Horned frog staring at the camera.

One of the four new species described, Megophrys oreocrypta, which was found in Meghalaya state © Systematics Lab, DU

Four new species of frog from one of the wettest regions on Earth

The amphibians belong to a group known as horned frogs, named for their pointy upper eyebrows. Typically quite robust amphibians, the new species described inhabit the remote forests that cover the Himalayan foothills extending down into northeast India.

Found right across south eastern Asia, there has long been confusion among scientists about the taxonomy - or classification - of Asian horned frogs.  

Dr Stephen Mahony, the Museum scientist who has described these new species, says, 'This group is considered to be part of Archaeobatrachia, which are the ancient frogs.'

Only around 4% of all frogs belong to this group. 'Horned frogs are thought to be primitive amphibians from a lineage that is between 50 and 80 million years old,' explains Stephen. 

For over 150 years researchers thought that Jerdon's white-lipped horned frog, Megophrys major, represented a single species living across vast swaths of south eastern Asia.

A brown-grey frog sitting on leaves.

It turns out that Jerdon's white-lipped frog is just one of many similar looking species spread across northeastern India  © R.G. Kamei

But after spending 11 years piecing together reports and papers, tracking down original collections in museums and even going out into the field to where these specimens were first collected, Stephen has found that things were by no means that simple.

These monumental efforts, in collaboration with colleagues at the Museum, University College Dublin and the University of Delhi, have now been published as a monograph in Zootaxa

'It is mostly down to the fact that there was a lot of confusion as to which specimens were the type specimens,' explains Stephen. This refers to the individual frog on which the entire species was named.

'Without knowing what specimen is the type, it is difficult to known which species a certain name applies to,' Stephen continues. 'Scientists were then further adding to the confusion by describing new species based on these misconceived ideas and so the problem just got bigger and bigger.'

The wettest place on Earth

In order to resolve these issues, Stephen had to go back to the source of the confusion that swirled around the amphibians by delving into museum collections.

From here he traced all the literature both published and unpublished, in the form of hand written notes, jar labels and museum catalogues, relating to all the original specimens purporting to belong to this species.    

Lush forest carpeting the hills of northeastern India

The Khasi Hill in Meghalaya state are home to some of the wettest places on Earth © Daniel J. Rao/Shutterstock

The detective work even took Stephen's Indian colleagues and coauthors Dr Rachunliu G. Kamei and SD Biju to northeastern India including Meghalaya state, one of the wettest regions on Earth.

The town of Sohra (historically known as Cherrapunjee), Meghalaya, receives on average 11,777 millimetres of rain every single year and holds the record for the most rain that has ever fallen in a single year when it received 26,470 millimetres of rain between 1860 and 1861.

To put this into perspective, damp London receives just 583 millimetres of rain per year.

Dr Rachunliu G. Kamei, says, 'We only ever see horned frogs at night time in the forest and they are generally very difficult to find because they occur in low numbers.

'So often over several nights of searching we only encounter a few individuals. Working in the forest at night time in remote jungles of northeast India can be dangerous due to problems of insurgency and the likelihood of encountering wild animals.

'But the hardship is worthwhile when we find exciting species.'

It turned out that M. major is not a single species in itself, but made up of five separate ones. Each looks very similar, but have their own restricted range and show distinct genetic differences.

horned-frog-india-two-column

One of the new species, the giant Himalayan horned frog, is the largest species of horned frog now found in the region © Systematics Lab, DU

From this, Stephen was able to describe the Himalayan horned frog (Megophrys himalaya), Garo white-lipped horned frog (Megophrys oreocrypta), the yellow spotted white-lipped horned frog (Megophrys flavipunctata) and the giant Himalayan horned frog (Megophrys periosa). At up to 11.2 centimetres long, M. periosa is now the largest species of horned frog found in northeast India.  

That such a wide ranging frog was found to be at least five separate species in such a relatively small region means that right across south eastern Asia it is more than likely that each population of horned frog is actually its own distinct species. 

New species in Vietnam

In fact, these are not the only Megophrys frogs that Stephen has been involved with describing this year, as another two new species of frogs from the mountains of Vietnam have been recently been published in Zootaxa.

Found on Indochina's highest mountain at an altitude of 3,143 metres, they have been named the Mount Fansipan horned frog (Megophrys fansipanensis) and the Hoang Lien horned frog (Megophrys hoanglienensis) after the locations in which they were first discovered.

A little red coloured horned frog

Both new species from Vietnam, including Megophrys fansipanensis, are thought to be endangered © Benjamin Tapley/ZSL

The frogs live along clear mountain streams that weave their way through lush ravines and bamboo forests. 

The mountains that jut out of the lowlands and blanketed in forest are unfortunately a popular destination for tourists who flock to the hills to enjoy the cooler air and picturesque surroundings. With all these tourists come a lot of rubbish and faeces, which the researchers have found littering the forests and streams.

It means that having only just been described by science, these frogs may now be lost. Both species, found only within their restricted montane range, are thought to be endangered. 

Read more

  • Read Dr Stephen Mahony's full monograph describing how he figured out muddle in Zootaxa.
  • Find out more about the two new species from Vietnam by reading the full paper also in Zootaxa