This Ancient Swamp Was a Sex Death Trap For Frogs 45 Million Years Ago

If you want to lure a bunch of prehistoric frog to a sticky end, the best way is the promise.

The remains of hundreds of ancient frog were found in a swamp in what is now Germany around 45 million years ago.

Since they were discovered in the fossil bed, the mystery of why the frog died has been a puzzle.

"As far as we can tell, the fossil frog were healthy when they died, and the bones don't show any signs of predator or scavengers - there's also no evidence that they were washed in during floods, or died because the swamp dried up," says Daniel Falk of

The only plausible explanation is that they died during sex.

One of the most amazing fossil sites in the world is where the frog were found.

It's located in a coalfield that used to be a fossil fuel. The preservation of ancient remains is amazing.

Small mammals, bats, birds, crocodiles, reptiles, and fish are some of the fossils that have been recovered from the area.

There are animals. There are a lot of frog. The layer in which the frog were found was 50 million years old and was a swamp.

You may be wondering, "So what?" There are lots of frog in the wet. There are a lot of other Frogs that don't, and most of the Frogs identified in the lignite seem to be in this category. Most of the frog were categorized as belonging to the Pelobatidae family.

There is only one group of these Frogs that live today. It lives on dry land and only comes back to the water during the breeding season. For females, who can suffocate under the attention of ardent admirers, this can be quite dangerous.

A frog's skeleton broke in half in the water.

According to Maria McNamara of University College Cork, females are at higher risk of being drowned as they are submerged by one or more males.

This may seem odd, but it is not a problem in the world of frog breeding.

One species of frog can extract eggs from a dead female by squeezing her and then fertilize the eggs. This isn't completely out of the realm of possibility, but it hasn't been seen in modern Pelobatidae.

The analysis can help us understand frog evolution through the ages.

"What's really interesting is that fossil frog from other sites also show these features, suggesting that the mating behaviors of modern frog are very old and have been in place for at least 45 million years," McNamara says.

Papers in Palaeontology contains the research.