Researchers report a marine ammonite preserved in Burmese amber. Because the source of amber is fossilized tree resin, the inclusion of aquatic and marine animals in amber is exceptionally rare. Bo Wang, David Dilcher, and colleagues describe the terrestrial and marine animal assemblage present in a specimen of Burmese amber from Myanmar. Prominent in the amber is a marine ammonite shell, identified by its shell structure as a juvenile from the Late Albian or Early Cenomanian age of the Cretaceous Period. Accompanying the ammonite are marine gastropods and terrestrial mites, spiders, other insect orders, and millipedes. Several lines of evidence suggest that the ammonite and the gastropods were dead before becoming engulfed in resin. No soft tissue was preserved in the marine species, which displayed signs of abrasion, and the ammonite contained coarse sand in its shell. Taken together, the evidence suggests that the amber was formed on a beach with resin-producing trees close enough to the water to capture both terrestrial insects on the tree and remains of marine organisms transported into the resin, which was later preserved and fossilized. Previously discovered Burmese amber samples lacked ammonites. Hence, the authors suggest, the presence of a rare specimen in amber warrants exploration of the possibly exceptional circumstances of its fossilization.
Article #18-21292: "An ammonite trapped in Burmese amber," by Tingting Yu et al.
MEDIA CONTACTS: Bo Wang, Chinese Academy of Sciences, Nanjing, CHINA; tel: 0086-13951982860; e-mail: bowang@nigpas.ac.cn ; David Dilcher, Indiana University, Bloomington, IN; tel: 734-239-5248; e-mail: dilcher@indiana.edu
###
Proceedings of the National Academy of Sciences