Exquisitely preserved Jurassic Perisphinctes ammonite...

Upper Jurassic Period (Oxfordian-Kimmeridgian) — This exceptional paleontological specimen presents a natural aggregation of ammonites of the Perisphinctes genus, magnificently preserved within a compact matrix. The original crystalline formation of the shells has been replaced by calcite, allowing detailed fossilization of these marine cephalopods. The absence of signs of assembly confirms the geological integrity and in-situ origin of this lot. The ammonites display the characteristic planispiral morphology, with symmetric whorls and clear visibility of radial ribbing. The sutures, particularly fine and regular, bifurcate gracefully toward the periphery of the shell, a crucial distinctive trait for identifying the genus Perisphinctes. The external surface exhibits a color ranging from golden beige to light brown, with slight mineral iridescences attest the post-mortem calcitic recrystallization. Provenance is clearly identified in the fossiliferous beds of Sakaraha, in southwestern Madagascar, a geological locality renowned for its extraordinary preservation and the abundance of Upper Jurassic specimens. This geological context provides valuable information on the marine environmental conditions about 150 million years ago, characterized by warm, life-rich waters. The piece’s aesthetics are remarkable, with several Perisphinctes individuals of various sizes harmoniously integrated into the matrix, creating a natural sculptural composition. The three-dimensionality and density of the specimens make this lot a focal point for any collection. It is mounted on a discreet black metal base, which facilitates display and highlights its verticality. The state of preservation is excellent, with well-preserved morphological details that allow in-depth study of the paleobiology of these organisms. No significant signs of post-depositional damage or alteration are evident that would compromise the structural or aesthetic integrity of the specimens. The matrix provides excellent contrast with the lighter tones of the fossils. From a collecting standpoint, this Perisphinctes aggregation from Sakaraha represents a specimen of notable value. Its uniqueness as a natural, non-assembled formation, the specific provenance, and the quality of preservation make it a desirable piece for both amateur paleontologists and seasoned collectors of Jurassic fossils. It stands out from single specimens for its complexity and visual impact.

估價:$201.91

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