Identify Your Specimens Here - Fossils, Minerals & Gemstones
Slugs and snails, abalones, limpets, cowries, conches, top shells, whelks, and sea slugs are all gastropods. The gastropods are in origin sea-floor predators, though they did evolve into many other habitats. Many lines living today evolved in the Mesozoic era, taking advantage of the huge supply of food on the sea floor.
The class has two living subclasses. In the Coleoidea, the mollusc shell has become smaller, or is not there at all; this subclass has the octopus, squid, and cuttlefish. The Nautiloidea have a shell; Nautilus is its only living genus.
There are at least 800 different living species of Cephalopods. Two important extinct taxa are the Ammonites, and the Belemnites (order Belemnoidea, of class Coleoidea). Cephalopods are found in all the oceans of the world and at all pelagic levels. None of them can live in freshwater (water with no salt in it), but a few species live in brackish (partly salty) water.
At their peak in the Palaeozoic era the brachiopods were among the most abundant filter-feeders and reef-builders, and occupied other ecological niches, including swimming in the jet-propulsion style of scallops. Brachiopod fossils have been useful indicators of climate changes during the Paleozoic era.
They do look rather like bivalves, but their internal organisation is quite different. Their mostly calcium carbonate shells or "valves" have upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end. The front can be opened for feeding or closed for protection.
Two major groups are recognized, articulate and inarticulate. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system of muscles used to fit the two halves together. In a typical brachiopod a stalk-like pedicle projects from an opening in one of the valves (the pedicle valve). Its function is to attach the animal to the seabed but clear of silt that would obstruct the opening.
Brachiopods have a huge fossil record going back to the Cambrian. They were much reduced by the two main extinction events, the P/Tr and K/T. Bivalve molluscs took over their inshore habitats in the Mesozoic, and since then the brachiopods have been confined to deeper water, except for a handful of species. There are about 100 to 350 species living; the fossil species number 12,000.
All crinoids are marine, and live both in shallow water and in depths as great as 6000 meters. The basic echinoderm pattern of fivefold symmetry can be recognized, but most crinoids have many more than five arms. Crinoids have a mouth on the top surface that is surrounded by feeding arms.
The crinoids have a long history. They were the first echinoderms to appear in the fossil record, and have kept their early structure throughout their long career. They were extremely common in the Palaeozoic, and some rocks from the Carboniferous consist almost entirely of fossil crinoids.
Nautiloids flourished during the early Palaeozoic era, when they were the main predatory animals. They developed an extraordinary ramge of shell shapes and forms. Some 2,500 species of fossil nautiloids are known, though only a few species survive today.
Together, many zooids form colonies, many colonies form reefs. Coral reefs can be massive structures, stretching hundreds of miles. The Great Barrier Reef in northern Australia can be seen from space.
The oldest coral fossils are over 500 million years old. The earliest forms were different from those we see today and they died out 225 million years ago. Modern corals are still common in tropical oceans.
In some formations, shark's teeth are a common fossil. These fossils can be analyzed for information on shark evolution and biology; they are often the only part of the shark to be fossilized. Fossil teeth comprise much of the fossil record of the Elasmobranchii, extending back to hundreds of millions of years. Shark teeth are also useful in conducting research about the structure of teeth, shark migration patterns, and identifying shark species.
The most ancient types of sharks date back to 450 million years ago, during the Late Ordovician period, and are mostly known by their fossilised teeth. However, the most commonly found fossil shark teeth are from the Cenozoic era (the last 66 million years).
Ammonites lived during the periods of Earth history known as the Jurassic and Cretaceous. They became extinct at the end of the Cretaceous Period at roughly the same time as the dinosaurs disappeared. Ammonites were marine animals and had a coiled external shell similar to the modern pearly nautilus.
Fossil White Cephalopods
Cephalopods have a very long history of life on Earth (at least 550 million years). They first appear as fossils in rocks of earliest Cambrian age, and their descendants survive, albeit relatively rarely, in today's oceans and seas. They were particularly abundant during the Palaeozoic Era (248 to 545 million years ago), and are often the most common fossils in rock of that age.
Fossil Clams Brachiopod
Bivalves have inhabited the Earth for over 500 million years. They first appeared in the Middle Cambrian, about 300 million years before the dinosaurs. They flourished in the Mesozoic and Cainozoic eras, and abound in modern seas and oceans; their shells litter beaches across the globe.
Because many crinoids resemble flowers, with their cluster of waving arms atop a long stem, they are sometimes called sea lilies. But crinoids are not plants. Like their relatives--starfishes, sea urchins, sea cucumbers, and brittle stars--crinoids are echinoderms, animals with rough, spiny surfaces and a special kind of radial symmetry based on five or multiples of five.
Crinoids have lived in the world's oceans since at least the beginning of the Ordovician Period, roughly 490 million years ago.
Fossil Dinosaur Bone
Utah, over 65 Million Years Old
• Dinosaur fossils have been found on every continent of Earth, including Antarctica.
• Fossils help us understand what the dinosaurs were like. Information can be gathered from sources such as fossilized bones, footprints, stomach stones, feces, internal organs, soft tissues, eggs and feathers.
• Over 1000 different species of dinosaurs have been named and the list continues to grow as new fossils are discovered.
• Some of the largest fossilized dinosaur eggs ever discovered were found in China in the mid 1990’s. The eggs are over 60cm (2ft) long and 20cm (8in) wide.
Fossil (Orthoceras) Sea Squid - Morocco - Ordivician Period (300 million Years Old)
Ancient Mollusk, The Orthoceras. ... Orthoceras was an ancient mollusk that lived more than 300 million years ago. The name means straight horn, referring to the characteristic long, straight, conical shell. The preserved shell is all that remains of this ancestor of our modern-day squid.
Corals are simple animals that secrete skeletons made of calcium carbonate. They are close relatives of sea anemones and jellyfish and are the main reef builders in modern oceans. Corals can be either colonial or solitary.
As fossils, corals are found worldwide in sedimentary rocks. Based on these fossils, we know that the corals began their long evolutionary history in the Middle Cambrian, over 510 million years ago. In Kansas, they are fairly common in Pennsylvanian and Permian rocks, deposited from about 315 to 250 million years ago.
Fossil Shark Teeth - Morocco - Sand Tiger Shark - over 33 Million Years Old (Eocene Period)
A shark tooth is one of the numerous teeth of a shark. A shark tooth contains resistant calcium phosphate materials. Sharks continually shed their teeth; some sharks shed approximately 35,000 teeth in a lifetime, as well as replace them by producing thousands of more. There are four basic types of shark teeth: dense flattened, needle-like, pointed lower with triangular upper, and non-functional. The type of tooth that a shark has depends on its diet and feeding habits.
POLISHED AGATES FROM BRAZIL
Amethyst is a purple variety of quartz (SiO2) and owes its violet color to irradiation, iron impurities
Watermelon Tourmaline Gemstone