The suture line was of an ammonite type, relatively uncomplicated and jagged. The adult stage (over 7 cm in diameter) was multi-tuberculosis (distinguished by the appearance of new tubercles, more or less numerous depending on the species), while the senile (or gerontico) stage was characterized by the disappearance of the tubercles and by an ornamentation with simple ribs, which finally tended to disappear in the most long-lived specimens, with the last round almost smooth. The size of the shell, on average, was between 5 and 10 centimeters in diameter, although in some species it could exceed twenty centimeters in diameter in the most developed specimens.Īt the beginning of development (up to about 2 cm in diameter) it had no ribs, with only two rows of tubercles subsequently (up to about 7 cm of diameter) another tubercle appeared in a lateral position, and the coasts developed. The presence of the tubercles gives the lap section a typical polygonal pattern. These coasts brought more or less numerous tubercles that, in the animal alive, were surmounted by long thorns, sometimes partly preserved in the best preserved fossil specimens. The ornamentation consisted of simple but very robust coasts. The shell of this ammonite was symmetrical, with a flat spiral, with a poor covering of the subsequent turns, of a vaguely globular appearance.

He lived at the end of the Lower Cretaceous (Albian, about 105 million years ago) and his fossil remains were found all over the world, mainly in Europe and the Near East. Dropdown echinoderms (sea-urchins, star-fishes, crinoids)įossil Ammonite Douvilleiceras orbignyi 'Goat Horn' cm 3.8 x 3 x 2 - gr 29.5.ĭouvilleiceras is an extinct cephalopod mollusc belonging to the Ammonites.Dropdown insects (spiders, bugs, bees, locusts).Dropdown trilobites crostaceous (crabs, crayfish).Dropdown trilobites and other invertebrates.Dropdown Cingulata and Pilosa (armadillos, sloth).Dropdown rodents (capybara mouses hares beavers).Dropdown cetaceans and sirenia (whales and manatees).Dropdown artiodactyls (cattle, pigs, deer, camels, antelopes).Dropdown Perissodactyla (horses, rhinos, tapirs).Dropdown Proboscidea (mammoth and elephants).Dropdown pterosaurs dimetrodon and other reptiles.Dropdown ichthyosaurs plesiosaurs notosaurs.Dropdown dinosaurs (saurischian ornithischian).Dropdown Ensifera (crickets, grasshoppers).Dropdown false butterflies fridge magnets.Dropdown strange and giant spectacular insects.Dropdown raw minerals, rocks and crystals.

Dropdown springs necklaces parures earrings bracelets.Dropdown large size tumbled stone pendants.Dropdown costume jewelry tumbled stones.Dropdown moqui abalone Apache tears shiva lingam.If it were complete, this ammonite's total diameter could have been from 2.5-3.5 metres. The largest specimen found is 1.8 metres in diameter but is also incomplete. The largest known species of ammonite is Parapuzosia seppenradensis from the Late Cretaceous. Zoë says, 'Ammonites were quite diverse and evolved rapidly, so if you sample stratigraphically through rocks, you can actually see the evolution and the changes through them.' How big were ammonites?Īmmonites came in a range of sizes, from just a few millimetres to times bigger, with larger sizes more common from the Late Jurassic onwards. However, it is estimated that over 10,000 species of ammonite - possibly even over 20,000- have been discovered. But when ammonite fossils that looked unique were found in the past, they tended to be recorded as new species instead of as the microconch (male) or macroconch (female) of an existing species, as this difference between the sexes was not yet known about. Like modern cephalopods, ammonites displayed sexual dimorphism, which is the noticeable difference in appearance between sexes. But figuring out exactly how many species have been found so far is a bit tricky.

Ammonite fossil meaning