Ammonites

MedievalRocker
recent  |  interesting  |  random  |  favorites  |  contacts  |  sets  |  tags:  
Ammonites
Ammonites

A couple of Ammonites that I have been recently given , a fascinating creature from many many years ago now . The reverse side is also interesting as it often has a mother of pearl pearlescence on it !
Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family Nautilidae).The earliest ammonoids appeared during the Emsian stage of the Early Devonian, with the last species vanishing during or soon after the Cretaceous–Paleogene extinction event. 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.

Ammonoids exhibited considerable diversity over their evolutionary history, with over 10,000 species having been described . Ammonoids are excellent index fossils, and they have been frequently used to link rock layers in which a particular species or genus is found to specific geologic time periods. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found, primarily during the Cretaceous period.

The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder (d. 79 AD near Pompeii) called fossils of these animals ammonis cornua ("horns of Ammon") because the Egyptian god Ammon (Amun) was typically depicted wearing rams' horns. Often, the name of an ammonite genus ends in -ceras, which is from ancient Greek κέρας (kéras) meaning "horn".

© All Rights Reserved
Taken on: February 27, 2025
Tags: Everybody's photos tagged with ammonite ammonite Everybody's photos tagged with ammononoids ammononoids
Sets appears in:   • OddShots    • Been Exploring    more » • history    • Nature & Landscape    • Something to think about    « less
Groups appears in:   • History is All Around Us    • UK amateur photographers    more » • [][][]100%PERFECT[][][]    • SIGMA 105mm F2.8 EX DG OS HSM Macro    • in explore    • New Ipernity Survivors    • ♣My Hat's Off to You!!    • Amateur Photographer Magazine    • flickr world wide    • 99+ Faves Photo Group    • #1 Images that caught my eye    • Ipernity Survivors    • Canon EOS 77D User    • Interesting Nature    • Flickr Photo Album Unlimited & Instant Posting    • Canon EOS 77D Unlimited (no 30/60 limit)    • Paint a Picture    • Show your EXIF    • WONDERS OF PHOTOGRAPHY IN GENERAL.MARAVILLAS DE LA FOTOGRAFIA EN    • Immagini : stimolo, sogno, illuminazione    • Sigma 105mm f/2.8 EX DG OS HSM, world wide    • 👍Mundo y vida    « less
Camera: Canon EOS 77D, f/8.0, 1/13 sec, 105mm, ISO 200 (more info) (hide info)
Camera: Canon EOS 77D
Aperture: f/8.0
Exposure Time: 0.077 sec (1/13)
Focal Length: 105mm
ISO: 200
Exposure Bias: -2/3 EV
Flash: Off, Did not fire
Exposure Program: Aperture-priority AE
Exposure Mode: Auto
Metering Mode: Multi-segment
White Balance: Manual
Color Space: sRGB
Show full info
Stats: 6,029 views / 41 comments