Does Anyone Really Know How Many Kinds of Birds There Are? – #365papers – 2017 – 151

#365papers for May 31, 2017

Barrowclough, Cracraft, Klicka, and Zink, 2016, How many kinds of birds are there and why does it matter?: PlosONE, v. 11, e0166307.

What’s it about?

When discussing species diversity, especially in terms of conservation efforts, it’s important to have a good definition of ‘species.’ Here, the authors show that depending on how you define a species, there may be twice as many kinds of birds as we usually think. Continue reading

How Aluminum in Zircon Can Tell Us What Happened Billions of Years Ago – #365papers – 2017 – 150

#365papers for May 30, 2017

Trail, Tailby, Wang, Harrison, and Boehnke, 2017, Aluminum in zircon as evidence for peraluminous and metaluminous melts from the Hadean to present: Geochemistry, Geophysics, Geosystems, v. 18, p. 1580-1593.

What’s it about?

Zircon is a mineral that forms in igneous rocks. As the rocks erode away, the zircons often survive and can be mixed into younger rocks, including new igneous rocks. Here, the authors use the concentration of aluminum in the zircons to determine the type of igneous rock the zircon originally formed in. Continue reading

The Magnetic Field and Aurorae of Jupiter – #365papers – 2017 – 149

#365papers for May 28, 2017

Connerney and 21 others, 2017, Jupiter’s magnetosphere and aurorae observed by the Juno spacecraft during its first polar orbits: Science, v.356, p. 826-832.

What’s it about?

With the instrumentation on the Juno spacecraft, scientists can now measure the strength and shape of the magnetic field around Jupiter and explore the planet’s aurorae (like our Aurora Borealis). Continue reading

Peeking Under Jupiter’s Clouds – #365papers – 2017 – 148

#365papers for May 28, 2017

Bolton and 42 others, 2017, Jupiter’s interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft: Science, v. 356, p. 821-825.

What’s it about?

We finally have a spacecraft close enough to Jupiter that we can take photos of the planet’s poles and better understand what is happening below the cloud tops.

Jupiter’s south pole. Credits: NASA/JPL-Caltech/SwRI/MSSS/John Landino

Continue reading

Calcium Can Tell Us About Ancient Ecosystem Structure – #365papers – 2017 – 147

#365papers for May 27, 2017

Martin, Vincent, Tacail, Khaldoune, Jourani, Bardet, Balter, 2017, Calcium isotopic evidence for vulnerable marine ecosystem structure prior to the K/Pg extinction: Current Biology, v. 27

What’s it about?

The variations of the amounts of stable isotopes (that is non-radioactive) found in rocks and fossils can be used to help us understand patterns of weather, of vegetation, and of who’s eating whom in modern and fossil rocks, bones, teeth, and shells. Most of the time carbon, oxygen, and nitrogen are used for this.

The authors here show that calcium isotopes can be used to understand tropic level (where organisms are on the food chain) in modern and fossil animals. Their work shows that large marine reptiles likely went extinct at the end of the Permian Period because they all lived at the same trophic level. There was some sort of ecological change that eradicated their food supply and the marine reptiles could not recover. Continue reading

Extinction in the Permian – #365papers – 2017 – 146

#365papers for May 26, 2017

Lucas, 2017, Permian tetrapod extinction events: Earth-Science Reviews, v. 170, p. 31-60.

What’s it about?

The Permian ended with the largest marine extinction ever to strike the Earth, with 95% of species going extinct. This paper discusses life on land, specifically tetrapods (amphibians and reptiles at that time) and how they went extinct. Continue reading

Ann Hinga. Phone Call for Ann Hinga – #365papers – 2017 – 145

#365papers for May 25, 2017

Stidham, Patnaik, Krishan, ingh, Ghosh, Singla, and Kotla, 2017, The first darter (Aves: Anhingidae) fossils from India (late Pliocene): PlosONE, v12, e0177129

What’s it about?

There’s a family of birds called the Anhingidae, which includes anhingas and darters. This is a description of a new fossil darter from India. Continue reading

Getting Mountains to Move – #365papers – 2017 – 144

#365papers for May 24, 2017

Malone, Craddock, Schmitz, Kenderes, Kraushaar, Murphey, Nielsen, and Mitchell, 2017, Volcanic initiation of the Eocene Hart Mountain Slide, Wyoming, USA: Journal of Geology, v 125

What’s it about?

The Hart Mountain slide is famous (in geology) for being a land slide that covers at least 3500 km3 and may have moved as far as 85 km. How do you get something that big started? This paper shows that the emplacement of an igneous body below what became the slide may have helped trigger the movement. Continue reading

When Did We Stop Being Apes? – #365papers – 2017 – 143

#365papers for May 23, 2017

Fuss, Spassov, Begun, and Bohme, 2017, Potential hominin affinities of Graecopithecus from the Late Miocene of Europe: PlosONE, v. 12, e01771127

What’s it about?

Yesterday’s paper was about the age of the new species Graecopithecus, an early relative of humans. This paper discusses what separates Graecopithecus from other apes and what unites it more closely with humans.

Why does it matter?

With a clear definition of what distinguishes humans and their closest relatives from apes, and by also having an age for the oldest member of the human lineage, we can better understand how we came to be who we are.

Why did I read this?

This paper was all over social media. I felt obligated to read it.

Maybe the oldest hominin? – #365papers – 2017 – 142

#365papers for May 22, 2017

Bohme, Spassov, Ebner, Geraads, Hristova, Kirscher, Kotter, Linnemann, Prieto, Roussiakis, Theodorou, Uhlig, and Winklhofer,  2017, Messinian age and savannah environment of the possible hominin Graecopithecus from Europe: PlosONE, v. 12, e0177347.

What’s it about?

Hominins are humans and their non-ape ancestors. Graecopithecus appears to fall into this group. Using geochemical methods plus study of the sediments that the fossils came from, the researchers show that this fossil is the earliest hominin by a few hundred thousand years and that the environment was one of wooded grasslands or braided streams and supports the ‘Savannah Hypothesis’ of human evolution. Continue reading