Last month, we brought you “Ancient Amphibian Death Ditch”. This month, it’s “Ancient Amphibian Sex Swamp Death Trap”. In a tragic tale of lust and loss, hundreds of frisky frogs are believed to have died in a prehistoric swamp, lured there by the promise of sexy times.

Remains of the ill-fated amphibians, who died around 45 million years ago, were found in an ancient swamp in what is now the Geiseltal area of central Germany. Studying the fossils, paleontologists from University College Cork have come to the conclusion the poor froggos may have given up the ghost during the throes of passion.

Their findings are published in the journal Papers in Palaeontology.

“As far as we can tell, the fossil frogs were healthy when they died, and the bones don’t show any signs of predators or scavengers – there’s also no evidence that they were washed in during floods, or died because the swamp dried up,” said study leader Daniel Falk in a statement.

“By process of elimination, the only explanation that makes sense is that they died during mating.”

These ancient frogs were predominantly land-dwellers, the authors found. Those that could be categorized largely belong to the Pelobatidae family, also known as Europen spadefoot toads, which currently has just one living genus. 

The Pelobatidae family are terrestrial and prefer to live in deserts and other arid habitats, predominantly in western Eurasia and northwestern Africa. They generally only take to the water to breed and lay eggs – a treacherous task for a lil frog accustomed to a drier life.

Especially for females, who “are at higher risk of drowning as they are often submerged by one or more males – this often happens in species that engage in mating congregations during the short explosive breeding season,” senior author Professor Maria McNamara explained. 

This could explain how so many of them came to meet their maker in such an untimely fashion, the authors conclude. A big price to pay for a bit of hanky panky.

The findings of the new study put to bed a long-standing mystery surrounding the Geiseltal frogs, as previous studies suggested they met their sticky end at the hands of oxygen depletion in the swamp’s water, or the drying up of lakes.

The watery death trap also claimed the lives of other ancient animals – over 50,000 of them, in fact – including fish, birds, bats, and horses. Around 45 million years ago, when the frogs are thought to have died, the Earth was much hotter. The area of Geiseltal would have been a swampy subtropical forest – and, clearly, a very dangerous place to be an ancient beast.

But it’s not just the ancient swamp of Geiseltal that posed a risk to frogs in search of some lovin’, McNamara added, and this could teach us a lot about frog evolution:

“What’s really interesting is that fossil frogs from other sites also show these features, suggesting that the mating behaviours of modern frogs are really quite ancient and have been in place for at least 45 million years.”