Big news in the world of tiny frogs: German zoologists have named five new species from the island of Madagascar.
Three of them – smaller than a thumbnail – are so closely related that they belong to a new genus, the taxonomic rank that sits above species.
In a self-confessed attention-seeking move by the scientists, the name of the new genus is Mini.
It gets cornier
The new species are named Mini mum and Mini scule (8–11 mm long) and the larger Min iature (15 mm).
Madagascar, the fifth-largest island in the world, “a little larger than mainland France,” as the researchers describe it, has more than 350 frog species.
They have evolved with varying pressures from a range of habitats: the island’s climate is tropical along the coast, temperate inland, and arid in the south. In a day you can travel between lush rain forests, tropical dry forests, plateaus and deserts.
Some of them half the size of bees
The five new species belong to a group of frogs commonly referred to as narrow-mouthed frogs, a highly diverse family found on every continent except Antarctica and Europe.
Although most narrow-mouthed frogs are small to moderately large, many are tiny.
The group boasts the smallest frog in the world – Paedophryne amauensis from Papua New Guinea, mature specimens of which reach a length of only 7.7 mm – about half the size of a honey bee.
The researchers, in a prepared statement, note that what’s remarkable here is that, in the smallest frogs, “miniaturisation” has evolved independently – often several times within a single region, as highlighted in this new study.
This means they all have a limited range, a factor that makes them vulnerable to catastrophe in the event of a disaster such as fire or a prolonged extreme heatwave caused by climate change.
Welcome to the world, try to hang on
Mini mum in particular has an extremely limited range and a small known population.
Freshly revealed to the world, the researchers, in their paper published in the journal PLoS ONE, to recommend it be classified as critically endangered, a heartbeat from winking out as a species.
The other two new species, Rhombophryne proportionalis and Anodonthyla eximia, are also just 11–12 mm long – bee-sized – and are much smaller than their closest relatives.
“When frogs evolve small body size, they start to look remarkably similar, so it is easy to underestimate how diverse they really are,” says Mark Scherz, a PhD candidate at Ludwig Maximilian University in Munich, and lead author of the new study.
“Our new genus name, Mini, says it all. Adults of the two smallest species Mini mum and Mini scule are eight to 11 millimetres long, and even the largest member of the genus, Miniature, at 15 millimetres, could sit on your thumbnail with room to spare.”
Dr Frank Glaw, Head of the Herpetology Section at the Bavarian State Collection of Zoology in Munich, and Mr Scherz’s co-author, said that finding tiny frogs in the leaf litter is hard work.
“Calling males often sit one or two leaves deep and stop calling at the slightest disturbance,” he said. “It can take a lot of patience to find the frog you are looking for.”