An ammonite trapped in Burmese amber.

Area of Science:

• Paleontology
• Geology
• Paleoecology

Background:

• Amber, fossilized tree resin, typically preserves terrestrial organisms.
• Marine fossils are exceedingly rare in Cretaceous and Cenozoic amber deposits.
• Previous amber research has focused primarily on terrestrial inclusions.

Purpose of the Study:

• To report the discovery of a marine ammonite and associated organisms within mid-Cretaceous Burmese amber.
• To analyze the taphonomy and paleoecology of this unique amber inclusion assemblage.
• To utilize advanced imaging techniques for detailed study of fossilized specimens.

Main Methods:

• X-ray-microcomputed tomography (CT) for high-resolution 3D imaging of inclusions.
• Detailed morphological analysis of the ammonite and associated arthropods.
• Stratigraphic and paleoecological interpretation of the amber deposit and its contents.

Main Results:

• Discovery of a juvenile ammonite (Puzosia (Bhimaites)) and marine gastropods in Burmese amber.
• Identification of a diverse assemblage of terrestrial arthropods (over 40 individuals) alongside marine life.
• Evidence suggests the ammonite and gastropods were abraded on a seashore before resin entrapment.
• The find supports a Late Albian-Early Cenomanian age for the amber.

Conclusions:

• This is the first reported occurrence of an ammonite in Cretaceous amber.
• The findings provide crucial insights into the taphonomy of amber formation, particularly resin interaction with coastal environments.
• The study highlights the complex paleoecology of Cretaceous amber forests adjacent to marine settings.