[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Fossil Hunters Told to" Dig Deeper"
Peter Dodson & Steve Wang's latest dino fossil count as interpreted by the
Fossil hunters told: Dig deeper
"Lots" more dinosaurs await discovery, experts say.
By Tom Avril
Inquirer Staff Writer
Dinosaur hunters of the world, grab your picks and hammers!
You've barely scratched the surface, according to a study published
yesterday by scientists at the University of Pennsylvania and Swarthmore
A sophisticated statistical analysis suggests paleontologists have unearthed
fewer than one-third of the various kinds of dinosaurs to be found, the team
wrote in the online edition of Proceedings of the National Academy of
"Good news for paleontology," said Steve Wang, an assistant professor of
statistics at Swarthmore, who wrote the paper with Penn paleontologist Peter
Dodson. "There's still lots out there to find."
A handful of such predictions have been made in the past. But since Dodson
last did so in 1990, the rate of dinosaur finds has soared - the result of
exploration in new areas and by new people. Once largely the province of
white males from the United States, Britain and Canada, the field now
encompasses many paleontologists from fossil hotbeds such as China and
"It's no longer an imperialistic exercise," Dodson said.
And with the revelation that dinosaurs are ancestors of today's birds,
paleontologists have vigorously pursued the smaller creatures that evoke
their modern avian cousins.
"The emphasis has shifted from large dinosaurs that are going to add to the
'wow' factor of dinosaurs when mounted in museums," said Luis Chiappe,
paleontologist at the Natural History Museum of Los Angeles County.
From the early 1800s until 1990, science had identified 285 dinosaur genera.
(That's the plural of genus - a broader unit of classification than species,
as in the "homo" in Homo sapiens.)
Then, in just the last quarter-century, the number climbed to 527, a jump of
85 percent. The total number of "recoverable" genera is 1,844, Dodson and
Wang estimated. That doesn't count the likely hundreds of varieties that
were not preserved in rock.
Michael Foote, a professor in the department of geophysical sciences at the
University of Chicago, said the authors took a sound approach to the
"I really like this paper," said Foote, who was not involved with the work.
"I think this is, mathematically, a very rigorous attempt to deal with it."
Wang and Dodson used a statistical technique called an abundance-based
coverage estimator - an analysis that took into account how many fossil
finds throughout history represented new genera.
Loosely speaking, Wang said, that translates as follows:
"If you're always finding new things, you probably haven't found them all...
. If you keep finding the same things over and over and over, that gives you
an indication that you've probably found most things out there."
His calculations showed the reality to be somewhere in between.
He and Dodson projected that nearly 400 new varieties would be found in the
next 30 years. The pace will likely level off during the 22d century, they
The authors also tackled a question related to dinosaur extinction. Fossils
found to date suggest that dinosaur diversity was already in gradual decline
10 million years before the creatures' ultimate extinction, some experts
But Dodson and Wang's statistical method suggests that the population was
stable, and that we simply haven't found their fossils yet.
That finding is consistent with the prevailing view that the creatures
became extinct during a short period of time, as the result of a meteor
impact at the end of the Cretaceous period.
Chiappe, who was not involved with the research, warned that such analysis
must be viewed with some caution. If anything, he said, the new estimates
might be too low.
Some parts of the world are relatively untapped when it comes to dinosaur
fossils, notably Africa because of the turmoil in some countries, Chiappe
said. But even traditional hunting grounds still have much to yield, he
Chiappe himself was part of a team that reported a new small dinosaur
earlier this year, a 30-inch meat-eater from Germany dubbed Juravenator
And if the new predictions hold true, there's plenty more to come.
"It's a safe bet," Dodson said, "that a child born today could expect a very
fruitful career in dinosaur paleontology."
Contact staff writer Tom Avril at 215-854-2430 or firstname.lastname@example.org
email@example.com or firstname.lastname@example.org
"Keep away from people who try to belittle your ambitions. Small people
always do that, but really great ones make you feel that you too, can become
great." - Mark Twain