Giant Jurassic Kranaosphinctes Ammonite Fossil - Perfect...

Monumental fossil specimen from the Morondava basin — The lot features an extraordinary fossil specimen of Kranaosphinctes rabei, a genus of ammonite belonging to the Perisphinctidae family. This impressive find dates to the Late Jurassic, more precisely the Oxfordian (about 161-156 million years ago), and represents tangible evidence of the richness of prehistoric marine life. The precise taxonomic identification, with the broad evolved shell and marked radial ribs, is consistent with the diagnostic characteristics of Kranaosphinctes rabei, a notable representative of Mesozoic invertebrate megafauna. Visually, the ammonite exhibits remarkable preservation of its primary morphological structures. The inner whorl is well defined, with progressive whorls culminating in a majestic circumference. The primary and secondary ribs, typical of the species, are visible along the shell, giving the fossil a sculptural texture. The outer surface of the shell is characterized by a vibrant color combination, alternating light ivory and cream tones, derived from calcite fill, with deep shades of red oxide, rusty brown, and terracotta, which enrich its visual profile. The intense and varied coloration of the fossil is the result of a long diagenetic and mineralization process. During fossilization in the marine sediments of the Morondava basin, in Madagascar, iron oxides permeated the original shell tissues, replacing or impregnating the calcitic material and conferring the specimen its distinctive ferruginous patina. This process not only contributed to the exceptional preservation of the fossil but also generated a color palette of great aesthetic impact, making it a unique piece. The origin of this specimen is the Morondava basin, in southwestern Madagascar, specifically in the Sakaraha area, Atsimo-Andrefana region. This locality is world-renowned for its abundance and quality of Jurassic ammonite fossils, offering an invaluable window into the marine ecosystems of that era. The certified provenance adds significant scientific and historical value to the specimen, as it contextualizes its geological and biological formation. With a weight of 17,600 grams and imposing dimensions (410 x 360 x 145 mm), this Kranaosphinctes rabei fossil qualifies as a museum piece. Its structural integrity and the aesthetics arising from mineralization make it an object of very high collectible value. Despite its geological age, the piece presents itself in excellent natural condition, with minimal alterations that attest to a carefully carried out extraction and preservation process. Its presence in a collection is a statement of prestige and deep paleontological interest, capable of capturing attention in any display setting, from a cabinet of curiosities to more formal contexts.

Estimate:£2,281.26

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