Info about 65m-yr-old dinosaur teeth uncovered
Washington: In a new study, researchers from two disparate fields have discovered the teeth of 65-million-year-old dinosaurs.
With the help of University of Florida mechanical engineering professor W. Gregory Sawyer and UF postdoctoral researcher Brandon Krick, Florida State University paleobiologist Gregory Erickson determined the teeth of hadrosaurs — n herbivore from the late Cretaceous period — had six tissues in their teeth instead of two.
“When something has been in the ground 65 million years, by and large we pick it up and we look at it and say, ‘oh, look at what has been preserved.’ But we don’t mechanically interrogate fossils to see if there is other information,” Sawyer said.
“When we started to mechanically interrogate these teeth, what we found was all of these properties were preserved, and one other thing: these teeth were a lot more complicated than we thought,” he said.
For years, Erickson, who has a background in biomechanical engineering and studies bone biomechanics as a paleobiologist, had thought so. So he turned to the UF Tribology Laboratory, which researches the science of friction and surface wear.
Engineers don’t often see the interesting paleontological questions, Sawyer said. One look at the surface of the dinosaur teeth piqued his interest, however, because he is intrigued by how wear occurs across surfaces with different materials.
The shape of the tooth made him think it was much more complex than previously thought.
From an engineering perspective, Sawyer said his lab often works with composites that contain different material properties that wear differently, so the question was whether just two materials — enamel and dentine — would wear the way the hadrosaur teeth did. Sawyer and Krick thought not, and turned to nanoindenters and microtribometers.
Just a decade ago, a paleontologist might not have asked engineers for help, and they could not have helped him. In the last 10 years, however, Sawyer said advances in engineering — tribology and nanoscience, in particular — make it possible to test more materials, even those millions of years old.
Erickson said reptilian dinosaurs have been dismissed as simplistic creatures in their feeding and dental structure. They were herbivores, their teeth composed of enamel and dentine. The fossil record did little to contradict that.
Testing with nanoindenters and microtribometers, however, proved the conventional wisdom wrong.
“Hadrosaurs’ teeth were incredibly complicated, among the most complex of any animal,” Sawyer said.
“These dinosaurs had developed a lot of tricks,” he said.
The duck-billed hadrosaur was a toothy creature with up to 1,400 teeth, Erickson said. The teeth migrated across the chewing surface, with sharp, enamel-edged front teeth moving sideways to become grinding teeth as the teeth matured.
The adaptation allowed hadrosaurs to bite off chunks of bark and stems and chew them to a digestible mush, leading Erickson to describe them as “walking pulp mills.”
The teeth wore down at the rate of 1 millimeter per day, cycling through the jaw like a conveyor belt, before falling out or being swallowed. The dinosaurs lost about 1,800 teeth a year, leaving behind plenty of fossils for testing.
When the fossils emerged from batteries of tests, the researchers found six tissues in the tooth structure, not two.
“Modern tools told us there were different materials in there,” Sawyer added.
The study has been published in the journal Science.
More from India
More from World
More from Sports
More from Entertaiment
- Dr Subhash Chandra Show: Aspiring for more than what you have!
- ISIS to buy first nuclear weapon from Pak?
- Mumbai: CCTV captures assailant with gun at Film City
- Mathura SSP receives death threat letter, message for PM Modi
- BJP now central pole of Indian politics: Arun Jaitley
- Reservation issue: Police register case against Bainsla, 20 others
- Watch: Fast N Facts @ 7:30pm
- Zee Media exclusive chat with 'Welcome to Karachi' cast
- Zee Media exclusive interview with Haryana CM Manohar Lal Khattar
- Haridwar: Hotel Radisson Blu sealed for polluting Ganga
- Girl in Punjab's Pathankot quit studies for fear of eve-teasing
- Special: Furious over rising water crisis, people take to the streets
- UP Minister allegedly threatens, abuses Gonda businessman
- Manali: Heavy corruption found in environmental taxes
- Couple in Bihar asked to pay Rs 50,000 as 'tax' for inter-caste marriage
- IPL 2015 Final: MI vs CSK - As it happened...
- IPL 8 Final: We need to be at our best against Mumbai, says Michael Hussey
- Heatwave leaves 153 dead in Telangana, Andhra Pradesh
- Heatwave continues in North India; death toll in Andhra Pradesh, Telangana more than 400
- Heatwave kills 223 in AP, Telangana, Chandrababu Naidu announces compensation; Delhi records hottest day
- 'Tanu Weds Manu Returns' starts on a good note at the Box Office!
- CBSE.nic.in 12th XII Results 2015: CBSE Board (cbseresults.nic.in) Class 12th XII Exam Results 2015 to be announced on May 25
- CBSE 12th Result 2015 to be announced on Monday
- Death threat to PM Narendra Modi ahead of Mathura rally sends police into tizzy
- Standoff with LG: Arvind Kejriwal calls emergency session of Delhi Assembly
- Organisation demands re-examination of AIPMT 2015
- Kejriwal completes 100 days in office, AAP says centre 'shadow boxing' over row with LG
- CBSE Class 12th Board Results 2015 to be announced on Monday, May 25
- Top 5 shopping destinations in Delhi!
- IPL 2015: Not easy for fast bowler to win many MOM in one season, says Ashish Nehra