Stories tagged fossil

Apr
13
2007

Two years ago, everyone was talking about the work of paleontologist Mary Schweitzer: she noticed that thin slices of a 68-million-year-old fossil femur from a Tyrannosaurus rex looked like they still contained soft tissue. (See photos of the bone.) Using antibodies to the collagen protein, she showed that the bone still contained intact collagen molecules—the main component of cartilage, ligaments, and tendons.

Hello, dinos?: A new study shows that preserved collagen from a 68-million-year-old Tyrannosaurus rex is similar to that of chickens. (Photo courtesy Danelle Sheree)
Hello, dinos?: A new study shows that preserved collagen from a 68-million-year-old Tyrannosaurus rex is similar to that of chickens. (Photo courtesy Danelle Sheree)

She used antibodies to a type of collagen extracted from chickens. The fact that the antibodies stuck suggested that T. rex collagen is similar to that of birds. And when she compared the preserved soft tissue to that of modern animals, the closest match was an emu—a flightless bird.

To learn more about the collagen in the T. rex bones, Schweitzer worked with John Asara, a chemist at Harvard University, to analyze it using mass spectrometry.

The Economist describes the technique this way:

This technique identifies molecules (or fragments of molecules) from a combination of their weight and their electric charges. Knowing the weights of different sorts of atoms (and of groups of atoms that show up regularly in larger molecules, such as the 20 different amino acids from which proteins are assembled) it is usually possible to piece together fragments to form the profile of an entire protein.

When Asara compared the profile he'd created to proteins from living animals, the closest matches were to chickens and ostriches. (Schweitzer and Asara's study was published in the April 13, 2007, issue of the journal Science.)

Many paleontologists already believed, based on fossil bones, that birds are dinosaurs or their descendants. But this new paper provides even more evidence of the fact.

Buzz stories on the subject from last year:

Recent news articles:

It's the day before Thanksgiving, and I'm too lazy to look for real science news, so here's a cute story about how rock star Brian Eno identified a diosaur fossil that a fan was wearing as a necklace.

Fossil find

by Gene on Nov. 10th, 2006

A father-and-son team have discovered the first complete skull of a plesiosaur ever found in Montana.

A teenager in Argentina recently found the largest fossil bird ever discovered. The extinct, flightless bird, which has not yet been named, stood 10 feet tall and may have weighed as much as 400 pounds! Its skull sports a hooked beak, and is large enough to have eaten animals as large as dogs or sheep. Fortunately, it went extinct three to four million years ago.

Sep
30
2006

Baby girl Lucy: Image from Wikipedia
Baby girl Lucy: Image from Wikipedia

Lucy-like fossil is older and more complete

The fossil including an entire skull, torso, shoulder blade and various limbs was discovered at Dikaka, some 400 kms northeast of the capital Addis Ababa near the Awash river in the Rift Valley.

"The finding is the most complete hominid skeleton ever found in the world," Zeresenay Alemseged, head of the Paleoanthropological Research Team, told a news conference. Reuters

The fossil has been named "Selam", which means peace in Ethiopia's official Amharic language.

Zeresenay said she belonged to the Australopithecus afarensis species, which includes Lucy, and is thought to be an ancestor to modern humans.

"The Dikika girl stands as one of the major discoveries in the history of palaeoanthropology," research team leader Zeresenay Alemseged said, citing the remarkably well-preserved condition of the bones, the geological age and completeness of the specimen.Cosmos Magazine

The following is the abstract of the original article describing the baby, which was authored by Zeresenay Alemseged, Fred Spoor, William H. Kimbel, René Bobe, Denis Geraads, Denné Reed and Jonathan G. Wynn, and appeared in Nature on September 20, 2006.

"Understanding changes in ontogenetic development is central to the study of human evolution. With the exception of Neanderthals, the growth patterns of fossil hominins have not been studied comprehensively because the fossil record currently lacks specimens that document both cranial and postcranial development at young ontogenetic stages. Here we describe a well-preserved 3.3-million-year-old juvenile partial skeleton of Australopithecus afarensis discovered in the Dikika research area of Ethiopia. The skull of the approximately three-year-old presumed female shows that most features diagnostic of the species are evident even at this early stage of development. The find includes many previously unknown skeletal elements from the Pliocene hominin record, including a hyoid bone that has a typical African ape morphology. The foot and other evidence from the lower limb provide clear evidence for bipedal locomotion, but the gorilla-like scapula and long and curved manual phalanges raise new questions about the importance of arboreal behaviour in the A. afarensis locomotor repertoire."

Additional reading: BBC News