Sexual Intercourse Involving Giant Sperm in Cretaceous Ostracode
R. Matzke-Karasz,1,*
R. J. Smith,2
R. Symonova,3
C. G. Miller,4
P. Tafforeau5
Reproduction with giant sperm occurs in distinct groups scattered
over the animal kingdom. Although experiments in
Drosophila assessed the influence of different selection pressures on this
character, no information was available on its long-term stability.
Sub-micrometer-resolution synchrotron quantitative phase tomography
(holotomography) of exceptionally well-preserved three-dimensional
Cretaceous ostracode fossils from the Brazilian Santana Formation
indicates that ostracode reproduction with giant sperm persisted
for at least over the past 100 million years. Remnants of the
male sperm pumps as well as giant, inflated female sperm receptacles
evidence that, despite high costs, reproduction with giant sperm
can be an evolutionary successful strategy.
2 Lake Biwa Museum, Kusatsu, Shiga 525-0001, Japan.
3 Department of Zoology, Charles University, 12844 Prague, Czech Republic.
4 Department of Palaeontology, Natural History Museum, London SW7 5BD, UK.
5 European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France.
* To whom correspondence should be addressed. E-mail: r.matzke{at}lrz.uni-muenchen.de
