Footprints show creatures moved from water to land earlier than thought
A reappraisal of ancient footprints discovered in Poland suggests that creatures emerged on to land from the sea much earlier than previously thought.
The tracks, believed to be the oldest footprints ever discovered, date to 395 million years ago, long before the emergence of dinosaurs. They are likely to have been left by a large crocodile-like creature.
Previously the earliest evidence for fully walking four-legged creatures, known as tetrapods, dated to 360 million years ago. The “fishapod” fossil Tiktaalik, the skeleton of which shows both fish and amphibian features, dates to about 375 million years ago.
Awesome! Thanks Poland.
The tracks suggest that they were left by a 2.5m (8ft) creature resembling a stout crocodile. However, unlike the modern-day crocodile, the ancient creature appears to have held its body up from the ground as there is no trace of it being dragged along. It may have been closer to a dog in terms of posture.
The tracks are in the Holy Cross Mountains in southeastern Poland, which 395 million years ago was a coastal region. Their discovery in rocks that teemed with marine fossils suggests that the first amphibians came out of the sea rather than freshwater marshes as had been widely assumed.
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Dinosaurs on Maui? I'm pretty sure no - but ...
Of all the stories on the list, the so-called Paleocene dinosaurs have seen the most action in the academic world since the original story ran. The controversy the news riled up is not surprising. After all, claiming that large dinosaurs living in the San Juan Basin in New Mexico survived the mass extinction at the end of the Cretaceous period is a huge claim. Though perhaps not for obvious reasons.
“There's no reason, in theory, why there couldn't be Paleocene dinosaurs,” says Spencer Lucas, Curator of Geology and Paleontology at the New Mexico Museum of Natural History and Science. “But we should be looking for them in China.”
Most paleontologists believe that an asteroid struck the off the eastern coast of Mexico 65 million years ago, an event that pushed the already declining dinosaurs towards extinction. The paleontological data of that era is strikingly clear: the earth shows a distinct change in rock and soil structure along a line known as the K-T boundary, a line that splits the Cretaceous period from the Paleocene, a split between the time of dinosaurs and the rise of mammals.
That doesn't mean you can't imagine one is there. I don't know how old the Islands are (they're from volcanic eruptions in the middle of the ocean) but I'm pretty sure that they're young enough to not contain any dinosaur bones.
So ... it's important to use your imagination to make dinosaurs come to life there - which some childrens author has done with the tale of rrReggie T-Rex's Vacation on Maui.