Information om | Engelska ordet AMMONITES

Exempel på hur man kan använda AMMONITES i en mening

• These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land.
• They are often called ammonites, which is most frequently used for members of the order Ammonitida, the only remaining group of ammonoids from the Jurassic up until their extinction.
• He explored pits and quarries in the surrounding areas, discovering ammonites, shells of sea urchins, fish bones, coral, and worn-out remains of dead animals.
• The Catalan Bay Shale Formation contains unidentifiable echinoid spines and belemnite fragments and infrequent Early Jurassic (Middle Lias) ammonites.
• Within these beds are found abundant marine fossils (ammonites and skeletons of fish and such marine reptiles as mosasaurs, plesiosaurs, and extinct species of sea turtles) along with rare dinosaur and bird remains.
• In 1845, he devised a trinomial system of nomenclature for Jurassic ammonites, which has caused some difficulty for later taxonomists.
• Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and Spirula.
• Shasta County had captured attention from California Paleontologists in 1893 after James Perrin Smith (of Stanford) searched for ammonites.
• The symbol of the college is the ammonite of St Hilda and during the centenary, 100 silver ammonites were created; now proudly owned by alumnae of the college in honour of St.
• The genus is almost certainly paraphyletic but remains in wide use as a "catch all" for heteromorph ammonites of the superfamily Turrilitoidea that do not neatly fit into the more derived groupings.
• The shell is always planispirally coiled, unlike those of Mesozoic ammonites in which some are trochoidal and even aberrant (called heteromorphs).
• The earliest are local fossils including ammonites and a display about the discovery of an ichthyosaurus at Alford.
• Gault yields abundant marine fossils, including ammonites (such as Hoplites, Hamites, Euhoplites, Anahoplites, and Dimorphoplites), belemnites (such as Neohibolites), bivalves (such as Birostrina and Pectinucula), gastropods (such as Anchura), solitary corals, fish remains (including shark teeth), scattered crinoid remains, and crustaceans (such as the crab Notopocorystes).
• Fossilised ammonites and belemnites can often be found on the beach due to continued coastal erosion of the soft blue lias clays which make up the cliffs.
• As with other ammonites, the shell consisted of a series of camerae, or chambers, that were connected to the animal by a narrow tube called a siphuncle by which gas content and thereby buoyancy could be regulated in the same manner as Nautilus does today.
• These irregularly-coiled ammonites are called heteromorph ammonites, in contrast to regularly coiled ammonites, which are called homomorph ammonites.
• The limestones date from the Visean period (Lower Carboniferous), formed as sediments in a tropical sea about 350 million years ago, and compressed into horizontal strata with fossil corals, crinoids, sea urchins, and ammonites.
• Biostratigraphically, the first appearance of psiloceratid ammonites has been used; but this depends on relatively complete ammonite faunas being present, a problem that makes correlation between sections in different parts of the world difficult.

Förberedelsen av sidan tog: 146,30 ms.