This Specimen has been sold.
Unusual Desmoceras Ammonite Split Pair
The vast majority of larger size split ammonite pairs from Madagascar are of the genus Cleoniceras. This pair is of the genus Desmoceras, with the distinctive D shaped sutures. Each half of the pair is 4.25 inches wide, has many crystal lined cavities and the reverse side displays the "mother-of-pearl" looking shell. They display very nicely on the included stands.
Ammonites were predatory mollusks that resembled a squid with a shell. These cephalopods had eyes, tentacles, and spiral shells. They are more closely related to a living octopus, though the shells resemble that of a nautilus. Ammonites appeared in the fossil record about 240 million years ago and they barely survived several major extinction events. The last lineages disappeared 65 million years ago at the end of the Cretaceous.