Category Archives: Science

#365papers for March 30, 2017

Bailleul and Holliday, 2017, Joint histology in Alligator mississippiensis challenges the identification of synovial joints in fossil archosaurs and inferences of cranial kinesis: Proceedings of the Royal Society B, v. 284: 20170038

What’s it about?

In the past, when paleontologists have observed joints between bones, especially in the skull, that possess smooth surfaces, an assumption as been made that these joints are flexible. Flexible joints in the skull result in cranial kinesis, where the head can be deformed as exemplified by modern snakes as they consume prey much larger than their own heads. The authors show, through study of modern alligator skulls, that smooth joint surfaces don’t necessarily mean that a joint was movable, and that detailed study of the structure of the bone itself is needed to know if a joint could bend or not.Continue reading “Not All Joints Are Flexible – #365papers – 2017 – 89”

#365papers for March 29, 2017

Mallon, 2017, Recognizing sexual dimorphism in the fossil record: Lessons from nonavian dinosaurs: Paleobiology, DOI:10.1017/pab.2016.51

What’s it about?

In paleontology, we define species by what they look like. This can be problematic if males and females of one species look markedly different from one another. Some authors have claimed to see sexual dimorphism, the difference in shape between males and females in a species, based on size. Here, the author shows that it is essentially impossible with the fossil record to make such determinations.Continue reading “Telling the Boys from the Girls in Fossils – #365papers – 2017 – 88”

#365papers for March 28, 2017

Getty, Aucoin, Fox, Judge, Hardy, and Bush, 2017, Perennial lakes as an environmental contol on theropod movement in the Jurassic of the Hartford Basin: Geosciences, v. 7, doi:10.3390/geosciences7010013

What’s it about?

This is a paper about dinosaur tracks. Specifically, it discusses how dinosaur tracks, when they all seem to go in the same direction, are used as evidence that dinosaurs traveled in herds. Here, they show that the reason why the dinosaurs were all going the same way has to do with a lake near by, and not that the dinosaurs were all traveling together.Continue reading “When Water Stopped the Dinosaurs – #365papers – 2017 – 87”

#365papers for March 26, 2017

Williamson, Brusatte, Secord, and Shelley, 2016, A new taeniolabidoid multituberculate (Mammalia) from the middle Puercan of the Nacimiento Formation, New Mexico, and a revision of taeniolabidoid systematics and phylogeny: Zoological Journal of the Linnean Society, v. 177, p. 183-208.

What’s it about?

This paper discusses a group of large multituberculates that lived during the Paleocene (approximately 66 – 55 million years ago). Multituberculates, alas, are extinct, but resembled rodents in many ways. They were distinguished by their multi-cusped teeth (that looked a little like Legos) and blade-like premolars.

Taeniolabidoids would have been squirrel to marmot sized – as a group much larger than most other multituberculates.Continue reading “Some New Mammals from Ancient New Mexico – #365papers – 2017 – 85”

#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”