Family for Darwin’s strangest animal
Bird-like dinos hatched eggs
PARIS, June 28, (AFP): Charles Darwin, Mr Evolution himself, didn’t know what to make of the fossils he saw in Patagonia so he sent them to his friend, the renowned paleontologist Richard Owen. Owen was stumped too. Little wonder. “The bones looked different from anything he knew,” said Michael Hofreiter, senior author of a study published Tuesday in Nature Communications that finally situates in the tree of life what Darwin called the “strangest animal ever discovered”.
“Imagine a camel without a hump, with feet like a slender rhino, and a head shaped like a saiga antelope,” Hofreiter, a professor at the University of Potsdam, told AFP.
Macrauchenia patachonica — literally, “long-necked llama” — also had a long rubbery snout and with its nostrils high on the skull just above its eyes.
For nearly two centuries, biologists and taxonomists argued over the pedigree of this bizarre beast, which weighed 400 to 500 kilos (850 to 1100 pounds), lived in open landscapes, and snacked on grass and leaves.
But its mixed bag of body features, and a paucity of DNA evidence, made it nearly impossible to determine whether M. patachonica was truly related the llama after which it was named. As it turns out, not really. A new kind of genetic analysis revealed that Macrauchenia was more akin to an ancient placental order known as Perissodactyla that includes horses, rhinos and tapirs.
Difficult
“We had a difficult problem to solve here,” said lead author of the new study Michael Westbury, also at the University of Potsdam.
“When ancient DNA is so degraded and full of unwanted environmental DNA, we rely on being able to use the genomes of close relatives as a kind of scaffold to reconstruct fossil sequences,” he said in a statement.
But Macrauchenia — itself an evolutionary dead end — didn’t have any close cousins that we know of.
To solve the puzzle, Westbury and a 20-strong team of scientists used mitochondrial DNA extracted from a fossil found in southern Chile to decode the extinct mammal’s origins.
Inherited from the mother alone, the mitochondrial genome is smaller and has more copies in the cell — and thus in fossils — than DNA from the more complex nuclear genome, Hofreiter explained.
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PARIS: Feathered dinosaurs that walked on two legs and had parrot-like beaks shared another characteristic with modern birds — they brooded clutches of eggs at a temperature similar to chickens, a study showed Wednesday.
Ostrich-sized oviraptors, ancestors to birds, sat on their eggs to incubate them at 35 to 40 degrees Celsius (95 to 104 degrees Fahrenheit) — a range comparable with modern hens (37.5 C), researchers reported in the journal Palaeontology.
A team from China and France measured oxygen atoms from the shells and embryo bones of seven oviraptor eggs from the Upper Cretaceous period some 100 to 66 million years ago.
The analysis revealed the temperature at which the embryo was forming during its incubation, explained study co-author Romain Amiot, a paleontologist at France’s CNRS research institute.
Amiot and a team used the eggs of oviraptors because they are known to have been egg brooders.