Who Are the Heterostraci? – #UREES270 – 2018

Randle and Sansom, 2017, Phylogenetic relationships of the ‘higher heterostracans’ (Heterostraci: Pteraspidiformes and Cyathaspididae), extinct jawless fishes: Zoological Journal of the Linnean Society, v. 181, p. 910-926

What’s it about?

The Heterostraci are armored jawless fishes that are a sister group (evolutionary offshoot, if you will) to the lineage that later led to fishes with jaws. This paper is a discussion of how the various species of fish tucked into the Heterostraci are actually related. Continue reading

Anaspids, Jawless Fish Whose Armor Tell Us Where They Belong – #UREES270 – 2018

Keating and Donoghue, 2016, Histology and affinity of anaspids, and the early evolution of the vertebrate dermal skeleton: Proceedings of the Royal Society B, v. 283: 20152917

What’s it about?

The anaspids were a group of early, jawless fishes with bony armor covering their bodies. The authors discuss the structure of the bony armor and complete analyses to determine where anaspids actually fit into the evolutionary history of vertebrates. Continue reading

What Happens When a Cat Jumps on Your Keyboard While You’re Composing a Blog Post? – #UREES270 – #365papers- 2018

Leslie, 2014, Impacts of phylogenetic nomenclature on the efficacy of the U.S. Endangered Species Act: Conservation Biology, v. 29, p. 69-77

What’s it about?

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I read this paper last year!

 

Clean Desk I Spy

I spy…

I spy…

A placoderm, Triceratops, a single celled organism…
A pointer, life’s consciousness juice, and medicine for pain…
A vertebra and chopsticks, and a grid of LEDs…
Phone buttons, computer buttons, and a piece of the Cretaceous-Paleogene boundary…

What else do you see?

Defining and Distinguishing Species of Organisms – #365papers – 2018 – 40

de Queiroz, 2007, Species concepts and species delimitations: Systematic Biology, v. 56, 879-886.

What’s it about?

Species is a difficult concept in biology, even if it seems straightforward. The author of this paper shows that it really is as simple as it seems, but the means of distinguishing one species from another. The problem isn’t in the definition of species but in the distinction among species. Continue reading

Putting Together the Tetrapod Vertebra – #365papers – 2018 – 39

Pierce, Ahlberg, Hutchinson, Molnar, Sanchez, Tafforeau, and Clack, 2013, Vertebral architecture in the earliest stem tetrapods: Nature, v. 494, doi: 10:1038/nature11825

What’s it about?

In mammals, each vertebra is a single bone. However, these apparently singular bones are actually composed of several bones that are sutured together. This paper explores the individual bones that get fused together, and their origins in the transitional forms between fish and terrestrial tetrapods (four legged animals, e.g. amphibians, reptiles, birds, and mammals). Continue reading

Methods for Extracting Proteins from Fossils: Paleoproteomics – #365papers – 2018 – 38

Cleland and Schroeter, 2018, A comparison of common mass spectrometry approaches for paleoproteomics: Journal of Proteome Research, DOI: 10.1021/acs.jproteome.7b00703

What’s it about?

Recently, there has been great discussion about the extraction of proteins from fossils. This paper outlines various methods, and their strengths and weaknesses, for extracting proteins from ancient bones. Continue reading

Using Glass to Estimate Altitude – #365papers – 2018 – 37

Dettinger and Quade, 2015, Testing the analytical protocols and calibration of volcanic glass for the reconstruction of hydrogen isotopes in paleoprecipitation, in DeCelles, Ducea, Carrapa, and Kapp, eds., Geodynamics of a Cordilleran Orogenic System: The Central Andes of Argentina and Northern Chile: Geological Society of America Memoir 212, p. 261-276.

What’s it about?

Isotopes of oxygen and hydrogen from water can give us insights into the altitude at which that water fell to the ground as rain. Some of this water can become incorporated into volcanic glass (in ash), preserving the isotopic values of the original water. Continue reading

Did Bolide Bombardment Kill Life on Earth More Than Once? – #365papers – 2018 – 36

Grimm and Marchi, 2018, Direct thermal effects of the Hadean bombardment did not limit early subsurface habitability: Earth and Planetary Science Letters, v. 485, p. 1-8.

What’s it about?

The first billion years or so of Earth’s existence was marked by repeated bombardment of the planet by various asteroids, and even planetessimals. It is thought that this bombardment would superheat the Earth’s surface and kill any life that may have started to develop there. This study shows that, while the heating was extreme, there were still places that were protected from life-killing heat. Continue reading