Mating and aggregative behaviors among basal hexapods in the Early Cretaceous

PLoS One. 2018 Feb 21;13(2):e0191669. doi: 10.1371/journal.pone.0191669. eCollection 2018.

Abstract

Among the many challenges in paleobiology is the inference and reconstruction of behaviors that rarely, if ever, leave a physical trace on the environment that is suitable for fossilization. Of particular significance are those behaviors tied to mating and courtship, individual interactions critical for species integrity and continuance, as well as those for dispersal, permitting the taxon to expand its distribution as well as access new habitats in the face of local or long-term environmental change. In this context, two recently discovered fossils from the Early Cretaceous amber of Spain (ca. 105 mya) give a detailed view of otherwise fleeting ethologies in Collembola. These occurrences are phylogenetically spaced across the class, and from species representing the two major clades of springtails-Symphypleona and Entomobryomorpha. Specifically, we report unique evidence from a symphypleonan male (Pseudosminthurides stoechus Sánchez-García & Engel, 2016) with modified antennae that may have functioned as a clasping organ for securing females during mating on water's surface, and from an aggregation of entomobryomorphan individuals (Proisotoma communis Sánchez-García & Engel, 2016) purportedly representing a swarming episode on the forest floor. We demonstrate that the mating behavioral repertoire in P. stoechus, which is associated with considerable morphological adaptations, likely implied elaborate courtship and maneuvering for guarantee sperm transfer in an epineustic species. These discoveries reveal significant behaviors consistent with modern counterparts and a generalized stasis for some ancient hexapod ethologies associated with complex mating and courtship and social or pre-social aggregations, so critical to specific constancy and dispersal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Ecosystem
  • Female
  • Fossils*
  • Insecta / physiology*
  • Male
  • Sexual Behavior, Animal*

Grants and funding

Financial support was provided by the Spanish Ministry of Economy and Competitiveness project CGL2014-52163. This is also a contribution to the Division of Entomology, University of Kansas Natural History Museum.