judging from the title of this article, you may have gathered their can be some confusion when identifying coral fossils and you would be right. All corals are not single organisms, but rather are a colony of individuals we know as polyps (the jelly-like part). The polyps band together and slowly build a calcium carbonate skeleton. Herein lies the physical diversity of corals as each species builds a slightly different style of skeleton.

I was confused by several coral species that I now feel confident about their identities after some head scratching and investigating. Maze Coral and Rose Coral fossil skeletons look very similar at first glance; descriptions below solves the puzzle.

Both species are commonly found in the Bahamas, Caribbean and Florida shores.

Rose Coral Fossil
Maze Coral Fossil (Meandrina, meandrites) Fossil Skeleton

While researching, I realized that maze corals are sometimes lumped together with brain corals, or are even called maze-brain corals.  The most distinguishing features from rose corals is that the maze-brain coral grow larger and display deeper ridges with well defined irregular plates less rounded than the rose coral. Also, there is an indentation running along the crest of the walls where the adjoining plates meet. Maze coral colonies form both flat heads and hemispherical (half-sphere) dome plates; colors tend to be brownish or greyish when live.

Maze Coral Habitat: Found in a wide range of habitats across the Caribbean, Gulf of Mexico, Bermuda, the Bahamas and Florida occurring at any depth less than 80 meters (260 feet) in reef-environments.

  • Maze Coral Classification
  • Kingdom: Animalia
  • Phylum: Cnidaria (Animal with stinging cells)
  • Class: Anthozoa (Flower like animals)
  • Subclass: Hexacorallia (polygonal corals having parts in multiples of 6)
  • Order: Scleractinia (Stony Skeleton)
  • Family: Meandrininidae (Meandering Colony Corals)
  • Genus: Meandrina (forms massive hemispherical heads or have large flat plates and can grow to one meter (3 feet) across)
  • Species: M. meandrites

Rose Coral

Rose Coral (Manicina, areolata) Skeleton

Rose Coral “Manicina, areolata” is a small stony coral often forming elliptical or oval colony heads with wide, winding valleys and rounded fleshy furrows; also, meandering valleys grow atop of smaller, shorter ridges. Colonies are often unattached to the seabed, living on sandy or seagrass bottoms.

Manicina areolata Source: coral.aim.gov.au
Rose Coral (Manicina, areolata) Living Sample
Source

Interesting Behavior

Rose corals are one of only a few corals that can be actively mobile. If a small colony of rose corals gets turned upside down, it proceeds to gorge its stomach with water in order to bloat, and then it jets the water out from one side at a time. This causes a back and forth rocking motion until the center of gravity shifts, allowing it to rapidly flip upright. The entire process takes a few hours until it finally flips over in an instant. 

Rose Coral (Manicina, areolata) Skeleton

Habitat: Rose coral “Manicina, aerolata” is very abundant off the Floridian shores as well as the Bahamas and Caribbean. It prefers shallow, productive, near shore habitats characterized by abundant sediments such as seagrass meadows, or along the fringes of mangrove forests. Larger colonies are more likely to die by smothering in the sediments placing a limit on the size any given colony can grow.

Colors: Yellowish-brown, tan or dark brown, often with the valleys and walls being contrasting colors. Like most corals, the polyps are only extended at night and are often green.

Manicina aerolata Source: http://reefguide.org/carib/rosecoral.html
Rose Coral (Manicina, aerolata) Living Sample
Source

ROSE CORAL CLASSIFICATION

  • Kingdom: Animalia
  • Phylum: Cnidaria (Animals with stinging cells)
  • Class: Anthozoa (Flower Animal)
  • Order: Scleractinia (Stony Skeleton)
  • Family: Faviidae (generally spherical shape and grooved surface which resembles a brain)
    Genus: Manicina
  • Species: M. areolata

Note: The genus, Manicina, includes over 10 species, but Manicina, areolata is the only species that survives today. The heyday for Manicina was during the Miocene and Pliocene epochs between (24 million to 1.6 million years ago). About one million years ago, approximately half the species of reef corals living in the Caribbean became extinct.

Both Maze Coral and Rose Coral are considered threatened species, though their specific status and risk factors differ.

