'Toilet-seat head' amphibian boosts catalogue of Triassic curiosities
The Triassic, which lasted from 252 to 200 million years ago, is not a geological period that looms large in the public consciousness. It lacks the Hollywood glamour of the Jurassic, and sadly none of its cast is as iconic as stars of the Cretaceous such as Tyrannosaurus rex. Yet, among palaeontologists the Triassic is renowned, and with good reason. It is both the age when weird wonders stalked the planet, and the beginning of the birth of the modern world. Alongside the earliest turtles, lizards, frogs, mammals and crocodiles roamed bizarre, implausible creatures, looking like sketches from the imagination of a fevered surrealist. Creatures like Longisquama, which looked like a lizard but had ludicrously long feather-like structures sprouting out of its back, or Dinocephalosaurus, a predatory marine reptile with a neck that was preposterously more than twice the length of its body. Collecting fossils in Triassic rocks is always exciting, because you never know what outlandish discoveries tomorrow will bring.
Last week, together with colleagues from Edinburgh, Paris and Lisbon, I was fortunate to add a new species to this panoply of Triassic curiosities. Metoposaurus algarvensis was a human-sized, two-metre long amphibian, with a flattened skull the size and shape of a toilet seat, but a toilet seat lined with hundreds of ferociously sharp teeth. One of my colleagues, with a greater gift of the gab than I, dubbed it the ‘super salamander’; some of the newspapers plumped for the ‘killer newt’. In truth, while these nicknames make for great soundbites, neither is particularly close. Metoposaurus belonged to a great prehistoric radiation of giant, predatory amphibians only distantly related to modern frogs, newts and salamanders, and some of which reached six metres or more in length. These fierce hunters would have made a swim in a Triassic lake or river an experience best avoided.
We collected the fossil material of Metoposaurus algarvensis in a beautiful area of the Algarve, southern Portugal, a region better known for its holidaymakers than its fossils. Prior to 2009, when our project began, only a few fragments of bone had ever been discovered. Our research team has discovered and begun to excavate a layer of rock that is incredibly rich in fossil bones, nearly all belonging to dozens of individuals of Metoposaurus, including wonderfully preserved and complete skulls. These Metoposaurus may have perished together as an ancient lake dried out in the hot and arid Triassic world.
Our new fossil discoveries are revealing for the first time the kinds of animals that lived in Portugal in the Late Triassic, 220 million years ago. Alongside Metoposaurus, crocodile-like reptiles called phytosaurs also terrorised the lakes. Although we have yet to find their fossils in the Algarve, discoveries in other parts of the world indicate that the earliest dinosaurs, as well as our own mammalian ancestors, also lived at this time. The Algarve amphibians and reptiles are very similar to those from distant rock sequences in Germany, the USA, and India, suggesting that environmental conditions allowed these groups to range widely across the supercontinent Pangaea, before being exterminated by a climate change-driven mass extinction at the end of the Triassic, 200 million years ago.
Fieldwork such as ours in the Algarve is the most fundamental work that palaeontologists do. Without it, we would have no conception of the grand narrative of the history of Life over the last 3.5 billion years. New fossil discoveries are arriving these days at an unparalleled rate and are of huge interest to the public and the media, as the storm over the ‘super salamander’ demonstrates. But more importantly, they are pieces in an enormous jigsaw puzzle that, just like the Higgs boson particle or the rediscovery of the bones of Richard III, help us to understand our own deep history, and our place in the cosmos. Illuminating and understanding ancient worlds makes us better placed to understand the beauty, and the fragility, of our own.
Dr Richard Butler
Birmingham Fellow & Academic Keeper, Lapworth Museum of Geology,
University of Birmingham