How much do we really know about dinosaurs?

Every week it seems a new dinosaur is being discovered. Each discovery represents progress in piecing together the Jurassic world, but how do scientists put their knowledge in context?

How do paleontologists know how much (or how little) of the true fossil record they're seeing? Are there thousands of dinosaur species we know nothing about? Hundreds?

Recently, researchers at the University of Bristol, in England, attempted to zoom out and capture a broader picture of paleontological progress.

One way to paint a more accurate picture of the fossil record (and its relative quality), is to better understand how new dinosaurs are discovered. Research shows that an average of one to two new species is found for every new fossil-rich rock formation. Some scientists have used this link to grade how much (or how little) scientists know about dino lineages.

Such efforts are flawed, researcher Mike Benton says. As his new study points out, that correlation leaves room for debate: do rocks drive dino discoveries, or do dinos drive rock discoveries?

In other words, are discoveries limited by the number of untapped geological resources? Or are discoveries limited by selective digging? It may be that as researchers all flock to where the action is, they're leaving whole swaths of the fossil record buried.

The new paper on the subject -- published in the journal Paleontology -- doesn't attempt to offer a definitive answer to these questions. Instead, Benton simply reminds researchers that they need to pay more attention the role biases play in shaping our understanding of the fossil record.

"I have been worried for a while that some of the popular correction methods actually make things worse," Benton said in a press release. "By removing the numerical signal of the formations, localities, or collections they were actually removing a huge amount of real information, and producing a resulting curve that is meaningless."

"The fossil record is clearly incomplete, and it is clearly biased by many factors, but many of the supposedly 'corrected' diversity curves we have seen recently may actually be further from the truth than the raw data," he concluded.

So, is the fossil record more like 1 or 50 percent of reality? Benton doesn't know. And his new paper suggests no else does either.