Giant Ammonite | Lobolytoceras costellatum | Madagascar

Lobolytoceras costellatum
Late Jurassic, Oxfordian Stage (161-154 million years old)
Sakaraha, Madagascar

Specimen approx. size: 34" x 28" x 12"

Specimen on stand approx. size: 34" x 32" x 28"

Custom mobile stand included.

*Specimen weighs at least 300 lbs. Please use utmost caution when moving it.*

*Due to the size and weight of this specimen, it will be shipped in an internationally compliant wooden crate.

Shipping costs will be calculated and billed after purchase. Please contact us if you need a specific shipping rate prior to purchase. You may opt in for in-store pickup to cut your shipping costs all together and pick up your specimen in person. You can pick up from our store location in Kemmerer, Wyoming, or we deliver to both the Denver Gem & Mineral show in the Fall and the Tucson Gem & Mineral show in the winter. For any questions, please don't hesitate to contact us directly.

This striking ammonite has been expertly polished to reveal its intricate suture pattern. Beautifull preserved all around, this massive ammonite would make a commanding addition to any fossil collection.

Lobolytoceras costellatum is an extinct species of ammonite, a marine cephalopod, that lived during the Jurassic Period. This species is notable for reaching exceptionally large sizes, with specimens over 24 inches (60 cm) in diameter. Its shell is typically planispirally coiled, with a rounded to moderately compressed whorl profile and prominent radial ribs (costae) across the shell.

The shell shows the characteristic ammonite suture pattern, where the internal partitions (septa) met the outer shell wall. These intricate sutures helped strengthen the shell and are often particularly visible on well-preserved specimens.