Posted on 15 February, 2008 by Ed Yong
Their heads and bodies of bats have amassed an extraordinary array of adaptations that have make them lords of the night sky. Today, the thousand-plus types of bats make up a fifth of living mammal species. Richard Dawkins once described the evolution of bats as “one of the most enthralling stories in all natural history” and as of this week, the story has a clearer beginning.
The success of bats hinges on two key abilities: their mastery of flight, a feat matched only by birds and insects; and echolocation, the ability to navigate their way through pitch-blackness by timing the reflections of high-pitched squeaks. For evolutionary scientists, the big question has always been: which came first?
The ‘clawed bat’
Until now, fossil bats haven’t provided any clues for all of them show signs of both echolocation and flight. But a stunning new fossil, discovered by Nancy Simmons from the American Museum of Natural History is an exception and it provides a categorical answer to the long-running debate – the earliest bats could fly but could not echolocate.
The new creature hails from the Green River in Wyoming and is known as Onychonycteris, meaning “clawed bat”. Its fossils date back to about 52.5 million years ago and by comparing it to other prehistoric bats, Simmons found that it is the most ancient member of this lineage so far discovered. It acts as a ‘missing link’ in bat evolution, much like the famous Archaeopteryx hinted that birds may have evolved from dinosaurs.
Filed under: Animal behaviour, Animal evolution, Animal kingdom, Bats, Evolution, Mammals, Palaeontology | Tagged: bat evolution, Bats, echolocation, flight, fossils, nature, Onychonycteris, science | 2 Comments »
Posted on 14 January, 2008 by Ed Yong
For some dinosaurs, the best strategy was to grow fast and breed early. New fossil evidence suggests that at least three species, including celebrities like Tyrannosaurus and Allosaurus, were having sex in their teens. In this way, their pace of growth and maturity was closer to that of modern birds and mammals than it would be to a reptile scaled-up to the same size.
They also started to breed well before they had finished growing, which suggests that they lived relatively short and brutal lives and needed as much time as possible to reproduce before they met an untimely demise. Modern back-boned animals with high adult death rates use a similar strategy.
Filed under: Animal kingdom, Dinosaurs, Palaeontology | Tagged: Allosaurus, dinosaur growth, Dinosaurs, fossils, life history, medullary bone, reproductive strategy, science, T.rex, Tenontosaurus, Tyrannosaurus | 2 Comments »
Posted on 15 December, 2007 by Ed Yong
Cowboys have been lassoing cattle for several centuries, but it turns out that fungi developed the same trick 100 million years ago when dinosaurs still walked the Earth.
Alexander Schmidt and colleagues from the Humboldt University of Berlin found evidence of this ancient Wild West scene in a beautiful chunk of French amber.
The amber piece lacked the transparent clear beauty of a jeweller’s piece and the debris and dirt inside it suggests that it came from tree sap that had fossilised after it had fallen to the ground. There, it perfectly preserved the species living in the leaf litter, including a species of predatory fungi and the small worms – nematodes – that Schmidt thinks it hunted.
The fungus’s weapons were single cells coiled into rings just 10 micrometres in diameter. A thousand of these tiny loops could fit in a centimetre, but they were more than large enough to accommodate a blundering nematode. Once a worm swam through, the fungi constricted its snare, trapping the animal.
Filed under: Fungi, Palaeontology | Tagged: amber, carnivorous fungi, fossils, nematode, predatory fungi, science | 7 Comments »
Posted on 30 November, 2007 by Ed Yong
One of our extinct evolutionary cousins, Paranthropus robustus, may have walked like a man but it socialised like a gorilla. Using only fossils, UCL scientists have found that P.robustus males were much larger than females, competed fiercely for mates and led risky lives under heavy threat from predators.
I wrote an article about the cool new finding for Nature Network. Here’s the opening and you can read the full article here.
A single fossil can tell you about the shape, diet and movements of an extinct animal but with enough specimens, you can reconstruct their social lives too.
Charles Lockwood of University College London used an unusually large collection of fossils to peer back in time at the social structures of one of our closest extinct relatives, Paranthropus robustus, which inhabited southern Africa between 1.2 million and 2 million years ago.
Filed under: Animal behaviour, Animal kingdom, Evolution, Human evolution, Mammals, Palaeontology, Primates, Sex | Tagged: dimorphism, fossils, gorillas, Paranthropus robustus | Comments Off