Friday Headlines, February 28, 2020
THE LATEST IN THE GEOSCIENCES
This week in paleontology (AKA Fossil Friday)
- A new Eocene bird from Utah
This week in geology
- The Earth formed faster than we thought
This week in the environment
- When rising waters cooled the Earth
Evidence for Wide Dispersal in a Stem Galliform Clade from a New Small-sized Middle Eocene Pangalliform (Aves: Paraortygidae) from the Uinta Basin of Utah (USA)
In plain English, a fossil of a small-sized member of a group of birds called pangalliforms was found in Utah. Pangalliforms are the birds ancestral to the modern galliform birds (which includes chickens, quails, grouse, ptarmigans, and turkeys). Finding pangilliform bird in the Eocene of Utah tells us that these birds were widespread around the Earth at that time, rather than limited to a small geographic area.
The naming of the new species was based upon a single bone called the coracoid, which is part of the shoulder in birds. Shoulders are unique between bird species, because of different wing shapes and functions, thus making this single coracoid bone sufficient for naming a new species.
The Earth formed much faster than previously thought
When considering the origins of life on Earth and the potential for life elsewhere in the universe, the rate at which new planets form matters. By measuring isotopes of iron (that is the relative amount of iron atoms of different weight), researchers found that the formation of our planet happened much faster than we had originally thought – only about 5 million years. (It’s fast, astronomically and geologically speaking.)
Rapid formation of planets means that it’s likely that there are many more planets out in the universe that we thought and that there may be more Earth-like planets (with water and other ingredients for life) out there.
Sea level fingerprinting of the Bering Strait flooding history detects the source of the Younger Dryas climate event
Usually, we associate rising sea level with global warming. Warming leads to melting of ice caps which leads to more water in the oceans.
Cooling during the last glaciation lowered sea level so much that a land bridge connecting Asia and North America emerged from the ocean. This was the Bering Land Bridge, by which it is hypothesized that humans migrated into North America.
After the glaciation ended (about 18,000 years ago) the Earth warmed again. Temperatures rose. But there was a moment (geologically speaking) about 12,000 years ago when things got cold again. This is called the Younger Dryas event.
The authors of this paper show that when the Bering Land Bridge was submerged due to rising waters, the mixing of northern and southern waters caused the Younger Dryas cooling. So we have an unexpected case where rising oceans were related to global cooling.
EPOCH isotopes 