What if We’re Wrong About Placoderms? – #365papers – 2018 – 57

Zhu, Yu, Ahlberg, Choo, Lu, Qiao, Qu, Zhao, Jia, Blom, and Zhu, 2013, A Silurian placoderm with osteichthyan-like marginal jaw bones: Nature, v. 502, p. 188-193

What’s it about?

I reported on another paper with Zhu as lead author sometime last week. That paper provided evidence that certain dermal bones (the dentary and maxilla), traditionally viewed as synapomorphies for the crown osteichthyes may also be present in placoderms. This is the first paper in which Zhu reported this observation. Continue reading

Clay Keeps Records of Ancient Water – #365papers – 2018 – 56

Mix and Chamberlain, 2014, Stable isotope records of hydrologic change and paleotemperature from smectite in Cenozoic western North America: Geochimica et Cosmochimica Acta, v. 141, p. 532-546

What’s it about?

Smectite is a specific kind of clay mineral, common in volcanic ash. This kind of clay incorporates water during its formation, which, as the authors show, can provide a record of what surface water was like when the clay formed. Continue reading

Is Your Beer Making You Sick? – #365papers – 2018 – 55

Pradenas, Galarce-Bustos, Henriquez-Aedo, Mundaca-Uribe, and Aranda, 2016, Occurrence of biogenic amines in beers from Chilean market: Food Control, v. 70, 138-144

What’s it about?

Brewing beer is serious organic chemistry, and beer can have some not-really-healthy chemicals in them from various sources. The authors of this paper discuss the occurrence of amines (a type of biologically produced chemical) in beers produced in Chile that can, at high concentrations, have negative effects on the health of the beer drinker.

There are two general sources of these amines, either from microbial contamination (like small quantities of bacteria in the beer) or could have been present in the raw materials used to make the beer (barley, yeast, and hops). Continue reading

Plants and Animals Don’t Respond to Climate Change the Same Way – #365papers – 2018 – 54

Wing and Harrington, 2001, Floral response to rapid warming in the earliest Eocene and implications for concurrent faunal change: Paleobiology, v. 27, p. 539-563

What’s it about?

The Paleocene-Eocene boundary is marked by a period of rapid global warming and co-occuring changes in mammals in response to the warming, including the appearance of seemingly dwarfed species and the rise of important mammal groups like the hoofed mammals and primates. The authors here use fossilized pollen from rocks known to bracket the Paleocene-Eocene boundary and discuss the changes in plants during this important episode of climate change. Continue reading

The Value of Fossils from the Margins of Basins – #365papers – 2018 – 53

Muldoon and Gunnell, 2012, Omomyid primates (Tarsiiformes) from the Early Middle Eocene at South Pass, Greater Green River Basin, Wyoming: Journal of Human Evolution, v. 43, p. 479-511

What’s it about?

Much of this paper is a description of a new species of early primate, along with a description of the primate fauna from South Pass, Wyoming, which is on the edge of the Green River Basin. This particular fauna is important because it is on the edge of a geographical basin, so it includes a mixture of animals that prefer flat plains and those that prefer upland areas. Continue reading

How Do Teeth and Jaws in Placoderms Grow? – #365papers – 2018 – 52

Rucklin, Donoghue, Johanson, Trinajstic, Marone, and Stamponi, 2012, Development of teeth and jaws in the earliest jawed vertebrates: Nature, v. 491, p 748-752

What’s it about?

Using tomographic data, the authors tease the different growth stages of the lower jaws of placoderms apart and show that the development of teeth are separate from the development of the jaw bone itself. Continue reading

Whence Come the Teeth of Vertebrates? – #365papers – 2018 – 51

Smith, 2003, Vertebrate dentitions at the origin of jaws: when and how pattern evolved: Evolution & Development, v. 5, p. 394-413

What’s it about?

Smith presents an argument that all teeth in vertebrates share a common origin, even though they look remarkably different, using evidence from growth lines in fossils, as well as developmental studies of modern fishes to support this. Continue reading

Where, Oh Where Do the Ganglia Go (in Lampreys) – #365papers – 2018 – 50

Modrell, Hockman, Uy, Buckley, Sauka-Spengler, Bronner, and Baker, 2014, A fate-map for cranial sensory ganglia in the sea lamprey: Developmental Biology, v. 385, p. 405-416

What’s it about?

Fate-maps show where tissues in an embryo wind up in the adult. It is truly remarkable how cells move around in embryos. I mean, seriously.

In this case, the authors are tracing sensory ganglia, in particular, to branches of the trigeminal nerve: the ophthalmic (or profundal) and the maxillomandibular, which provide sensory functions to parts of the lips and mouth. Continue reading

Squids, and Octopodes, and Nautiluses, Oh My! – #365papers – 2018 – 49

Sanchez, Setiamarga, Tuanapaya, Tongtherm, Winkelmann, Schmidbaur, Umino, Albertin, Allcock, Perales-Raya, Gleadall, Strugnell, Smiakov, and Nabhitabhata, 2018, Genus-level phylogeny of cephalopods using molecular markers: current status and problematic areas: PeerJ v. 6, e4331

What’s it about?

Using DNA sequences, the authors sort out the evolutionary relationships among squids, octopuses, nautiluses, and cuttlefish. Continue reading

We Know Sea Level Rise is Getting Faster – #365papers – 2018 – 48

Nerem, Beckley, Fasullo, Hamlington, Masters, and Mitchum, 2018, Climate-change-driven accelerated sea-level rise detected in the altimeter era: Proceedings of the National Academy of Sciences

What’s it about?

Sea level is rising. In fact, it’s rising faster and faster. Using satellite data, the authors show that this is the case, even when variations from volcanic events and ‘ordinary’ ocean shifts (like El Nino) are taken into account. Continue reading