First fossil record of stalked spermatophores with sperm (Collembola: Hexapoda)

Abstract

Spermatozoa and stalked spermatophores in Baltic amber represent the first report of these reproductive structures in the fossil record. A comparison of this material with sperm and simple stalked spermatophores from extant invertebrates indicates that the fossil structures originated from a springtail (Collembola: Hexapoda). This conclusion is supported by the presence of a female springtail, Sminthurus longicornis Kock and Berendt (Sminthuridae: Symphypleona), in the same piece of amber. This specimen, which appears to have been molting at the time of death, is adjacent to objects interpreted as springtail eggs. The present find establishes the existence of the indirect method of sperm transfer by the late Eocene (40 Ma).

Keywords:

• Fossil sperm
• Fossil spermatophore
• Collembola
• Springtail
• Baltic amber
• Sminthurus longicornis
• Eocene

Notes

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