Fly in amber (Amber Formation, Middle Eocene; Yantarnyi, Samland Peninsula along the Baltic Sea, far-western Russia) 1
Fossil fly in Baltic amber from the Eocene of Russia. (polished; 16 millimeters across)
Biogenic products are objects produced by ancient organisms. Many paleontologists refer to these as trace fossils, but they really aren't. Examples of fossil biogenic products include eggs, amber (fossilized tree sap), coprolites (fossilized feces), and spider silk.
Fossils in amber are some of the most intriguing remains of ancient organisms anywhere in the rock record. Amber is fossilized tree sap (resin). Fossilized tree resin is technically called resinite. This piece of amber comes from the Baltics. Baltic amber is some of the most famous on Earth. Amber specimens from different localities are often given different varietal names. Baltic amber is a type of resinite often called succinite. Some amber specimens have body fossil inclusions, and others don't. The amber itself is a biogenic product, not a body fossil.
The Baltic amber shown here has a nice fossil inclusion. This insect is a fly (Animalia, Arthropoda, Insecta, Diptera, Brachycera). Note that this fossil fly is covered in a whitish milky material. That is a decay coating. This is commonly encountered in Baltic amber, and is one diagnostic method of identifying genuine succinite (there’s lots of fake amber fossils out there). This amber specimen also has lots of minute, stellate trichomes (not visible in photo) that are also unfakeable (I think). They are “down” - epidermal hairs on flowers & leaf buds from ancient oak trees. These are abundantly preserved in genuine Baltic amber.
Stratigraphy: “Blue Earth layer”, “Amber Formation”, Lutetian Stage, lower Middle Eocene
Locality: Yantarnyi, coastal western Samland Peninsula, western Kaliningrad District, Baltic Sea, far-western Russia
Some references on amber & fossils in amber:
Poinar, G. & R. Poinar. 1994. The Quest for Life in Amber. Reading, Massachusetts. Addison-Wesley Publishing Company. 219 pp.
Dahlström, A., L. Brost & J. Leijonhufvud. 1996. The Amber Book. Tuscon, Arizona. Geoscience Press, Inc. 134 pp.
Grimaldi, D.A. 1996. Amber, Window to the Past. New York. American Museum of Natural History. 215 pp.
Ross, A. 1998. Amber. London. The Natural History Museum. 73 pp.
Poinar, G.O. & R. Milki. 2001. Lebanese Amber, the Oldest Insect Ecosystem in Fossilized Resin. Corvallis, Oregon. Oregon State University Press. 96 pp.
Geirnaert, E. 2002. L'Ambre, Miel de Fortune et Mémoire de Vie. Monistrol-sur-Loire, France. 176 pp. [in French]
Hong Youchong. 2002. Amber Insects of China. Beijing. Beijing Scientific Publishing House. 653 pp. 48 pls. [in Chinese]
Weitschat, W. & W. Wichard. 2002. Atlas of Plants and Animals in Baltic Amber. Munich. Dr. Friedrich Pfeil. 256 pp. [excellent resource! highly recommended!]
Selden, P. & J. Nudds. 2004. Baltic amber. pp. 131-141 in Evolution of Fossil Ecosystems. Chicago. University of Chicago Press.