Monthly Archives: April 2017

Duane Froese, University of Alberta, presents new research on the extinction of mammoths and other megafauna from Arctic North America.

https://www.youtube.com/watch?v=3Rr2jcx6OFA

A new study (that included Nicholas Pyenson from the Smithsonian and an Affiliate Curator Burke Museum) looked at the origin of baleen and how modern toothless baleen whales evolved from early toothed forms without baleen.  Baleen filter plates in whale jaws are unique among mammals, but are made of keratin similar to horns and hoofs.  The researchers reviewed the fossil evidence and looked at four possible evolutionary scenarios in which whales had both teeth and baleen at the same time or lost their teeth before they evolved baleen.  Other studies have suggested that suction feeding by toothed ancestors may have led to the development of baleen. The new study proposes that a toothless suction feeding stage may have come before baleen developed. Unfortunately, the embryonic development of tooth buds and baleen in modern whales is still not well understood.

Carlos Mauricio Peredo, Nicholas D. Pyenson and Alexandra T. Boersma (2017) Decoupling Tooth Loss from the Evolution of Baleen in Whales. Frontiers of Marine Science  4: Article 67 https://doi.org/10.3389/fmars.2017.00067

http://journal.frontiersin.org/article/10.3389/fmars.2017.00067/full

A team of researchers in Britain did a new analysis of hundreds of dinosaur skeletons and  have concluded that the current classification of dinosaurs into two major groups called the Saurischia (“lizard-hipped”) and Ornithischia (“bird-hipped”), first proposed in 1888, is not correct.  Read More →

Paleontologists use the German term Lagerstätte [storage place] for fossil sites with exceptional preservation and abundant fossils. Such deposits are rare worldwide. Stonerose in Washington state is considered an example of a Lagerstätte for plant fossils.  Now a new Lagerstätte for marine animals (invertebrates and vertebrates) has been found at Ya Ha Tinda in Alberta, Canada, and dates from the same time period as similar marine fossil sites in Italy, Germany, and  Great Britain. The special preservation (including soft tissues) may be the result of low oxygen levels in the water at the time, preventing decay before the animals were buried in sediment.

Rowan C. Martindale, Theodore R. Them II, Benjamin C. Gill, Selva M. Marroquín, and Andrew H. Knoll (2017) A new Early Jurassic (ca. 183 Ma) fossil Lagerstätte from Ya Ha Tinda, Alberta, Canada. Geology 45:. 255-258, doi:10.1130/G38808.1 http://geology.gsapubs.org/content/45/3/255.abstract