A potpourri of nifty discoveries to remind us, in the midst of so much political anguish, what an amazing universe we live in.
Using uranium-lead dating, a research team led by Lida Xing from the China University of Geosciences and Michael Caldwell from the University of Alberta dated the fossils to about 99 million years old. A technique called synchrotron x-ray micro–computed tomography allowed the researchers to get a close look at the tiny specimens inside the amber without having to break them apart.
Astronomers have been wrestling with a few puzzles about the neighborhood for a while now. First, there’s just not nearly as much stuff out there, all told, as they would expect. Also, it’s odd that Neptune is more massive than the closer-in Uranus. And many of the small objects in the outer swath — like Sedna, a strange dwarf planet — follow extreme, stretched orbits at stark angles to the rest of the solar system’s more orderly inhabitants.
Those quirks suggest that something must have stirred up the pot after the planets and large moons clumped together and formed out of the cloud of dust surrounding our sun early in its life. One possible culprit is a star that might have slipped next to our solar system and tugged objects off their original paths, throwing some out of the solar system entirely and skewing the orbits of others.
These armored dinos first appeared in Asia around 125 million years ago and had reached western North America by about 77 million years ago. One other known North American ankylosaurid, a different species found in New Mexico that’s 3 million years younger than the newfound dino, also has a rugged noggin comparable to A. johnsoni’s. The new find adds to evidence that at least two types of ankylosaurids migrated from Asia to North America during the late Cretaceous, possibly via a land bridge between the continents, the researchers report July 19 in PeerJ.
- July 19, 2018
- Harvard T.H. Chan School of Public Health
- Women who eat a high amount of fruits and vegetables each day may have a lower risk of breast cancer, especially of aggressive tumors, than those who eat fewer fruits and vegetables, according to a new study.