Category Archives: Paleontology

#365papers for March 25, 2017

Harjunmass, Seidel, Kakkinen, Renvoise, Corfe, Kallonen, Zhang, Evans, Mikkola, Salazar-Ciudad, Klein, and Jernvall, 2017, Replaying evolutinary transitions from the dental fossil record: Nature, v, 512, p. 44-48.

What’s it about?

This paper considers the complex shape of rodent molars. They show through gene manipulation how the complex rodent tooth came from a simpler, basic mammal shape. All that was required was to change the timing and duration of a single gene.Continue reading “Evolving Teeth with Single Genes – #365papers – 2017 – 84”

#365papers for March 24, 2017

Simion, Philippe, Baruain, Jager, Richter, Di Franco, Roure, Satoh, Queinnec, Ereskovsky, Lapebie, Corre, Delsuc, King, Worheide, and Manuel, 2017, A large and consistent phylogenomic dataset supports sponges as the sister group to all other animals: Current Biology, http://dx.doi.org/10.1016/j.cub.2017.02.031

What’s it about?

There is interest in which, of the most simple multicellular animals that live today, were the first to appear. Which are the most primitive? Which are ancestral to all other multicellular animals? Sponges and comb jellies are the simplest, most primitive animals alive today. Which came first? This paper provides new results suggesting sponges came first.Continue reading “Who Did It First? Sponges or Comb Jellies? #365papers – 2017 – 83”

#365papers for March 22, 2107

Baron, Norman, and Barrett, 2017, A new hypothesis of dinosaur relationships and early dinosaur evolution: Nature, v. 543, p. 501-506.

What’s it about?

Every person who has learned much about dinosaurs knows that dinosaurs are divided into two groups: the saurischians (lizard-hipped) and the ornithischians (bird-hipped). They also know that modern birds are actually saurischians dinosaurs, not ornithischians like you would think.

Now, based on what these authors have found, every person who knows the above things are now WRONG.Continue reading “Everything You Know About Dinosaurs Is Wrong – #365papers – 2017 – 81”

#365papers for March 20, 2017

Samartin, Heiri, Joos, Renssen, Franke, Bronnimann, and Tinner, 2017, Warm Mediterranean mid-H0locene summers inferred from fossil midge assemblages: Nature Geoscience, v. 10, p. 207-212.

What’s it about?

Many global climate records show an episode of warming between 9000 and 5000 years ago. However, in the eastern Mediterranean region, the usual tools used to estimate temperature (in this case pollen) suggested that this was a cooler interval. The authors use fossilized larval chironomids (non-biting midges) found in lake deposits as another means to estimate summertime temperatures. The midges do show the expected warmth.Continue reading “Midges Versus Pollen for Understanding Past Climate – 365papers – 2017 – 79”

#365papers for March 19, 2017

Sole and Ladeveze, 2017, Evolution of the hypercarnivorous dentition in mammals (Metatheria, Eutheria) and its bearing on the development of tribosphenic molars: Evolution & Development, v. 19, p. 56-68.

What’s it about?

This paper discusses the teeth of carnivorous mammals, in particular the carnassials, or cutting teeth, characteristic of a meat-eating diet. These are the long, bladelike teeth toward the back of a dog or cat’s jaw, that come together with a scissor-like action to snip off bits of meat. Mammals from many different groups (including marsupials) have developed carnassial teeth.

The degree to which these teeth are blade like or still possess some of the crushing and puncturing features of ancestral mammals is an indication of how dependent on meat the mammal is. Cats, for example, lack the crushing and puncturing structures and are thus ‘hypercarnivores.’ Dogs in contrast, still have these ancient structures and are known to have a broader, more flexible diet.Continue reading “Hypercarnivory, Tooth Development, and Evolutionary Dead Ends – #365papers – 2017 – 78”