Exploiting Nondietary Resources in Deep Time: Patterns of Oviposition on Mid-Mesozoic Plants from Northeastern China

Premise of research. Even though the fossil record of oviposition provides a rich archive of plant resource use, it is deficient for a fundamental reason. Very few analyzable oviposition data have been collected, particularly from the preangiospermous Mesozoic. Methodology. From northeastern China, we investigated 1817 plant specimens of the Early Cretaceous Jehol Biota (125 Ma), of which 60 specimens exhibited ovipositional damage; 3886 specimens of the Middle Jurassic Yanliao Biota (165 Ma) revealed 296 specimens with ovipositional damage; and 408 specimens from the Late Triassic Beipiao Biota (205 Ma) yielded 19 specimens with ovipositional damage. First, we analyzed herbivore ovipositor structure of 68 Jehol and Yanliao insect species, resulting in nine ovipositor morphotypes. Second, we analyzed oviposition lesions of plant specimens from all three biotas, yielding 15 oviposition damage types (DTs). Third, we linked ovipositor morphotype to oviposition DTs. Pivotal results. The most heavily oviposited Jehol plant group was conifers, particularly Liaoningocladus boii; Equisetites (horsetails) were subordinately attacked. For the Yanliao Biota, the most intensely oviposited plant group was bennettitaleans, particularly Anomozamites, responsible for 46.6% of all ovipositor associations in the total Jehol-Yanliao-Beipiao data set. The conifer Yanliaoa and the ginkgophyte Ginkgoites had subordinate levels of oviposition. The Beipiao Biota revealed a more balanced distribution of oviposition, with cycads and ferns having the greatest ovipositional damage. Conclusions. These three time slices, separated by two 40-million-year intervals, indicate major shifts in oviposition preferences. An examination is warranted into the factors promoting the pronounced oviposition levels on Yanliao Anomozamites, a bennettitalean.