Papers of Today

Yesterday suffered from a lack of movies. Articles and scholarly papers, though, are another story. As with many fossil birds and new species that defy even the smallest portion of our perceived established knowledge there is a great deal of research conducted to determine where and how that fossil fits into the history of life. Sapeornis is no different. There are papers that describe the anatomy of Sapeornis (namely the original naming and describing article), individual species of the genus, and differences across life history. The most interesting paper, to me of course, that the search turns up is discussing the lack of key sternal elements that birds use to achieve powered flight. Zheng et al. 2014 discusses Anchiornis in addition to Sapeornis but the most important set of facts here is that these two genera from China are lacking elements considered to be of particular importance to flight. The abstract is written such that it sounds as though these animals entirely lack a sternum, which seems somewhat unlikely. The paper, however reveals that this feature was not so much absent as it was not ossified, instead existing as a cartilaginous structure in the most primitive birds and their closest dinosaur ancestors.