For more interesting facts, photos and identification of Florida, Gulf and Atlantic Coast Corals to “Categories” sidebar under “Corals, Forida, Atlantic and Gulf Coasts”

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Low Relief Lettuce Coral

March 23, 2014 by Fossillady
Low Relief Lettuce Coral Fossil (Agaricia, humilis)
Low Relief Lettuce Coral Skeleton (Agaricia, humilis)

Low relief lettuce coral is fairly common with a widespread distribution in the open seas of the Caribbean, Bahamas and Florida, often scattered among other corals within inner bays and sometimes within mangrove roots. It can thrive from shallow sea levels to the lower depth limits of the reef, approximately 60 meters (200 feet) deep. It displays a number of growth forms, such as appearing saucer-like on cliff sides or small half-moon shaped in shallow depths. In depths deeper than 10  meters (3 feet), the coral forms broad vertical scales with corallites on one side only.

Low Relief Lettuce Coral
Low Relief Lettuce Coral (Agaricia, humilis) Living Sample
Source

CLASSIFICATION:

  • Kingdom: Animalia
  • Phylum: Cnidardia (C is silent) Marine group with stinging cells
  • Class: Anthozoa – Flower Animal
  • Order: Scleratinia – Reef building stony corals
  • Family: Agariciidae – includes cactus corals, elephant skin corals, plate corals and lettuce corals. Members of the family include symbiotic algae called Zooxanthellae in their tissues which help provide their energy
  • Genus: Agaricia – lettuce corals
  • Species: humilis – low relief
Winkie, Joe, Johnny and Joey
Winkie, Joe, Johnny and Joey, 1950’s

 

As I have mentioned in other coral posts, my mother in law, Winifred (Winkie) loved collecting coral during Florida vacations in the 60’s and 70’s. My late husband, Joseph III, came from a hard working family in the 50’s living in Detroit. His dad, Joseph II, was a designer for Chrysler Corporation and designed an amphibious vehicle used in WWII.    

I feel honored to have samples from her coral collection and am excited to share them with you. She would have been thrilled by this.  

.

For more interesting facts, photos and identification of Florida and Atlantic Coast Corals scroll to sidebar “Categories” under “Corals Florida, Atlantic and Gulf Coasts”.

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Cactus Coral Pavona

March 21, 2014 by Fossillady
Coral Skeleton Shows Closely Spaced Polyps of the “Cactus Coral (Pavona)“

After much digging around I finally identified this amazing specimen as a Cactus Coral from the genus of Pavona. The small prickly pattern of polyp corallites was the best defining feature, as well as the folding plates that loosely resemble a cactus.

Cactus Coral Pavona
Cactus Coral (Pavona) Living Sample
Source

The Pavona, Cactus Coral is a small-polyp, stony coral which has been called, Cactus, Potato Chip, or Lettuce Coral.  A single species may vary in form according to the currents, wave action, lighting conditions and depth of its location. They can also vary in color from shades of light and dark brown to green with cream or white margins. Some have a fluorescent glow that can be seen beneath the polyps, giving these corals an interesting look. They are known to make a popular addition to the home aquarium.

Cactus Coral Pavona Source: "Douglas Illistration":http://www.freewebs.com/douglasillustration/reeftank.htm
Cactus Coral (Pavona) Living Sample
Source

CACTUS CORAL CLASSIFICATION

Kingdom: Animalia
Phylum: Cnidardia (A group containing over 10,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey by shooting off a threadlike, often toxic, tubule from inside the cnidocyst.)
Class: Anthozoa (Flower Animal)
Order: Scleratinia (Stony corals which are marine corals that generate a hard skeleton. They first appeared in the Middle Triassic and descended from the tabulate and rugose corals that barely survived the end of the Permian. Much of the framework of today’s coral reefs is formed by scleractinians. Stony coral numbers are expected to decline due to the effects of global warning and increased acidity due to pollution.)
Family: Agariciidae (Reef building stony corals including cactus corals, elephant skin corals, plate corals and lettuce corals.)
Genus: Pavona (Coral colonies of this type have vertical, irregular, two-sided fronds.)
Species: Possibly minuta or duerdeni

For more interesting facts, photos and identification of Florida and Atlantic Coast Corals Scroll Here if you’re not already viewing this post under “Coral Florida” in the Categories list.

