Category Archives: Paleontology

The End-Guadalupian Mass Extinction, Pyrite, and Sulfur Isotopes – #365papers – 2017 – 2

#365papers – January 2, 2017

Wei, Wei, Qiu, Song, Shi, 2016, Redox conditions across the G-L boundary in South China: Evidence from pyrite morphology and sulfur isotopic compositions: Chemical Geology, v. 440, p. 1-14.

What’s it about?

This paper presents evidence that marine anoxia (lack of oxygen in ocean water) may be the cause of the end-Guadalupian (middle Permian) mass extinction, using the appearance of pyrite (a reduced-iron mineral, FeS2), the shape and structure of pyrite, and isotopic values of sulfur to show this.Continue reading “The End-Guadalupian Mass Extinction, Pyrite, and Sulfur Isotopes – #365papers – 2017 – 2”

Dinosaur Tail Feathers in Amber – #365papers – 2017 – 1

#365papers – January 1, 2017

Xing, McKellar, Xu, Li, Bai, Persons, Miyashita, Benton, Zhang, Wolfe, Yi, Tseng, Ran, and Currie, 2016, A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber: Current Biology, v. 26, p. 3352-3360.

What’s it about?

Part of a dinosaur tail was found in Burmese amber and had bones on the inside and feathers on the outside. This dinosaur was a small theropod, a group that also includes Tyrannosaurus rex.Continue reading “Dinosaur Tail Feathers in Amber – #365papers – 2017 – 1”

… In Which the Author Jaws About Ears

So here’s the thing…

We all know that the jaw joint is basically a hinge. The lower jaw pivots at this point to open and close the mouth. For most animals, the lower jaw is a solid piece that contains teeth that works against the solid upper jaw that also has teeth.

Every animal that has a jaw has the same joint, between the articular bone in the lower jaw and the quadrate bone in the upper jaw. Fish are like this. Frogs, lizards, snakes, crocodiles, birds, turtles…. Everything.

Except Mammals. Naturally.Continue reading “… In Which the Author Jaws About Ears”

Find Me an Amniote! Stat!

Amniotes are important. You are an amniote (I promise). Birds are amniotes. Turtles are amniotes. Crocodiles are amniotes. Dinosaurs were amniotes. Dogs and cats are amniotes. Lizards are amniotes.

But amphibians (like the spring peepers that have been so noisy of late) are not amniotes. Fishes aren’t amniotes either.Continue reading “Find Me an Amniote! Stat!”

Name that Species!

In biology and paleontology, species is everything. It’s a point of pride to have named a new species, just like I feel about naming Fractinus palmorem.

In your middle-school science class, you probably learned that a species is defined as organisms that can reproduce, yielding living and fertile offspring, and that do so naturally. This is the biological species concept. It works great, but for fossils, this idea doesn’t work so well. We can’t observe behavior or reproductive success in the fossil record.

Though we have this strict definition, for practical purposes we recognize different species because members of a species look similar to each other. With fossils, comparing overall ‘looks’ or morphology. Using this method, we can consider fossil species as morphological species.Continue reading “Name that Species!”