Many dino species 'undiscovered'

[Garrison Hilliard <garrison@efn.org>]

Many dino species 'undiscovered' 

Up to 500 dinosaur groups may remain undiscovered, yet our knowledge of the
creatures and how they were related is relatively complete, a scientist says. 
The figure of 500 may seem a lot, but this is a maximum possible value. 

The expert behind the study actually thinks the dinosaur fossil record is
between one-half and two-thirds complete, which is comparatively good. 

The data comes from an analysis of more than 250 dinosaur groups and their
family tree branches. 

Julia Heathcote, a graduate student at Washington University in St Louis, US,
used statistical analysis to determine how much missing data there might be on
dinosaur groups to how much researchers actually have. 

She also calculated how well proposed splits in the dinosaur family tree matched
the fossil evidence over time. 

Good record 

The research was carried out in collaboration with researchers from the Natural
History Museum in London. 

"The whole Dinosauria fossil record I would say is moderately good, which was a
surprise, becuase I thought it would be much worse," said Ms Heathcote. 

Although there had been previous attempts to analyse evolutionary patterns with
the dinosaur fossil record, she added, these patterns could only be interpreted
in a useful way when the ages of fossils were taken into account. 

Ms Heathcote claimed that her work could be added to by other researchers as new
dinosaur specimens are discovered and see where the new discovery fits in with
previous ones. 

Another calculation gave how much missing data there is to the minimum missing
data possible if all dinosaur groups were arranged in a family tree in order of
age. 

"[The analysis] draws together all of the data of the past 150 years," said Ms
Heathcote. "You can see how far back these dinosaurs go, see their relationships
with each other." 

Previous studies have attempted to provide complete dinosaur family trees.
Researchers at the University of Bristol have combined 150 previously published
evolutionary trees to form one supertree of 277 dinosaur groups. 


Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3475915.stm

Published: 2004/02/10 13:37:44 GMT