Mammals family tree predates the dinosaurs

[Why Syzygy]

http://www.msnbc.msn.com/id/32194062/ns/technology_and_science-science/

By Jennifer Viegas

updated 12:09 p.m. CT, Wed., July 29, 2009

The world's first known tree-dwelling vertebrate has just been identified, according to a new study. The tiny, agile animal lived 30 million years before the first dinosaurs and was a distant relative of mammals, including humans.

More than 15 near-complete skeletons of the 260-million-year-old animal, named Suminia getmanovi, reveal that it was built for an arboreal lifestyle.

"As the first tree-climbing vertebrate, Suminia had very long fore and hind limbs, with especially long hands and feet," lead author Jorg Frobisch told Discovery News. (...)

[Heidi]

1. What?1?! That can't be right. The earth is only 6,000 years old.

[HysteryDiagnosis]

2. Suminia getmanovi

Italian mammals. Must be the wine that kept them going.

[On the Road]

3. I Had Never Heard of These Guys

the family tree keeps changing every few years. Next question is where these syanpsids came from--proto-amphibians?

[Why Syzygy]

4. Story reports this much ..

"Non-mammalian synapsids were formerly unofficially known as 'mammal-like reptiles,' but they are actually not at all reptiles, but are more closely related to mammals," Frobisch said, adding that Suminia indeed "is a distant relative of mammals."

Other Paleozoic synapsids included Edaphosaurus and Dimetrodon, which both looked somewhat like a cross between an iguana and a dinosaur with a boat sail tacked on its back.

[muriel_volestrangler]

5. It's not so much the family tree, as the names used for sections of it, that change

The word 'reptile' is becoming increasing problematic.

For instance, crocodilians are more closely related to birds than to other reptiles, since crocodiles and birds share a common ancestor (an 'archosaur') that the other reptiles don't. Go a bit further back and you get to a common ancestor for all existing reptiles (eg snakes and turtles too) as well as the birds. Go further back still and you get a common ancestor for all of those, and the synapsids, which includes 'these guys' and the mammals. Collectively, these are now called the amniotes - not proto-amphibians, but descendants of a branch of the amphibians (that had adapted to dry land). It used to be that any amniote, alive or dead, that wasn't a bird or a mammal was called a reptile (even if that was 'mammal-like reptile'). Now, they're restricting the use of 'reptile' to the last common ancestor of all of today's reptiles, and all of its descendants.

Here's a Wikipedia diagram:

http://en.wikipedia.org/wiki/Amniote#Cladogram_of_Amniotes