Birds are a type of theropod dinosaur. Ruben is hardly world-respected or esteemed - his research re
Birds are a type of theropod dinosaur. Ruben is hardly world-respected or esteemed - his research relies almost entirely on outdated, disproven models (seriously, he once based an argument on tail-dragging T. rex). Longisquama’s integument only superficially resembles feathers, with no evidence of the actual structure of feathers (unlike dinosaur feathers, which do preserve this). Metabolic studies have repeatedly shown theropods to have been warm-blooded. Longisquama bears almost no resemblance to birds, whereas non-avialan theropods are so similar to early birds that the two can’t be told apart (see also: Archaeopteryx gaining and losing bird status every other week). Many non-avian theropods did have wings, but didn’t use them to fly, as there are many other uses for wings (including display, covering eggs, WAIR, and RPR). Theropods could potentially leap from trees, but nonetheless bird flight almost certainly evolved ground-up. Gliding animals, as a general rule, don’t evolve flight, but just become better gliders (and Longisquama’s gliding ability is questionable at best). -- source link