Preprint: Please note that this article has not completed peer review.

Fossil amber reveals springtails’ longstanding dispersal by social insects

Ninon Robin, Cyrille D'Haese, Phillip Barden

Abstract

Background: Dispersal is essential for terrestrial organisms living in disjunct habitats and constitutes a significant challenge for the evolution of wingless taxa. Springtails (Collembola), the sister-group of all insects (with dipluran), are reported since the Lower Devonian and thought to have originally been subterranean. The order Symphypleona is reported since the early Cretaceous with genera distributed on every continent, implying an ability to disperse over oceans although never reported in marine water contrary to other springtail orders. Despite being highly widespread, modern springtails are generally rarely reported in any kind of biotic association. Interestingly, the fossil record has provided occasional occurrences of Symphypleona attached by the antennae onto the bodies of larger arthropods. Results: Here, we document the case of a ~16 Ma old fossil association: a winged termite and ant displaying not some, but 25 springtails attached or closely connected to the body. The collembola exhibit rare features for fossils, reflecting their courtship and phoretic behaviors. By observing the modes of attachment of springtails on different arthropods, the sex representation and ratios in springtail antennal anatomies in new and previously reported cases, we infer a likely mechanism for dispersal in Symphypleona. By revealing hidden evidence of modern springtail associations with other invertebrates such as ants and termites, new compelling assemblages of fossil springtails and the drastic increase of eusocial insects’ abundance over Cenozoic (ants/termites comprising more than the third of insects in Miocene amber), we stress that attachment with winged casts of ants and termites may have been a mechanism for the worldwide dispersal of this significant springtail lineage. Moreover, by comparing the general constraints applying to the other wingless soil-dwelling arthropods known to disperse through phoresy, we suggest biases in the collection and observation of phoretic Symphypleona related to their reflexive detachment and infer that this behavior continues today. Conclusions: The specific case of tree resin entrapment represents the (so far) only condition uncovering the actual dispersal mechanism of springtails - one of the oldest terrestrial arthropod lineages living today. Associations with soil-dwelling social insects over time would have been at the origin of this behavioural specialization.

Keywords
Springtails – dispersal – phoresy – Symphypleona – social insects – Dominican amber

Figures

Background

Results

Discussion

Conclusion

Methods

Declarations

References

Supplementary Files

STATUS: In Review

Comments: 0
PDF Downloads: 3
HTML Views: 11

Integrity Check:

Peer Review Timeline

Version 1

Posted 23 Jul, 2019

  • No community comments so far
  • Review #2 received

    Received 04 Aug, 2019

  • Editorial decision: Minor revision

    On 04 Aug, 2019

  • Reviewer #2 agreed

    On 29 Jul, 2019

  • Review #1 received

    Received 29 Jul, 2019

  • Reviewer #1 agreed

    On 26 Jul, 2019

  • 5 reviewer(s) invited

    Invitations sent on 25 Jul, 2019

  • Submission checks complete

    On 19 Jul, 2019

  • Editor assigned

    On 30 Jun, 2019

  • Editor invited

    On 29 Jun, 2019

  • First submitted

    On 26 Jun, 2019

More from BMC Evolutionary Biology

Comments (0)

Comments can take the form of short reviews, notes or questions to the author. Comments will be posted immediately, but removed and moderated if flagged.

Learn more about our company.

Preprint: Please note that this article has not completed peer review.

Fossil amber reveals springtails’ longstanding dispersal by social insects

Ninon Robin, Cyrille D'Haese, Phillip Barden

STATUS: In Review

Comments: 0
PDF Downloads: 3
HTML Views: 11

Integrity Check:

  • Article

  • Peer Review Timeline

  • Related Articles

  • Comments

Abstract

Background: Dispersal is essential for terrestrial organisms living in disjunct habitats and constitutes a significant challenge for the evolution of wingless taxa. Springtails (Collembola), the sister-group of all insects (with dipluran), are reported since the Lower Devonian and thought to have originally been subterranean. The order Symphypleona is reported since the early Cretaceous with genera distributed on every continent, implying an ability to disperse over oceans although never reported in marine water contrary to other springtail orders. Despite being highly widespread, modern springtails are generally rarely reported in any kind of biotic association. Interestingly, the fossil record has provided occasional occurrences of Symphypleona attached by the antennae onto the bodies of larger arthropods. Results: Here, we document the case of a ~16 Ma old fossil association: a winged termite and ant displaying not some, but 25 springtails attached or closely connected to the body. The collembola exhibit rare features for fossils, reflecting their courtship and phoretic behaviors. By observing the modes of attachment of springtails on different arthropods, the sex representation and ratios in springtail antennal anatomies in new and previously reported cases, we infer a likely mechanism for dispersal in Symphypleona. By revealing hidden evidence of modern springtail associations with other invertebrates such as ants and termites, new compelling assemblages of fossil springtails and the drastic increase of eusocial insects’ abundance over Cenozoic (ants/termites comprising more than the third of insects in Miocene amber), we stress that attachment with winged casts of ants and termites may have been a mechanism for the worldwide dispersal of this significant springtail lineage. Moreover, by comparing the general constraints applying to the other wingless soil-dwelling arthropods known to disperse through phoresy, we suggest biases in the collection and observation of phoretic Symphypleona related to their reflexive detachment and infer that this behavior continues today. Conclusions: The specific case of tree resin entrapment represents the (so far) only condition uncovering the actual dispersal mechanism of springtails - one of the oldest terrestrial arthropod lineages living today. Associations with soil-dwelling social insects over time would have been at the origin of this behavioural specialization.

Figures

Background

Results

Discussion

Conclusion

Methods

Declarations

References

Learn more about our company.