Early birds flew on four wings
...reported in Nature:
Birdlike dinosaurs, such as Microraptor and Sinornithosaurus, are known to have had long, sturdy feathers on their hindlimbs. But until now, researchers were not sure whether the earliest birds had already abandoned this extra plumage when they emerged to take to the Cretaceous skies over 100 million years ago.
The researchers, led by Xing Xu, a palaeontologist at the Institute of Geology and Paleontology in Shandong, China, found evidence of feathers on the hindlimbs of 11 basal bird specimens (gathered from the Lower Cretaceous Jehol Group in China)3. On some of the individuals, these feathers appeared to be veined flight feathers that stood perpendicular to the leg bones, similar to those in the basal bird Archaeopteryx.
One specimen, attributed to the Sapeornis genus, had at least one hindlimb feather longer than 50 millimetres. Feathers on the feet were shorter, but were still more than 30 millimetres long.
"It is amazing that so many early birds had large leg feathers," Xu says. The first winged dinosaurs were discovered just 10 years ago, he notes. These findings "are important for both flight origin and feather evolution".
The hind limb plumage has been reported before, but this analysis "provides solid evidence for the existence of enlarged leg feathers on a variety of basal birds, suggest that extensively scaled feet might have appeared secondarily at an early stage in ornithuromorph evolution, and demonstrate a distal-to-proximal reduction pattern for leg feathers in avialan evolution."
Monoplane dinosaurs, biplane dinosaurs, what's next ... helicopters?
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omg is he fast! I'm sooo tired! 
I have the 2 1/2 y/o and his 11 month old brother, two half days, every week. The baby can walk. I run the whole time.
The older one is so curious right now, about all things on my dresser top. I think the other grandma hides candy? He's looking in all the small keepers with lids, for whatever, he can see. So bright and far too quick.
Thank goodness we can spend some time outdoors, now. We aren't trapped in the house. Crocuses are up. Sun is out!
And Dinosaur Train at 10:00. My favorite.
The youngest is almost obsessed with Curious George and Scooby. He doesn't have tv at his home and I only have antenna, but do get PBS, and he watches all those shows when here. He thinks I can make them put on whatever he wants on tv, but he's learning.
I don't know how old you are, but I am near 55 and feel very old most days after chasing that little stinker. He is great company on errands though! I don't spoil them one bit. 
Time goes so quickly and too soon they move on to their own lives and friends. The twelve year old is at that point and he's been the best 'date' I've had on the weekends in twenty years!
I intend to just enjoy them while I can and know you are too. 
You are to them. I have fond memories of my dear grandma. She was so small and sweet and worked so hard all her life.
she retired at 65. I never heard her say a mean word about, or to, anyone, ever. The stories of her and my grand-aunt playing piano for booze in speakeasys were hysterical. They were feminists before anyone ever heard of one.
I wouldn't make it without my dear grandsons in my life. They are great kids!