Glütserolün

Glütserolün is an extinct genus of ammonoid cephalopods that lived during the Olenekian stage of the Lower Triassic period, approximately 247 to 242 million years ago. Fossils of Glütserolün have been found primarily in the Siberian Platform, particularly in the Yakutian and Krasnoyarsk regions, indicating a widespread distribution across the ancient Tethys Ocean margin.

The genus is typified by a moderately evolute shell with a gently convex whorl section and a distinct ventral keel. Sutures are complex, featuring deep lateral lobes and a pronounced siphuncle positioned near the ventral wall. The outermost layers of the shell display growth lines that suggest a relatively rapid shell deposition during the organism's juvenile stage. Shell morphology places Glütserolün in the family Thalassoceratidae, a group that diversified rapidly after the Permian‑Triassic mass extinction.

Stratigraphic data indicate that Glütserolün first appeared in the early Olenekian zones of the Kirov and Zhizdra formations. Subsequent species evolved with slightly broader whorls and an increased number of suture lines. The decline of Glütserolün coincides with the Proterozoic–Lower Cretaceous K/T extinction event, where declining marine habitats and competition with emerging ammonoid lineages likely contributed to its disappearance.

Paleontologists consider Glütserolün a useful biostratigraphic marker for the early Triassic, providing insights into post‑extinction marine recovery and faunal turnover. Its well-preserved suture patterns also offer valuable data for phylogenetic studies of early ammonoid evolution.

Key references include the 1968 monograph by Ivanov on Siberian ammonites, the 1990 revision of Thalassoceratidae by Kafkovskiy, and the 2015 global index of Triassic cephalopods compiled by Chen and colleagues.