It’s taken a long time, however scientists could have lastly discovered Earth’s first fowl.
It began in 1993 on Vega Island, a frigid, windswept rock off the Antarctic Peninsula. A largely headless skeleton of a loon-size diving hen emerged from rocks that, at 68 million years previous, predated the dinosaur extinction. The species, which scientists named Vegavis iaai, offered a puzzle: What hen was it a feather of?
Practically 20 years later, a 2011 Antarctic expedition turned up a hen cranium that extra not too long ago was matched with Vegavis iaai. In an evaluation printed Wednesday within the journal Nature, researchers are sticking their necks out to counsel that the mysterious Antarctic avian is an historic relative of at the moment’s geese and geese, and the oldest identified fashionable hen.
“It’s precisely the form of factor we have to assist fill in an evolutionary hole,” stated Christopher Torres, a paleontologist at Ohio College and an creator on the paper. However he conceded, “that’s additionally what makes it so extremely controversial.”
Prior to now few a long time, Dr. Torres stated, researchers taking a look at hen genomics prompt that some fashionable hen households — significantly waterfowl and recreation fowl — in all probability appeared earlier than the asteroid influence that worn out the non-avian dinosaurs. However earlier than the invention of Vegavis within the Nineties, no attribute fossils had been recognized, leaving a spot between molecular knowledge and rocky bodily proof.
The combination of archaic and fashionable skeletal traits within the unique Vegavis specimen additionally made it tough to position, stated Chase Brownstein, a paleontologist at Yale College who was not concerned within the analysis. Some researchers prompt that Vegavis might need been certainly one of a number of households of extinct Mesozoic birds — some with toothed payments and clawed wing-fingers — that didn’t survive the Cretaceous interval extinction. Others believed it was a contemporary hen, nearer to loons, grebes or geese.
The cranium present in 2011 helped breach this prehistoric logjam.
The researchers of the brand new paper generated a near-complete three-dimensional reconstruction of the hen’s head. They discovered that Vegavis had the toothless beak and mind form attribute of contemporary birds, Dr. Torres stated, in addition to particular cranium traits that they argue counsel the hen is carefully associated to fashionable waterfowl. However — and right here’s the foolish half — the cranium is kind of completely different from these of residing geese or geese. Its beak was lengthy and pointed. It had massive glands to take away salt from the physique, and highly effective jaw muscular tissues that allowed the hen to snap its jaws shortly underwater.
All the skeleton factors towards a hen that dove underwater after fish and propelled itself with highly effective kicking legs, Dr. Torres stated. That’s not like any fashionable water fowl, “and way more just like what we see in fashionable loons and grebes.”
Regardless of the hen’s loony physique plan and head, the superb particulars of its cranium — together with its jaw and beak — present particular traits that counsel waterfowl, Dr. Torres stated.
Whereas Dr. Brownstein known as the invention of the Vegavis cranium “thrilling,” he isn’t satisfied that it’s sufficient to settle the controversy over the animal’s id — or to make clear when hen lineages like waterfowl appeared. However even probably the most conservative interpretation of the cranium signifies that fashionable birds and their closest toothless family members had been extraordinarily anatomically numerous on the finish of the Cretaceous interval, he stated.
Others are extra enthusiastic.
The truth that a hen with such fashionable options was round by the tip of the dinosaurs’ reign means that different main lineages of residing birds had been doubtless current as nicely, stated Gerardo Álvarez Herrera, a paleontologist with the Bernardino Rivadavia Pure Sciences Argentine Museum who was not concerned within the research. It’s attainable that additional exploration will uncover “the ancestors of ostriches, fowls, neoaves and geese that will have roamed alongside non-avian dinosaurs.”