Extinction and the Rise of Dinosaurs - What Will the Microvertebrates Tell Us?

Brian Switek has a great year end article (based mainly on the recent Allen et al., study in Palaeontology) regarding the loss of most pseudosuchian groups in the end-Triassic extinction and discussion on why the dinosaurs were mostly unaffected.

According to their findings body size was not a factor; however, there are not too many data regarding Middle Triassic - Early Jurassic microfaunas. My intern, colleague and Virginia Tech grad student Ben Kligman is adding to this information. Ben started a couple of years ago at Petrified Forest National Park looking at a new microsite in the Blue Mesa Member of the park. This unit and roughly the same horizon had been the subject of several previous microvertebrate studies that despite being nearly two decades apart had generated roughly the same results, a lot of teeth and scales that could only be assigned to broad taxonomic levels. Thus, I was not enthusiastic about this at first. However, Ben tackled this new site with gusto and developing a new sampling technique with the help of PEFOs lead preparator and curator Matt Smith, very quickly built a sample of over 100 different morphotypes. Even more important this new technique allowed preservation of relatively complete jaw elements.

<i>Palacrodon browni</i> from the Chinle Formation of Arizona.
From Kligman et al 2018. Acta Palaeotologica Polonica 63(1).

Ben already has several publications about new these finds (Kligman et al., 2017; Kligman et al., 2018) and several more in the works. Furthermore, this research won the Student Poster Prize at the 2018 Society of Vertebrate Paleontology meeting. Ben is now sampling a wider stratigraphic range of sites and his work will help us further understand the effects of the end-Triassic extinction.