Department of Biological and Evolutionary Biology, Harvard University
December 15, 2023
Scientists at Harvard University’s Department of Biological and Evolutionary Biology have made an incredible discovery in the 312-million-year-old fossil of an insect. This discovery has pushed back the presumed origins of leaf mining behavior by 70 million years and provided new insights into the evolution of early insects. Their study shows that this behavior is linked to the evolution of early insects. The study was published on October 5, 2023, in New Phytologist.
The delicacy of prehistoric insects’ soft bodies makes them difficult to preserve as fossils. Due to this fragility, the bodies of these insects are often fragmented or incomplete, making scientific study difficult. As a result, paleontologists often rely on trace fossils to learn about these ancient insects, but they are almost exclusively found as traces of fossil plants. According to Dr. Richard J. Knecht, a candidate in the Department of Biological and Evolutionary Biology at Harvard University, the excellent preservation of fossil plants provides valuable insights into insect evolution and behavior.
In their study, researchers discovered endoparasitic trace fossils from the leaves of 312-million-year-old Carboniferous seed ferns. These trace fossils show the earliest signs of internal feeding within leaves, known as leaf mining. This discovery pushes the age of leaf mining behavior about 70 million years earlier than once believed.
The study also sheds light on the process and importance of internal nutrition in early insects. Feeding on plants internally is common in holometamorphic insects such as Lepidoptera (moths), Coleoptera (beetles), Diptera (flies), and Hymenoptera (wasps and sawflies), as the larvae make holes in the leaves and feed on the internal tissue, leaving a distinct trail. This behavior, identified in the Rhode Island Formation of the Carboniferous Period, shows how the exceptional preservation of this site allows for valuable insights into the behavior of ancient insects.
The study, led by Knecht and his team, highlights the significance of this discovery in furthering our understanding of early insect evolution and behavior and provides new insights into the origins of leaf mining by linking it to the evolution of early insects.
Source: scitechdaily.com
