Navigation Links
Fresh analysis of dinosaur skulls by penn researchers finds 3 species are 1
Date:8/9/2013

A new analysis of dinosaur fossils by University of Pennsylvania researchers has revealed that a number of specimens of the genus Psittacosaurus once believed to represent three different species are all members of a single species. The differences among the fossil remains that led other scientists to label them as separate species in fact arose from how the animals were buried and compressed, the study found.

"Because of the vagaries of fossilization, no two fossils are the same," said senior author Peter Dodson, professor of anatomy in Penn's School of Veterinary Medicine and professor of paleontology in the School of Arts and Sciences' Department of Earth and Environmental Science. "Animals are alive and they die, but what's crucial in paleontology is what happens to the animals after they die."

The research involved a cutting-edge technique, known as three-dimensional geometric morphometrics, which uses lasers to generate data about the shape of different specimens. This is the first time the approach has been used to study dinosaur fossils and could lead to a re-examination of the taxonomic classifications of additional dinosaur species as well as other long-extinct fossil organisms.

Brandon Hedrick, a doctoral student in the Department of Earth and Environmental Science, led the study in collaboration with Dodson. Their research will be reported in the journal PLOS ONE.

The investigation focused on dinosaurs in the genus Psittacosaurus, a word that comes from the Greek for "parrot lizard." The group was named for the animal's beaked face, not unlike that of a turtle. Originally discovered in 1923, 15 species have been classified as Psittacosaurus, though a recent analysis confirmed only nine of these as definite members of the genus. These animals were small plant-eaters that lived 120 to 125 million years ago. Paleontologists have discovered Psittacosaurus fossils in Mongolia, China and Russia and possibly in Thailand.

"Meat-eaters are sexy; plant-eaters are not," Dodson said. "This isn't a flashy dinosaur. But it has an interesting feature in that it's one of the most abundant dinosaurs known to science."

Indeed, many hundreds of Psittacosaurus specimens have been found. This abundance made the genus ideal for Hedrick and Dodson's comparative study, as it is easier to determine relationships within and between species when there are more individuals to compare.

"For example, if you have a single dachshund and a single beagle, they may appear to be different species until you found 40 dachshund-beagle mixes of various grades to examine," Hedrick said.

The scientists examined Psittacosaurus skulls discovered in the fossilized ashes of the Lujiatun beds of northeastern China's Yixian Formation. Paleontologists had previously identified the skulls as belonging to three different species, Psittacosaurus lujiatunensis, P. major or Hongshanosaurus houi.

To compare and contrast the specimens, the researchers used two techniques. First they conducted a traditional study in which they examined every skull that had been classified as one of those three species a total of 74 specimens for a variety of characteristics that had been used in prior studies to distinguish the species. The Penn team also compared these fossils to skulls that had been classified as belonging to eight other Psittacosaurus species.

Next they completed a more high-tech analysis of 30 skulls from the three named species. Using a hand-held stylus that captures a point in space relative to a transmitter, they pinpointed 56 "landmarks," or particular anatomical locations, on each fossil and compared the relative position of those marks between specimens. They also used a hand-held, laser-emitting scanner to make a three-dimensional image of each specimen, similar to a CT scan, from which they also collected landmark data.

Based on the "old-fashioned" method of examining the physical skulls, the researchers concluded that the three purported species were in fact one. They propose that all three can be considered members of the species P. lujiatunensis.

Results from the geometric morphometric analysis, though not sufficient on its own to classify species, supported this conclusion and suggested that how an animal's body was crushed as it fossilized from the top, from the side or twisted could lead to inaccurate species determinations.

"Our study found all of these false 'species' that are not biological species but are apparent species caused by the process of fossilization," Dodson said.

The Penn team said their investigation shows the value of traditional taxonomic analysis, while also revealing the potential of a new approach to analyzing fossils.

"Hopefully this will open up the paleontological community to using three-dimensional geometrics morphometrics in a variety of ways," Hedrick said. "This technique has limitless applications to understanding dinosaurs."


'/>"/>

Contact: Katherine Unger Baillie
kbaillie@upenn.edu
215-898-9194
University of Pennsylvania
Source:Eurekalert

Related biology news :

1. Diverse bacteria on fresh fruits, vegetables vary with produce type, farming practices
2. Pesticide application as potential source of noroviruses in fresh food supply chains
3. Invention opens the way to packaging that monitors food freshness
4. Thailand: Astonishing 10 new species of semi-aquatic freshwater earthworms revealed
5. Antibacterial agent used in common soaps found in increasing amounts in freshwater lakes
6. Earliest sea cow ancestors originated in Africa, lived in fresh water
7. First freshwater mosasaur discovered
8. Greater effort needed to move local, fresh foods beyond privileged consumers
9. Assessing a new technique for ensuring fresh produce remains Salmonella-free
10. NC State leads national effort to evaluate fresh water sustainability in the southern US
11. New equipment is breath of fresh air for childrens lung researchers
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/26/2016)... BANGALORE, India and LONDON ... Infosys Finacle, part of EdgeVerve Systems, a ... ), and Onegini today announced a partnership to ... banking solutions.      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ... banks to provide their customers enhanced security to ...
(Date:4/15/2016)... -- A new partnership announced today will help life ... a fraction of the time it takes today, ... insurance policies to consumers without requiring inconvenient and ... rapid testing (A1C, Cotinine and HIV) and higi,s ... pulse, BMI, and activity data) available at local ...
(Date:4/13/2016)... -- IMPOWER physicians supporting Medicaid patients in Central ... in telehealth thanks to a new partnership with higi. ... patients can routinely track key health measurements, such as ... when they opt in, share them with IMPOWER clinicians ... retail location at no cost. By leveraging this data, ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... Diego, CA (PRWEB) , ... April 29, 2016 , ... ... Foundation (NSCF) to support the development of a patient-specific stem cell therapy for the ... in the lab of Dr. Jeanne Loring at The Scripps Research Institute in San ...
(Date:4/28/2016)... ... April 28, 2016 , ... Connecticut Innovations ... growing companies, today announced the launch of VentureClash , a $5 million ... , “VentureClash looks to attract the best early-stage companies here in Connecticut, ...
(Date:4/27/2016)... ... ... Shimadzu Scientific Instruments (SSI) will be showcasing a broad ... Expo. Shimadzu’s high-performance instruments enable laboratories to test cannabis products for potency, moisture, ... booth 1021 to learn how Shimadzu’s instruments can help improve QA/QC testing, peak ...
(Date:4/27/2016)... ... April 27, 2016 , ... The ... announce the appointment of John Tilton as Chief Commercial Officer.  Mr. Tilton joined ... of the founding commercial leaders responsible for the commercialization of multiple orphan drug ...
Breaking Biology Technology: