Caught in the act: the first record of copulating fossil vertebrates.
The behaviour of fossil organisms can typically be inferred only indirectly, but rare fossil finds can provide surprising insights. Here, we report from the Eocene Messel Pit Fossil Site between Darmstadt and Frankfurt, Germany numerous pairs of the fossil carettochelyid turtle Allaeochelys crassesculpta that represent for the first time among fossil vertebrates couples that perished during copulation. Females of this taxon can be distinguished from males by their relatively shorter tails and development of plastral kinesis. The preservation of mating pairs has important taphonomic implications for the Messel Pit Fossil Site, as it is unlikely that the turtles would mate in poisonous surface waters. Instead, the turtles initiated copulation in habitable surface waters, but perished when their skin absorbed poisons while sinking into toxic layers. The mating pairs from Messel are therefore more consistent with a stratified, volcanic maar lake with inhabitable surface waters and a deadly abyss.
Department of Geosciences, University of Tübingen, 72076 Tübingen, Germany. walter.joyce@uni-tuebingen.de
Walter G
WG
Joyce
Norbert
N
Micklich
Stephan F K
SF
Schaal
Torsten M
TM
Scheyer
D000818:Animals; D003307:Copulation; D005260:Female; D005580:Fossils; D005858:Germany; D008297:Male; D010163:Paleontology / Q000379:methods*; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal; D014426:Turtles / Q000502:physiology*; D014714:Vertebrates / Q000502:physiology*; D014873:Water Pollutants / Q000633:toxicity
D014873:Water Pollutants