A newly discovered plant and a wasp, as well as a developing fly larva, were found trapped in amber as evidence of a moment in prehistoric ecology.
If the image of an insect trapped in amber sounds familiar, you have George Poinar, Jr., the entomologist who made the discovery, to thank. His early work extracting insect DNA from Dominican amber directly inspired the premise of the movie “Jurassic Park.”
His latest study documents the first fossilized record of the plant genus Plukenetia and the first record of the plant genus from the Caribbean island of Hispaniola. “Fossilized flowers of this family are quite rare,” Poinar said. “We could only find one previously known fossil, from sedimentary deposits in Tennessee,” indicates Science Alert.
The famous Dominican amber is a fossilized form of resin from the extinct tree Hymenaea proterawhich scientists believe once grew in a humid rainforest ecosystem, based on the variety of life forms in the buried resin.
Species hidden in amber
This particular specimen was extracted from La Cordillera Septentrional mountain range. There is debate over the age of Dominican amber fossils, with conflicting theories based on the microorganisms used to date the specimens. Some say the presence of foraminifera (single-celled protists sometimes called “armored amoebae”) indicates that the amber formed about 20-15 million years ago.
Others suggest a period of 45-30 million years ago, based on the presence of coccoliths (calcium carbonate plates formed by single-celled phytoplankton called coccolithophores).
Poinar notes that this is further complicated because the amber was overturned and redeposited in turbulent sediment that later solidified into rock. Additionally, similar amber specimens discovered in Puerto Rico and Jamaica are dated to the Oligocene (33.9–23 million years ago) and Maastrichtian–Paleocene (72.1–66 million years ago), respectively.
The specimen is estimated to be around 30 million years old
The fossil reveals not only a new plant species, but an entire ecological microcosm, which Poinar believes could include pollination, predation and even parasitism. Modern specimens of the genus Euphorbia (living relatives of the fossilized plant) are indeed pollinated by small wasps, so this wasp may have played a similar ecological role.
fossilized wasp, Dominican Hambletonia, discovered and named by Poinar in 2020, is an encyrtid wasp, a group of parasites known to lay their offspring with the eggs or larvae of smaller insects, which become food for young developing wasps. Using high-resolution images, Poinar observed a tiny larva of Cecidomyiidae in one of the developing seeds of the flower and damage to the capsule in which the insect was located.
The wasp could have been attracted to the infected flower to lay its eggs
Of course, the wasp’s cunning plot was interrupted when a piece of sticky resin suddenly froze all three organisms in the painting they had been trapped in for millions of years. Poinar was so impressed by the beauty of this fossilized moment that he compared its appearance to 20th-century artistic movements, with the flower’s “elegant curves” and “long lines” reminding him of Art Nouveau styles, and the “dance” wasps, decorative shapes and “sharp angles” somehow resembled the Art Deco style.
“Based on interests, background and current environment, everyone has their own way of interpreting visual images in the natural world,” Poinar said. “An organism can be described, given a scientific name, and then stored in a taxonomic hierarchy.” Studies of fossils often focus on individual organisms and their place in the chronology of the tree of life, perhaps because it is rare to encounter complete specimens, let alone such a clear indication of multispecies interaction.
“In many cases, unrelated organisms end up buried together in amber, just by chance,” Poinar said. “But I feel that in this case the wasp was attracted to the flower, either for nectar or in attempts to lay an egg on the capsule containing the fly larva.”