About Penny

Scientist (Paleontology, Geochemistry, Geology); Writer (Speculative and Science Fiction, plus technical and non-technical Science); Mom to great boy on the Autism spectrum; possessor of too many hobbies.

Who Did It First? Sponges or Comb Jellies? #365papers – 2017 – 83

#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

Are Photos Enough to Name a Species – #365papers – 2017 – 82

#365papers for March 23, 2017

Garraffoni and Frietas, 2017, Photos belong in the taxonomic Code: Science, v 355, p. 805

Gutierrez and Pine, 2017, Specimen collection crucial to taxonomy: Science, v. 355, p. 1275.

What’s this about?

The International Code for Zoological Nomenclature lays out the requirements for naming a new species of animal. Included in this this the requirement of a preserved specimen Ithe type) to be kept at a museum for reference. Garraffoni and Frietas argue that for specimens that don’t preserve well (that is, they break down and can’t be effectively studied after preservation), that a photograph or photographs should stand in instead of a preserved specimen. Gutierrez and Pine argue back that even if a specimen is reduced to goo, it should still be required if only for the possibility of DNA preservation. Continue reading

Everything You Know About Dinosaurs Is Wrong – #365papers – 2017 – 81

#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

Birth of the Amazon River – #365papers – 2017 – 80

#365papers for March 21, 2017

Hoorn, Bogota-A, Romero-Baez, Lammertsma, Flantua, Dantas, Dino, Carmo, and Chemale, 2017, The Amazon at sea: Onset and stages of the Amazon River from a marine record, with special reference to Neogene plant turnover in the drainage basin: Global and Planetary Change.

What’s it about?

The authors of this paper use data from an ocean core collected in the delta of the Amazon River to determine when the Amazon River began to deposit sediments into the ocean and also when it began to carry sediments all the way from the Andes Mountains. Continue reading

Midges Versus Pollen for Understanding Past Climate – 365papers – 2017 – 79

#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

Hypercarnivory, Tooth Development, and Evolutionary Dead Ends – #365papers – 2017 – 78

#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

Putting All the Data Together Makes a More Complete History – #365papers – 2017 – 77

#365papers for March 18, 2017

Feakins, Levin, Liddy, Sieracki, Eglinton, and Bonnefille, 2017, Northeast African vegetation change over 12 m.y.: Geology, v. 41, p. 295-298.

What’s it about?

The authors combine pollen and isotopic data from fossil leaf waxes from an ocean core with soil carbonate data from northeast Africa to better understand the origin and composition of grasslands in northeast Africa over the last 12 million years. Continue reading

Global Warming; Shrinking Mammals – #365papers – 2017 – 76

#365papers for March 17, 2017

D’Ambrosia, Clyde, Fricke, Gringerich, Abels, 2017, Repetitive mammalian dwarfing during ancient greenhouse warming events: Science Advances, v. 3, e1601430.

What’s it about?

Rapid global warming in Earth’s past had occurred more than once. The most commonly studied episode occurred 55 million years ago, at the boundary between the Paleocene and Eocene epochs (Paleocene Eocene Thermal Maximum, PETM). Several other episodes have happened, including the ETM2 and H2 episodes which are discussed in this paper.

Dwarfing of mammalian species has been documented at the PETM. This paper shows dwarfing of mammals also occurred at the ETM2. Continue reading

How Soil Carbonate Can Tell Us About Climate – #365papers – 2017 – 75

#365papers for March 16, 2017

Cerling, T.E., 1984, The stable isotopic composition of modern soil carbonate and its relationship to climate: Earth and Planetary Science Letters, v. 71, p. 229-240.

What’s it about?

This paper discusses in detail how isotopes of carbon and oxygen in carbonate minerals that form in soils are related to that of plant biomass (carbon) or local precipitation (oxygen). Continue reading

Rocks and Fossils in the Uinta Basin, Getting it in Order – #365papers – 2017 – 74

#365papers for March 15, 2017

Townsend, Friscia, and Rasmussen, 2006, Stratigraphic distribution of upper middle Eocene fossil vertebrate localities in the eastern Uinta Basin, Utah, with comments on Uintan biostratigraphy: The Mountain Geologist, v. 43, p. 115-134.

What’s it about?

This paper is a synthesis of over 100 years worth of research in the Uinta Basin, making a huge effort to sort out how the rocks and fossils correlate and to get everything in the correct chronologic order. Continue reading