Dinosaurs even the score
This is an amended version of the original blog
We know from the fossil record that dinosaurs and mammals must have co-existed for millions of years, and yet we know almost nothing about the nature of that relationship.
One clue, which appears to give mammals the upper hand, comes from the fossilised remains of a relatively large mammal, repenomamus robustus, discovered in 2005. It was found with the bones of a baby dinosaur in its stomach, and as the Smithsonian's Brian Switek speculates, it had apparently snacked on a young psittacosaurus shortly before it died.
Score it one-nil to the mammals. But as the old adage goes, one swallow doesn't make a summer, and most palaeontologists suspect the true nature of the relationship - given their size and dominance - is that predatory dinosaurs regularly preyed on mammals.
New evidence supporting this, more conventional predator-prey relationship, is emerging from the 80 million year old rocks of the Wahweap Formation in Utah's Grand Staircase National Monument. Reporting in the journal Geology a team lead by Professor Edward Simpson from Kutztown University has discovered evidence that predatory dinosaurs may have dug down into the soil to reach small burrowing mammals.
The first trace evidence shows scraping marks in the sandstone rocks made by a digging dinosaur, probably a deinonychus or Troodon. Below the claw marks numerous downward arching curves reveal the branching burrows of its intended victim - underground structures very similar to those made by small social mammals living today.
Based on the close association of these structures the researchers suggest a predatory dinosaur was trying to get at a mammal hiding in its burrow.
Commenting on the findings Brian Switek says "If you look carefully....it appears that the dinosaur was repeatedly sticking its foot into the hole and raking out sediment".
Behaviour that certainly appears consistent with a carnivore digging out its next meal. Life it seems - at least for early mammals in the Mesozoic - was nasty, brutish and short.
Tom Feilden adds...
Firstly can I say I'm very grateful for the comments posted on my original blog. I made an honest mistake, and appreciate the opportunity to explain what happened.
Correct attribution is an essential component of good journalism, especially in the field of science writing, where such a premium is put on the ownership of ideas and on accuracy and fact checking.
In writing my original blog I mistakenly assumed that Brian's article, posted on the Smithsonian website, had in fact been written by professor Edward L. Simpson, whose name (along with the other authors involved in the original research published in Geology) appears prominently at the bottom of the article. Hence my attribution of the ideas and quotes in the blog solely to professor Simpson.
Indeed if you try printing out Brian's blog (as I did) you will find that his strap-line falls off the bottom of the page entirely. I shouldn't have missed it, but I'm afraid I simply didn't spot Brian's name, and assumed the blog was a synopsis of the academic paper by the named authors, which I could therefore draw from.
As a result, in describing the research I subsequently used both the original paper and the blog as if they were a single source, reproducing the arguments and, inadvertently, attributing a direct quotation from Brian's blog to professor Edward L. Simpson. It was certainly never my intention to claim the ideas as my own.
Clearly I didn't look closely enough at the sourcing for the Smithsonian blog. It was an honest mistake, one we've acknowledged to the Smithsonian, but obviously it shouldn't have happened. It's been a salutary lesson for me, and I can only offer my sincere apologies.