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Boulder Brain Coral and Symmetrical Brain Coral Compared

March 19, 2014 by Fossillady

I have two species of coral from my collection that have earned the common name, Brain Corals, due to their convoluted surfaces, loosely resembling the physical brain and general spherical formations. Both species are slow growing, colony forms which may reach colossal sizes to a few meters in length and live for hundreds of years. The oldest know brain coral is 900 years old. Both species below grow in shallow parts of the Caribbean Sea, the Bahamas, Bermuda, Texas and Florida.

Boulder Brain Coral (Colpophyllia, natans) Skeleton

Boulder Brain Coral (Colpophyllia, natans) is a very large brain coral diplaying domed, hemispherical colonies that may exceed one meter (3 feet) across, but smaller colonies may be flat discs depending on location. 

Large Brain Coral Boulder Skeleton – 14 iches across (35 cm)

Boulder Brain Coral polyp valleys on the surface may stretch the entire width, or be subdivided into shorter series. The valleys and walls may be two centimeters broad distinguishing it from my Symmetrical Brain Coral (shown below) which display narrower valleys and walls.The walls of the Boulder Brain Coral commonly have fine grooves running along the raised walls. The Boulder Brain Coral also has a sharp break between the wall and the valley floor. The living Boulder Brain Coral colors vary with ridges being various shades of brown, and the valleys are varied colors from whitish, green, or tan.

OLYMPUS DIGITAL CAMERA
Boulder Brain Coral (Colpophyllia, natans) Living Sample Source

Symmetrical Brain Coral

HPIM1075
Symmetrical Brain Coral (Diploria, strigosa) Skeleton

Symmetrical Brain Coral (Diploria, strigosa) forms flat plates or massive hemispherical domes up to 2 meters, (6 feet) in diameters. Sometimes, they will show a very narrow groove along the tops of the walls, which have sloping or rounded sides. Valleys may run straight for considerable distances or be highly irregular in direction. Living samples  range in color from purplish brown to tan, grey or green, often with the groove floors being a contrasting paler color.

Diploria, strigosa is the most widespread of all the Diploria species, being more resistant to threats with the ability to thrive in muddy stretches of seabed where many other corals are not able to flourish needing clearer waters.

Symmetrical Brain Coral (Diploria, strigosa) Source: http://reefguide.org/carib/pixhtml/symmetricalbrain2.html
Symmetrical Brain Coral (Diploria, strigosa) Living Sample
Brain Corals Habitat  Source: http://www.dcbiodata.net/explorer/results/detail/5260
Brain Coral Habitat

NOTE ABOUT SCLERACTINIA: The order “Scleractinia” includes all living corals today developing a stony, light porous skeleton. Scleractinians were fairly rare in North America until the Cretaceous, about 100 million years ago, when they first built reefs in Texas and Mexico. It wasn’t until the Pleistocene Period, about 2.6 million years ago, that reefs flourished widely where they do today.

Brain Coral Open Polyps At Night
Brain Coral Open Polyps At Night

Night Time Activity : Coral polyps, the living breathing jelly-like part of the animal, are found in single file in the valleys of this brain coral’s convoluted ridges. They are normally contracted during daylight expanding at night to catch micro-bits of food drifting by.

BRAIN CORAL CLASSIFICATION

  • Kingdom  –  Animalia
  • Phylum  –    Cnidaria (means stinging cells)
  • Class  –     Anthozoa (means flower animal)
  • Order  –  Scleratinia (stony skeleton)
  • Family  –  Faviidae (spherical group with grooved surfaces)
  • Genus  –   Colpophyllia (large-grooved) / Diploria (grooved)
  • Species – strigosa (thin, narrow, well-defined ridges) / natans

For more interesting facts, photos and identification of Florida, Gulf and Atlantic Coast Corals scroll to “Categories” sidebar under “Corals Florida, Atlantic and Gulf Coasts.

© 2026 Fossillady

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