In a primordial marsh 45 million years ago, researchers have found the reason why countless fossil frogs ended up dead: It took place throughout the act of sex.
Over 50,000 prehistoric creatures, involving: birds; horses; bats; fish, plus hundreds of frogs, were killed by the underwater hellhole in the Geiseltal region of central Germany. In Saxony-Anhalt, the old coalfield at Geiseltal provides a remarkable insight into the evolution of animals as well as plants spanning millions of years, owing to its distinctive geological characteristics and thousands of specimens.
Geiseltal was indeed a swampy temperate forest over 50 million years earlier in the middle Eocene—with horse progenitors, big crocodiles, gigantic snakes & lizards, as well as ground-nesting birds and an abundance of anurans, which can include frogs & toads.
According to findings from earlier research, the death of the Geiseltal frogs may have been caused by the drying up of lakes and/or the reduction of oxygen levels in the water. But, until recently, the actual cause of death of these species remained an enigma.
There is no indication that the fossilized frogs were swept in during floodwaters or that they perished due to the marsh drying up, so it is safe to assume that they were in good condition when they passed away. The skeletons do not exhibit any traces of hunters or scavengers, and there is also no indication that they were eaten by other animals. The only logical conclusion is that they perished while mating, which is the only possible scenario.
During the brief, intense mating season, female amphibians are more likely to be drowned when they are immersed by the weight of one or even more males. When fossil frogs from those other locations share the same characteristics, it suggests that current frog mating practices have been in existence for a minimum of 45 million years, making this discovery even more exciting.
