info:eu-repo/semantics/article
An overview of hymenopteran cocoons as a tool to interpret ichnospecies of Fictovichnus (Pallichnidae) and other fossil cocoons of wasps
Fecha
2019-11Registro en:
Sarzetti, Laura Cristina; Genise, Jorge Fernando; Dinghi, Pablo Adrián; Molina, María Alejandra; An overview of hymenopteran cocoons as a tool to interpret ichnospecies of Fictovichnus (Pallichnidae) and other fossil cocoons of wasps; Society for Sedimentary Geology; Palaios; 34; 11; 11-2019; 562-574
0883-1351
CONICET Digital
CONICET
Autor
Sarzetti, Laura Cristina
Genise, Jorge Fernando
Dinghi, Pablo Adrián
Molina, María Alejandra
Resumen
Hymenopteran cocoons are complex structures constructed from silk by larvae and exhibit a wide range of morphologies, compositions, and textures. The recognition of the most relevant characters of modern cocoons is important for the accurate identification of trace fossils attributed to wasps, which are included in the ichnogenus Fictovichnus. Characters assessed in this study are length, equatorial diameter, diameters near the extremes, shape, color, texture, surface morphology, and occurrence (isolated or clustered). We mapped these characters onto a hymenopteran phylogeny, revealing that the distribution of most of them has no evident phylogenetic signal. In many cases, there is more than one character state in a single family, whereas others appear distributed among several groups. Ellipsoidal and ovoid cocoons, showing membranous texture are the most basal and common characters. Bilobated, subconical and fusiform shapes, clustering, nipple and pores seem to be autapomorphies for certain groups. Crabronidae, Pompilidae, Scolioidea and Thynnoidea construct hard coriaceous cocoons, which may show distinctive surface morphologies and would have the highest preservation potential in paleosols. Data presented herein show that both Fictovichnus sciuttoi and Fictovichnus aragon were correctly attributed to Crabronidae or Pompilidae, although Scolioidea and Thynnoidea cannot be ruled out because of the shape and coriaceous texture of their cocoons. According to the low phylogenetic signal of Hymenoptera cocoons found herein, it would be impossible to refine the affinities of these ichnospecies to particular taxa. The simple morphology of Fictovichnus gobiensis precludes a definitive attribution, either to wasps or to coleopterans, even after the new data presented herein.