As mentioned previously, longirostravisines, unlike most other enantiornitheans, lacked claws on all three of their manual digits, a trait apparently acquired separately of the Carinatae (Ichthyornis + modern birds). In the last post I speculated that this might have reflected a distinct flying (or at least landing) style. But how much do we really know about longipterygid flight?
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| Fig. 10 from Close & Rayfield 2012, click to big it up. Note the three general clusters of continuous-flapping (red), soaring and flightless (yellow and gray), and bizarro enantiornithean style (green). |
In their recent paper, Close & Rayfield attempted to correlate wishbone (furcula) shape with flight style. Many enantiornitheans in the analysis plotted together in a cluster well separated from modern birds, but close to basal avialans like Confuciusornis which are usually presumed to have been gliders. Oddly, in the Close & Rayfield figure reproduced above, Rapaxavis (no. 103), a longirostravisine, clusters with the weirdo enantiornithean-style fliers, while more basal longipterygid Longipteryx (no. 98) groups with continuous-flapping fliers and is marked as an ornithurine (something seems off here).
In another recent open-access paper on Mesozoic bird flight styles, Wang et. al (2011), using wing element and primary feather length ratios, found Longirostrisavis to be a continuous-flapping flier, and Longipteryx either a continuous-flapping or a flap-gliding flier, roughly the opposite result of the Close & Rayfield furcula-based analysis.
The fact that two independent analyses using two distinct methods produced different results probably does not bode well for the precision of either method. Clearly, we need to figure out better methods to more reliably tests flight styles in extinct birds.
Hi theres a paper that just came out on the flight of Miroraptor with hinds wings! im a artist and im just getting into sculpting with scupley clay is it reasonable to put ''large'' leggs feathers on enantiornithines?? How else can they stear with ''no tail feathers''? please reply dan
ReplyDeleteSome degree of steering may have been provided by the relatively advanced alula. In modern birds, the tail is mostly used for braking and providing mid-air stall, rather than for steering. According to the paper you're talking about, Microraptor actually had much *greater* steering ability than most modern birds, probably necessary for its unique ecology and flight style (un- or poorly-powered flight through very dense forest). Presumably, most enantiornitheans simply did not need this level of steering control, or achieved it in a different way using only the wings. There is one specimen of an unnamed enant with relatively long leg feathers, but they're nowhere near as long or specialized as those in Microraptor and they do not anchor to the tarsus or foot, they are merely long leg feathers as in some modern birds like hawks. While these may have been some use in flight, it doesn't look like they're analogous to the hind wings of microraptorians.
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