The Earth Story

Most of us aren't going to be able to fly anywhere any time soon, but here's a view of what flights used to look like out the front window of a plane. This nighttime voyage on an Air France flight starts off in Chicago and flies over the Great Lakes and eventually Montreal Canada before heading out on the rest of its trip.

Yi qi

Common name: Batdino Size: Pigeon sized (10cm). Age: Mid Jurassic (160 million years ago) Geographic range: China/Mongolia. Liked: Flying/gliding. Disliked: Being eaten. Taxonomy: Animalia > Chordata > Dinosauria > Theropoda>Scansoriopterygidae>Yi>qi

The Jehol and Daohugou Biota of north eastern China (see http://on.fb.me/1cViPit and http://on.fb.me/1Hnu8YF) have repeatedly stunned palaeontologists over the last couple of decades with their well preserved 160 and 130 million year old ecosystems. The time period covered by the two formations spanned the transition between feathered dinosaurs and birds, amongst other things, and the exceptional preservation of these fossilised organisms has brought us many feathers, mammalian fur and other rarities to study that are usually not preserved in fossilisation.

Yi qi comes from the older rocks of the Daohugou formation, some 160 million years old. These are the remnants of tree shaded lakes that were periodically covered in huge volumes of volcanic ash from pyroclastic flows, each killing a wide diversity of animals and shunting them into the lake beds, where the fine grained ash preserved them in near perfect detail. Only one geologically flattened partial specimen exists, the size of a medium bird that was maybe a tree dweller. The name comes from the Chinese for 'strange wing'.

Several features of its anatomy are unique. Its elongated third finger had a membrane of sliding skin and a never before seen long bony strut attached at the wrist, resulting in a bat shaped wing arrangement. Whether a newly evolved wrist bone or a ossified cartilage, the feature is very odd. The critter was a feathered therepod, whose plumes resembled quills or paintbrushes ( for an idea of what these dino feathers looked like, see my past posts of them preserved in amber, Jurassic park style, at http://on.fb.me/1DTZQdF and http://on.fb.me/1QpTFac). They were covered all over and quite dense, up to 6 cm long. Some of the bat like membrane was also preserved, and no flight feathers were present. They analysed the melanosomes for colour and found the feathers were black like a crow's and brown on the head.

The resemblance to a bat would be an example of convergent evolution, where different animals from widely varied evolutionary backgrounds take on a similar shape, such as tuna fish, dolphins (mammals) and ichthyosaurs (reptiles). It also suggests that flight evolved several times using different means in the dinosaurian and early bird lineages with maybe several groups transitioning from gliding to powered flight. It is also a transitional form between feathered dinos evolving into birds and the unrelated pterosaurs, with their more bat like wing structures. This is certainly an interesting and unusual twig on the great tree of expressed nucleic acids that we call life, and, incidentally, the dinosaur with the shortest name of all.

Loz

Image credit: graphic Dinostar Co. Ltd., photos Zang Hailong http://bit.ly/1EYblI0 http://bit.ly/1EDJFq6 http://bit.ly/1GI1QNp http://bit.ly/1GwyNXL

Plane window timelapse on a flight from Louisville, Kentucky to Las Vegas, Nevada. Amazing how the landscape and the weather patterns change out the window as a plane goes. 

Pilot’s view out over Greenland

The Origin of Avian Flight: The Great Debate

Avian flight is a remarkable evolutionary feat. But, where did it begin? Scientists are still stumped. Due to the lack of historical data that is available, it is very difficult for researchers to define when and how it began. There are two main competing hypotheses collectively known as top-down vs. bottom-up: 1) Top-down (aka: From Trees Down): scientifically known as the Arboreal hypothesis. The arboreal hypothesis begins with a tree-dwelling, feathered dinosaur/bird species. This species climbed tree trunks and leaped between them to catch prey and/or avoid predators (comparable to a flying squirrel). Flight in this species arose in a series of evolutionary adaptions that increased gliding ability to increase distance, then flapping and controlled tail feathers to increase manoeuvrability while gliding, and then finally, full flapping allowing for constant flight. These adaptions would have been characteristics such as decreased body mass, hollow bones, stiffer feathers, etc. This hypothesis can be supported by some evidence, such as the anatomy of Archaeopteryx (one of the earliest known bird/dinosaur species. See attached photo), which had feet similar to today's tree-perching birds.

2) Bottom-up (aka: From Ground Up): scientifically known as the Cursorial hypothesis. This hypothesis was later developed as a counter to the top-down theory. It suggests that the long neck, long legs, and stiff tail of Archaeopteryx suggests that it was a ground-dwelling sprinting species. To maintain good balance, individuals would spread their wing-like arms and use them in conjunction with the stiff tail to be more agile runners, while also creating lift to conserve energy. The lift would also allow Archaeopteryx to leap long distances to attack prey. Over time, feathers became stiffer and the body became lighter to create additional lift, which eventually resulting in wing flapping. Eventually Archaeopteryx could lift off the ground and fly.

Both hypotheses are riddled with assumptions and disagreements on the interpretation of avian ancestors' anatomy and morphology, which is why it continues to be debated.

Which hypothesis do you support? Debate below! (I'm curious)

~Rosie

Image source: http://abacus.bates.edu/acad/depts/biobook/Pal10pix.htm

Reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4992707/

Gopro view from a wingsuit flight over the Wasatch Mountains, Utah. Watch for the pilot’s shadow! (do you call them pilots? I have no idea!)

marshall__miller

Chasing #shadows down #wangsoverwasatch summer edition.

The volcano is practically posing in this shot

Original caption:

360 degree gopro camera view flying through one of the world’s great mountain ranges. Original caption:

Computer generated but really cool! A simulated flight amongst the Mesas and Buttes of Monument Valley, Navajo Nation, Utah and Arizona