Dinosaurs extinct, birds survived


Dinosaurs, birds and extinction. Timeline adapted from S.L. Brusatte, J.K. O’Connor and E.D. Jarvis/current biol. 2015

From Science News:

Some lucky birds escaped dino doomsday

Feathers, wishbones and more were a dino thing before they were a bird thing

By Susan Milius

2:30pm, January 25, 2017

The flight stuff

Some traits made famous by modern birds first popped up in dinosaurs that met unfortunate ends. This diagram shows when traits like standing on two legs, feathers and wishbones emerged in the bird/dino part of the tree. Numbers one through four correspond to examples of trailblazing birdlike dinosaurs and early birds highlighted in the interactive slideshow below.

The asteroid strike (or was it the roiling volcanoes?) that triggered dino doomsday 66 million years ago also brought an avian apocalypse. Birds had evolved by then, but only some had what it took to survive.

Biologists now generally accept birds as a kind of dinosaur, just as people are a kind of mammal. Much of what we think of as birdlike traits — bipedal stance, feathers, wishbones and so on — are actually dinosaur traits that popped up here and there in the vast doomed branches of the dino family tree. In the diagram above, based on one from paleontologist Stephen Brusatte of the University of Edinburgh and colleagues, anatomical icons give a rough idea of when some of these innovations emerged.

One branch of the dinosaur tree gradually turned arguably avian (in the Avialae/Aves group) by about 165 million to 150 million years ago. That left plenty of time for bona fide birds to diversify before the great die-off.

The bird pioneers included the once widespread and abundant Enantiornithes, or “opposite birds.” Compared with modern birds, their ball-and-socket shoulder joints were “backwards,” with ball rather than socket on the scapula.

These ancient alt birds may have gone down in the big extinction that left only fish, amphibians, mammals and a few reptile lineages (including birds) among vertebrates. There’s not a lot of information to go on. “The fossil record of birds is pretty bad,” Brusatte says. “But I think those lineages that go up to the red horizontal line of doom in my figure are ones that died in the impact chaos.”

Advertisements

14 thoughts on “Dinosaurs extinct, birds survived

  1. Pingback: Dinosaurs’ horns, crests, why? | Dear Kitty. Some blog

  2. Pingback: Horse evolution, new study | Dear Kitty. Some blog

  3. Pingback: Computer game on evolution of bird flight | Dear Kitty. Some blog

  4. Pingback: Feathered dinosaurs, new research | Dear Kitty. Some blog

  5. Pingback: Dinosaurs extinct, buckthorn flowers survived | Dear Kitty. Some blog

  6. Pingback: Bus-sized pliosaur discovery in Russia | Dear Kitty. Some blog

  7. Pingback: Mass extinction of wildlife threatens | Dear Kitty. Some blog

  8. Pingback: First fossil botfly discovery | Dear Kitty. Some blog

  9. Pingback: Dinosaurs extinct, frogs survived | Dear Kitty. Some blog

  10. Pingback: Dinosaur extinction and bird evolution | Dear Kitty. Some blog

  11. Pingback: Ticks drank dinosaur blood | Dear Kitty. Some blog

  12. Pingback: Human-sized fossil penguin discovery | Dear Kitty. Some blog

  13. Pingback: What makes dinosaurs dinosaurs? | Dear Kitty. Some blog

  14. Pingback: Birds survived dinosaurs, other birds extinct with them | Dear Kitty. Some blog

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.