Concornis

Concornis is a genus of enantiornithean birds which lived during the early Cretaceous period, in the late Barremian age about 125 million years ago. Its remains are known from the Calizas de La Huérgina Formation at Las Hoyas, Cuenca province, Spain. The single known species, Concornis lacustris, was described from the remains of one fairly complete individual skeleton.

Concornis is a genus of enantiornithean birds which lived during the early Cretaceous period, in the late Barremian age about 125 million years ago. Its remains are known from the Calizas de La Huérgina Formation at Las Hoyas, Cuenca province, Spain. The single known species, Concornis lacustris, was described from the remains of one fairly complete individual skeleton. ==Classification== Upon its initial description it was believed to be more primitive than Enantiornithes; In 1992, this group was poorly known and, as the primitive Iberomesornis was not yet considered to belong there either, contained only very advanced taxa. A wave of Chinese paleontological discoveries in the mid 1990s led to the group becoming much more well known, and the placement of C. lacustris within it was eventually verified. In fact, despite its early age, C. lacustris seems to be a fairly derived member of Enantiornithes. A relationship with Sinornis and Cathayornis has been suggested mainly based on a peculiarly autapomorphic sternum. There is a keel that is Y-shaped and small compared to that of modern birds. The end of the sternum also bears deep notches. A 2008 analysis placed Concornis in the family Avisauridae due to several features of the tibiotarsus (shinbone and upper ankle bones). Under this classification, Concornis is the oldest (and the most complete) member of the family. ==Paleoecology== The habitat and habits of Concornis lacustris are by and large conjectural. Its legs and flight apparatus suggest it was a truly multifunctional generalist bird able to bound through vegetation, run on the ground, and fly equally well. Compared to living birds adapted to each of these ecological niches, it would have certainly been inferior. It was found in an aquatic environment, suggesting it occupied at least partly a "shorebird" niche, and given its size would presumably have fed on small invertebrates like insects or crustaceans. There were terrestrial predators around in its habitat - including its non-avialan theropod relatives and crocodilians - from which Concornis would have found it far easier to fly up to some branch rather than to run away. A 2018 study analyzed the proportions of Concornis and Eoalulavis (a contemporary enantiornithean) to determine the optimal flight pattern for those genera. The study found that they likely engaged in bounding flight, a form of flight popular among modern small and short-winged birds. A bird engaging in bounding flight alternates between upward-thrusting flaps and short dives with folded wings. The study also found that they were capable of continuous flapping flight, but were likely unable to glide due to having a high body mass to wingspan ratio. The study concluded that Eolalulavis, Concornis, and likely many other enantiornitheans alternated between the fast bounding flight and the slower but more efficient flapping flight depending on the circumstances, similar to modern songbirds and woodpeckers. ==References==

Text derived from https://en.wikipedia.org/w/index.php?oldid=1376555129 under CC BY-SA 4.0; modifications have been made.