The Dinosaur Institute team recently returned from a three-week dinosaur dig in the Jurassic outcrops of Utah.
A new genus of Late Cretaceous diving bird was described and published in the online journal PLoS ONE by Drs. Alyssa Bell and Luis M.Chiappe of the Dinosaur Institute. Named in honor of NHM Trustee, Karen Hoffman, Fumicollis hoffmani is a Late Cretaceous loon-sized diving bird with specialized hindlimbs that helped propel it through the water in search of food. The specimen (UNSM 20030) was collected in 1937 by Harold Shepherd and George Sternberg for the University of Nebraska State Museum (UNSM) from the Smokey Hill Memberof theNiobrara Chalk Formation of Logan County Kansas; UNSM 20030 was misidentified as Baptornis advenus, a smaller, more primitive foot-propelled diver and remained so for 77 years untilthese uniquely adapted feet caught the eye of Dr. Alyssa Bell.
The Cretaceous Hesperornithiformes were one of the first lineages of Mesozoic birds discovered, in the 19th century. As a member of a group of highly derived diving birds, where 18 of the 23 named species are known from specimens consisting of fewer than 3 elements, Fumicollis hoffmani is significant in that it is one of the best preserved small hesperornithiforms known to science; it has over twenty elements preserved. Studies on the toe and ankle bones of this fossil suggest that these diving birds could exploit food resources too shallow for the larger, 5-foot-long Hesperornis regalis, and too deep for the smallest diver in this group, Baptornis advenus. This indicates that these contemporary foot-propelled divers had already established a high degree of ecological specialization, which helped them minimize competition for the same food sources. Furthermore, the anatomy of the new fossil, particularly how its shingled toe arrangement reduces drag while diving, help us further understand of the evolution of diving specializations in this ancient group of Late Cretaceous birds.
Title: "Identification of a New Hesperornithiform from the Cretaceous Niobrara Chalk and Implications for Ecologic Diversity among Early Diving Birds.
Authors: Authors: Bell, Alyssa K. and Luis M. Chiappe. Published: PloS ONE. 0.1371/journal.pone.0141690.
More than twenty paleontologists, molecular biologists, and computer programmers from five different countries have contributed to the development of The Fossil Calibration Database, a free, open-access resource that stores carefully vetted fossil data. The database was launched in February, and a scientific paper announcing the resource was published in the September issue of the journal Systematic Biology, and is freely available here: http://sysbio.oxfordjournals.org/content/64/5/853
The database is a result of over five years of work from an international team including Dr. Nathan Smith, an Associate Curator in the Dinosaur Institute. “Fossils are essential for understanding the timing of evolutionary events in life's history,” Dr. Smith said. "The temporal information associated with fossils can be used to calibrate 'molecular clocks,’ which allow us to answer diverse questions in biology, such as when certain groups originated, the speed at which genes are evolving, whether or not speciation and extinction rates have changed through time and how biodiversity has been shaped by climatic changes in Earth history.”
Since its launch in February, the site has logged 12,681 unique visitors, 92,279 page views and 189,652 total views. Science, a highly revered, leading journal of original scientific research, global news and commentary wrote an excerpt on the new database.
For more information on the database visit http://fossilcalibrations.org.
Climate and plant community instability may have prevented the success of dinosaurs in tropical latitudes during the Triassic Period, according to a new scientific paper published in the Proceedings of the National Academy of Sciences USA. Dr. Nathan Smith, an Associate Curator in the Dinosaur Institute, joined an international team — led by Dr. Jessica Whiteside of the National Oceanography Centre at the University of Southampton, and co-authors Sofie Lindström, Randall Irmis, Ian Glasspool, Morgan Schaller, Maria Dunlavey, Sterling Nesbitt, and Alan Turner — to study the Late Triassic environments and ecosystems preserved in the Chinle Formation of northern New Mexico.
The study found that the plants within the formation change from a seed fern-dominated system to a conifer-dominated system, and that individual plant groups repeatedly alternated from rare to common through time. Carbon isotope data suggest an overall arid environment, albeit one affected by strong environmental fluctuations between humid and arid conditions. Widespread fossil charcoal material suggests frequent wildfires during the Triassic, possibly due to environmental fluctuation that encouraged plant growth during humid periods and enhanced moisture loss during arid times. The results suggest that the fluctuations, accompanied by high atmospheric carbon dioxide, may have prevented widespread establishment of large herbivorous dinosaurs in tropical latitudes until the Jurassic Period because of unpredictable resource availability.
The paper and supplemental information are available here at http://www.pnas.org/content/112/26/7909
Read the Los Angeles Times article here: